GP on upcoming rivbike fits, sloping top tubes, trail, flex, rolling resistance
CycloFiend
It would've been posted yesterday, but I'm several notches under the weather
this week.
-------
New RIV bike geos and fits:
The 48 will fit like a horizontal top tube (htt) of a 51 or to to 56 or so.
The 52, like a 53 to 60; the 56, like a 57 to 63 or so, and the 60, like a
62 to about-how-we-say-a 66. The explanation is simple, and it is: The top
tube slopes UP from the seat lug, NOT down from the head tube. So front-end
height is easily had. If you're on the small end of a new bike size, you'll
probably sink the stem in deep---an odd thing for most Rivvies (I think
that's a Beth Hamon term, not sure), but with the SU (sloping UP) top tubes
(TT), it makes sense. Saddle height is never a problem, not with today's
500mm seat posts.
So...the new sizes will fit a gigantic range of riders, all with four sizes.
I know the SUTT's don't have that Stradivarius look, but the goal of these
new bikes is to make solid, fantastic, versatile, comfortable, lugged steel
bicycles affordable to more people; to make it easier to buy (for instance)
an Atlantis-style bike (touring) even if you can't justify a $3,000 real one
because you aren't a full-time wealthy vagabond. Our bikes have a certain
look, and these will too. But the function and the sense of the SUTT seems
appropriate for the new bikes, and I think it's good to apply a different
Aesthetic Yardstick to a $700 frame than to one that costs twice or more of
that.
The Bleriot has "that Rivendell look," true, but we could never afford to
buy enough of them by ourselves (without QBP's help) to be able to stock
sizes deep enough to ensure good supply, and that matters.
The SUTT is only 6-degrees, or about four more degrees than our current
bikes. It is the same as the BOMBADIL, which you can see on our site. So:
I'm a fan of these bikes even before they're here. Of course, on one hand I
have to be. But on the other hand, we're the force behind them---they
aren't being forced on us, and now we gotta defend them. Not at all. I'm
really excited about them.
These days, to me, a nicely detailed bike that forces on you a low bar and
skinny tires. I look at bar height-ability and tire-ability...and lugs,
somewhere along the line.
TRAIL:
I'm GETTING tired of this topic, and have only this to say, for now: You can
get used to anything and learn to love it. The power of suggestion is
strong, especially in Matters of Subtle Differences and Subjectivity. All
that said, Trail is a stabilizing force, which means to some extent is can
make a bike safer to ride, less easily jostled-to-crash than a bike with too
little of it.
I'm not one to quake at the thought of going against the conventional wisdom
when I think it's off, but in this case I don't think it's off. If it were
off, then the tens of millions of happy bikes and riders in the last half
century and before wouldn't have been so happy and content. I understand
that THAT logic can't be applied as successfully to all matters in and out
of bike design, but I think it can apply to trail. There may be certain
circumstances that benefit from a little more or a little less (with the
extremes of riding out there, it would have to be that way), but for
day-in/day-out riding, trail figures in the high fifties to low sixties work
great.
Here's an odd fact that is troubling me some: The current 52 Bombadil, the
one so many people have ridden (including Chico Gino, who reported on it in
his blog), rides great by All Accounts. I have never ridden a bike that rode
an iota better, more pleasantly, easy flowing, easy to control, slippery and
grippy in all the right places. I have ridden it on several S240s with
weights ranging from 27 to 55 pounds, and no problem, it feels like a bike.
Unloaded, it feels like a road bike (too much like one, for my taste). The
troubling part is: 68mm of trail. It is troubling because "trailists" will
see that figure (or figure it out from other numbers) and doubt the bike
they'll never even ride. Trail theory says it should suc* going uphills
slow, yet it doesn't. So right now and over the next week or so I have to
decide between sticking with something that I know works, or "designing to
theory." If I do that, I'll dig into my bank of experience or whatever it
is and make a conservative shot, but if I do that, I'll feel like I'm caving
in. A slight loss of self-respect, but fewer future headaches?
FLEX:
A certain amount is fine, too much is not, and it's not a significant source
of "energy/speed loss." If you believe that a bike can't be too rigid, then
you'll naturally like rigid bikes better, and equate them with goodness and
speed. If you believe a little flex feels good and doesn't slow you down,
might even help the way a flexy dance floor or gym floor helps the jumps,
then you'll enjoy the slight, nearly but not quite imperceptable flex in a
moderate frame. Too much flex is a problem when it causes "ghost shifting,"
which is real shifting caused by the fame flexing enough to move the rear
hub away from the upper pulley, resulting in the chain being de-railed to
the next hardest cog. If you're too much guy for a particular frame, you may
find this happening on steep climbs; but check your shift lever tightness
first, and make sure there's no excess friction in the system. Other
opinions abound, and seek 'em out!
Rolling resistance varies tremendously with the surface and tire pressure.
The prevailing opinion, which I go along with, says that rougher roads need
softer tires that roll over and absorb the bumps, rather than hitting them
and bouncing skyward. One example of "conventional tire wisdom" that I
doubt-to-don't-believe, is the idea that a supple sidewall makes a whopping
difference. Sidewall suppleness is most obvious when there's no air in the
tire, and even MORE MOST obvious when the tire isn't even on a rim. Once you
mount and inflate two tires, one with a supple sidewall (SS) and one with a
firmer sidewall (FS), then the differences are insignificant. If both tires
inflate to 75psi feel different, then they will behave differently, too. To
make the FS feel like the SS, you may have to reduce its psi by 5, and there
are no drawbacks to doing that.
But here again, it's kind of a case of magnifying amoebas, since (1)
compared to wind resistsance, rolling resistance is insignificant, and
matters only in races won or lost by wheel-widths; and (2) for anybody who
doesn't race at that supremely high level, it is a mistake (I'd say) to even
give it a second thought. You want a comfortable, reliable bike; a certain
amount of fitness; a friend to ride with, and a safe place to ride. If the
weather's good and the scenery is decent, that's all you need. That's not to
say you shouldn't enjoy discussions about bicycle theoretics, but in the
end, don't forget to re-size their importance...is all.
BUILDER:
New builder is not anybodyanybody knows, I am sure. Builders come with
various degrees of fame and reputation, but no builder imbues a frame
with magical love that flows from his fingertips. It's a romantic
notion, and I'd be the first to acknowledge that the range of skills,
especially in custom builders, varies far more than the prices they
charge. In a custom Riv builder, I am looking for a guy who loves
bicycles and is at home with metal and tools, and has personal metal-
making standards that are higher than my own, and won't take short
cuts. I also look for, and have found somebody with decades (more than
three) of experience building some of his own frames (including a
custom for me way back) and repairing hundreds of the finest frames in
the world. I know it is impossible to stop the speculation, so
speculate away, but in the end, it will be a RIvendell frame, not a
_______ _________ frame, because it is our design, our lugs, our
concept, our choice of everything. Frames from him are still
months&months away, and when they finally start to flow, they will
flow glacial-like!
Best, Grant
Ryan Watson
Lots of topics that interest me in this one!
On Fri, 16 May 2008, CycloFiend forwarded what Grant P. wrote:
> Trail is a stabilizing force, which means to some extent is can
> make a bike safer to ride, less easily jostled-to-crash than a bike with too
> little of it.
I think he's got that backwards. Lower trail seems to be less bothered by
jostling. I noticed that comparing my Bleriot to my Kogswell. The B was
much more likely to get "off course" (due to wind, accidental bumping
of the bars, inattention, etc) except at very high speeds, where
they seemed equally stable, but with distinctly different feel. I've yet
to crash on either one.
I don't think Riv needs to go the low-trail route, but too high doesn't
feel good to me. I actually don't notice much difference between 30, 40,
and 50mm of trail, but 60+ feels wierd. I don't think "you can get used to
it" is a good answer when considering an expesive bike.
> FLEX:
> moderate frame. Too much flex is a problem when it causes "ghost shifting,"
> which is real shifting caused by the fame flexing enough to move the rear
> hub away from the upper pulley, resulting in the chain being de-railed to
> the next hardest cog.
I love flex and will never buy another stiff bike. Unfortunately this may
rule out future Rivendells for me, unless I get a custom. Is this ghost
shifting something unique to modern narrow 9-10
speed clusters? I've ridden some very flexy frames up some very steep
hills, but never had that problem with 6-7-8 speed systems.
> But here again, it's kind of a case of magnifying amoebas, since (1)
> compared to wind resistsance, rolling resistance is insignificant, and
> matters only in races won or lost by wheel-widths; and (2) for anybody who
> doesn't race at that supremely high level, it is a mistake (I'd say) to even
> give it a second thought.
I disagree. Once you've found a comfortable postion on the bike, you can't
really do anything about wind resistance without comprimising comfort.
You can improve the tires, though. Faster tires tend to be more comfy
anyway, so it's win-win! I've seen low rolling resistance tires make the
difference between pedalling with a tailwind and being able to just coast along.
I don't really care about speed, but tires that feel faster are simply
more fun than ones that feel sluggish. I really wish Riv would have
Panaracer make a Maxy Fasty with the same construction they use for the
Grand Bois tires. It would be simple to do and make for a fabulous
fast and comfy tire. I'll pre-order four of them!
Thanks for letting me ramble on,
Ryan
Murray Love
Thanks for posting this.
Lots of topics that interest me in this one!
I think he's got that backwards. Lower trail seems to be less bothered by
On Fri, 16 May 2008, CycloFiend forwarded what Grant P. wrote:
> Trail is a stabilizing force, which means to some extent is can
> make a bike safer to ride, less easily jostled-to-crash than a bike with too
> little of it.
jostling. I noticed that comparing my Bleriot to my Kogswell. The B was
much more likely to get "off course" (due to wind, accidental bumping
of the bars, inattention, etc) except at very high speeds, where
they seemed equally stable, but with distinctly different feel. I've yet
to crash on either one.
Agreed. Less trail = a less perturbable front end, but also requires greater steering input to effect a change in direction. Having said that, my current favourite bike ever (edging out the RB-1 on the versatility front) is my '84 Specialized Sequoia, which has medium trail (~55mm) and handles perfectly well. All else equal, I prefer lower trail, but it's not the first thing I look at. These days, that would be...
> FLEX:
> moderate frame. Too much flex is a problem when it causes "ghost shifting,"I love flex and will never buy another stiff bike. Unfortunately this may
> which is real shifting caused by the fame flexing enough to move the rear
> hub away from the upper pulley, resulting in the chain being de-railed to
> the next hardest cog.
rule out future Rivendells for me, unless I get a custom. Is this ghost
shifting something unique to modern narrow 9-10
speed clusters? I've ridden some very flexy frames up some very steep
hills, but never had that problem with 6-7-8 speed systems.
I think Dave Mann over on iBOB reported ghost-shifting issues with his early-80s 531 Treks, but he's the first to point out that this is probably an effect of Trek using very light (probably .8/.5/.8) tubing on a very large frame (he rides a 64cm). I expect the old ultra-flexy bonded-aluminum Vitus 979s and the like might have experienced similar problems, especially in larger sizes, but the typical non-OS bike feels perfectly solid, especially in the regular tubesets and common sizes. My '92 RB-1 was probably on the light side for steel production bikes in its size (59cm), and never a hint of ghost-shifting.
Murray
Victoria, BC
RonLau
raise your handlebar without a stem up all the way to its limit.
Looks funny IMO.
Another factor which I believe, and others as well is a compact frame
has more "snap" to it. Keep in mind this is my belief based on my
experience, YMMV for sure.
Doug Shaker
wheel flop at the same time. I may not understand correctly, but
if I do, then anything that increases trail will also increase wheel
flop. And, sure enough, trail DOES stabilize, but wheel flop
de-stabilizes. When there is little weight on the front fork, the
trail stabilization effect dominates. When there is lots of
weight on the front wheel, then the wheel flop effect dominates.
At low speeds, going up hill, with a full load on the front wheel,
wheel flop REALLY dominates (personal experience).
Discussing trail without knowing how you are going to use and load
the bike is not very meaningful.
But, I could have misunderstood all this. If that is so, I would
love to have someone correct me and then maybe I will finally understand
it.
-Doug "anonymous" Shaker
At 10:24 AM 5/16/2008, you wrote:
- > Trail is a stabilizing force, which means to some extent is can
- > make a bike safer to ride, less easily jostled-to-crash than a bike with too
- > little of it.
- I think he's got that backwards. Lower trail seems to be less bothered by
- jostling. I noticed that comparing my Bleriot to my Kogswell. The B was
- much more likely to get "off course" (due to wind, accidental bumping
- of the bars, inattention, etc) except at very high speeds, where
- they seemed equally stable, but with distinctly different feel. I've yet
- to crash on either one.
Agreed. Less trail = a less perturbable front end, but also requires greater steering input to effect a change in direction. Having said that, my current favourite bike ever (edging out the RB-1 on the versatility front) is my '84 Specialized Sequoia, which has medium trail (~55mm) and handles perfectly well. All else equal, I prefer lower trail, but it's not the first thing I look at. These days, that would be...
Murray Love
I don't think it is much use to discuss trail without discussing
wheel flop at the same time. I may not understand correctly, but
if I do, then anything that increases trail will also increase wheel
flop. And, sure enough, trail DOES stabilize, but wheel flop
de-stabilizes. When there is little weight on the front fork, the
trail stabilization effect dominates. When there is lots of
weight on the front wheel, then the wheel flop effect dominates.
At low speeds, going up hill, with a full load on the front wheel,
wheel flop REALLY dominates (personal experience).
Discussing trail without knowing how you are going to use and load
the bike is not very meaningful.
But, I could have misunderstood all this. If that is so, I would
love to have someone correct me and then maybe I will finally understand
it.
-Doug "anonymous" Shaker
That's a good summary, Doug. I kind of regard wheel flop (the vertical drop of the axle as the front wheel is turned) as a secondary effect of trail. It isn't quite that simple, since it is proportional to trail and head angle, but then trail is itself a partial function of head angle, so...
In simple terms, wheel flop tends to amplify steering inputs, and I believe it is the major reason why high-trail bikes are easier to put off-course, either deliberately or accidentally.
My comments on trail were in the context of a moderate rear load (Nelson saddlebag) with no front load.
Murray
Victoria, BC
jim g
On May 16, 1:10 pm, Doug Shaker <d...@theshakers.org> wrote:
> I don't think it is much use to discuss trail without discussing
> wheel flop at the same time.
+ is low trail combined with a skinny, high-pressure tire bad?
+ is high trail combined with a wide, low-pressure tire good?
These are some questions I want to learn the answers to.
See also:
http://sfcyclotouring.blogspot.com/2008/01/apples-to-apples-or-frank-discussion-of.html
http://sfcyclotouring.blogspot.com/2008/05/kogswell-700c-pr-first-impressions.html
-Jim G
Grantm...@gmail.com
and
"....looks ridiculous." Sometimes a NICE ridiculous, but still...
Grant
PATRICK MOORE
Aaron Thomas
I've experimented with CdlVs and Maxy Fasties on my Bleriot and can't
detect a huge difference in handling, especially as regards wheel
flop. But I wonder what could (theoretically) happen by putting a
fatter, larger diameter tire on, such as the Hetre. Would that affect
flop and/or tracking? And if so, in what ways?
Aaron
On May 16, 1:46 pm, jim g <yoj...@gmail.com> wrote:
> On May 16, 1:10 pm, Doug Shaker <d...@theshakers.org> wrote:
>
> > I don't think it is much use to discuss trail without discussing
> > wheel flop at the same time.
>
> and/or TIRES and their PRESSURE. E.g.:
>
> + is low trail combined with a skinny, high-pressure tire bad?
> + is high trail combined with a wide, low-pressure tire good?
>
> These are some questions I want to learn the answers to.
>
> See also:
>
>
> -Jim G
It Depends
new SUTT frames, which sound like they might offer better potential
fits to "non-standard" body types (and even possibly "standard female"
body types) than do the current production Rivs.
The trail and flex debates seem largely personal and subjective; I
empathize with Grant growing tired of them. Rolling resistence ain't
like that, though, and Jan Heine's vigorous testing has shown pretty
conclusively that (1) it can generate substantial (~10% at cruising,
not racing, speeds) variations in speed even between ostensibly
similar tires and (2) supple sidewalls -- along with thin, smooth
tread -- are indeed what matters. Grant knows all this, having
reviewed and responded to Jan's first tire test article. For him to
continue advancing discredited theory in the face of solid,
uncontroverted (as far as I know) empirical evidence is unbecoming.
(That's obviously not to say there aren't compelling durability or
other reasons to ride tires with tougher sidewalls and/or thicker
tread, but to claim that rolling resistence driven speed differences
are at the amoeba level is just nonsense.)
Tim McNamara
On May 16, 2008, at 1:09 PM, It Depends wrote:
> Thanks for posting this! I'll be very curious to see the specs on the
> new SUTT frames, which sound like they might offer better potential
> fits to "non-standard" body types (and even possibly "standard female"
> body types) than do the current production Rivs.
>
> The trail and flex debates seem largely personal and subjective; I
> empathize with Grant growing tired of them. Rolling resistence ain't
> like that, though, and Jan Heine's vigorous testing has shown pretty
> conclusively that (1) it can generate substantial (~10% at cruising,
> not racing, speeds) variations in speed even between ostensibly
> similar tires and (2) supple sidewalls -- along with thin, smooth
> tread -- are indeed what matters. Grant knows all this, having
> reviewed and responded to Jan's first tire test article.
Jan's tire testing wasn't all that rigorous IMHO and I remain
unconvinced. There were too many mutually incompatible statements
made by him at different times and different forums in defense of his
data, and the risk of confounds in the data was significant. There
is quite a bit of scatter in the data that shouldn't be there. The
confidence intervals overlap to the point that conclusions are very
difficult to draw except in the most extreme comparisons. His use of
the Analytic Cycling Web site as a demonstration of the differences
is sketchy at best due to problems with the site's modeling
methodology, which tends to exaggerate differences. Jan's an
intelligent guy, he's got a PhD in geology or something like that,
and he made a good-faith effort at real-life testing of tires. He's
tried to tackle things that most magazines have shied away from
(e.g., ten pages of discussion about trail rather than the "12 ways
to a stronger psoas for better climbing" type articles that plague
too many cycling magazines). The problem is that real life contains
too many variables to be sure you've measured the right one.
> For him to
> continue advancing discredited theory in the face of solid,
> uncontroverted (as far as I know) empirical evidence is unbecoming.
> (That's obviously not to say there aren't compelling durability or
> other reasons to ride tires with tougher sidewalls and/or thicker
> tread, but to claim that rolling resistence driven speed differences
> are at the amoeba level is just nonsense.)
For the type of riding Grant appears to enjoy, at least based on the
photos on the Riv Web site, rolling resistance would be a very moot
point indeed. Everything has to be looked at in context. Jan's
context is maximum performance on ultramarathon rides and something
that gives 0.1% gain in speed would be important to him. He weighs
things to the gram and the joule in that quest. Grant's context is
riding around on fire roads and mountain trails with some gear and
some friends for a picnic lunch or a S24O camping expedition. He may
weigh things to the pound and the peanut butter sandwich.
My thinking is getting more like Grant's/Riv's all the time. I raced
1992-2000 and stopped when I figured out that racing made cycling
into an exercise in misery. I rode brevets 2003-2007 and realized
this year that of the dozen-plus brevets I have done, I enjoyed about
three of them and the rest were awful. I've ridden 5,000-7,000 miles
a year for the past 16 years and rode probably 3,000 miles a year for
20 years before that. I've come to the conclusion that life has
enough times that suck without volunteering for more suckitude.
Overcoming unnecessary self-inflicted adversity doesn't boost my self-
esteem, it makes me wonder how come I'm such a schmuck to be out
there in those conditions.
So now I ride because it's fun, on nice days when it's not going to
be a slog and I'm going to spend most of my time wishing I was doing
almost anything but riding my bike. It ain't righteous, it ain't
saving the planet, and I've probably just sold out. I've ridden 1/3
of my normal miles this year. I come home from work and ride an hour
and a half instead of three hours. As a result I have time to do
stuff around the house without resenting the time lost from riding
and can study jazz guitar without feeling the dilemma of "do I ride
or do I play guitar?" On the down side I weigh 10 pounds more than
normal for this time of year.
Other people's interests are different and may they be blessed by
their personal deities for it. If riding 1200 km in under 90 hours
does it for someone, then go (wo)man go.
David Estes
--~--~---------~--~----~------------~-------~--~----~
A very thoughtful response. Thanks for taking the time to write it, Tim.
--
Cheers,
David
Redlands, CA
Mike
Tim McNamara
> Agreed. Thanks Tim.
>
>> A very thoughtful response. Thanks for taking the time to write
>> it, Tim.
Gee, you're welcome <blush>. Re-reading my post, though, I realized
that I set up a false dichotomy there. I put Jan's approach and
Grant's approach in opposition, and I'd bet that they wouldn't see it
that way and would have a lot of fun on a bike ride together.
Especially since I've never met either of them, it was not so smart
to be putting words in their mouths. Consider it a comparison and
contrast between the respective editorial tendencies of Riv Reader
and Bike Quarterly. Maybe Grant does brevets on the sly and doesn't
mention it and maybe Jan goes on the occasional S24O without
publishing it in his magazine.
In bicycling there is almost always a lot of overlap in different
styles of and approaches to riding. Pootlers on three speeds riding
around Lake Pepin (today is the first day of the 3 Speed Tour of Lake
Pepin) and racers in Giro have more in common than might be apparent
at first glance.
Doug Shaker
and just let folks choose between a 68mm trail fork and something
with a lower trail.
At 07:47 AM 5/16/2008, you wrote:
>Here's an odd fact that is troubling me some: The current 52 Bombadil, the
>one so many people have ridden (including Chico Gino, who reported on it in
>his blog), rides great by All Accounts. I have never ridden a bike that rode
>an iota better, more pleasantly, easy flowing, easy to control, slippery and
>grippy in all the right places. I have ridden it on several S240s with
>weights ranging from 27 to 55 pounds, and no problem, it feels like a bike.
>Unloaded, it feels like a road bike (too much like one, for my taste). The
>troubling part is: 68mm of trail. It is troubling because "trailists" will
>see that figure (or figure it out from other numbers) and doubt the bike
>they'll never even ride. Trail theory says it should suc* going uphills
>slow, yet it doesn't. So right now and over the next week or so I have to
>decide between sticking with something that I know works, or "designing to
>theory." If I do that, I'll dig into my bank of experience or whatever it
>is and make a conservative shot, but if I do that, I'll feel like I'm caving
>in. A slight loss of self-respect, but fewer future headaches?
- Doug "Anonymous" Shaker
CycloFiend
>
> If it was me making this decision, I would follow Kogwells' lead
> and just let folks choose between a 68mm trail fork and something
> with a lower trail.
>
I think that ends up putting an inordinate amount of weight on one variable.
Trail is one of 'em, as is head angle, bb drop, wheelbase, etc. My
preference is to let the bicycle designer work all that out and provide a
bicycle which handles well under the conditions I'm likely to use it for.
I'm certainly not against low trail or high trail designs - just not
convinced that it is the predominant driving influence on handling. I'd
much rather ride any bike from any competent bike designer who says "this is
how I want it to handle" before worrying about most measurements other than
fit.
- Jim
--
Jim Edgar
Cyclo...@earthlink.net
Send In Your Photos! - Here's how: http://www.cyclofiend.com/guidelines
"That which is overdesigned, too highly specific, anticipates outcome; the
anticipation of outcome guarantees, if not failure, the absence of grace."
William Gibson - "All Tomorrow's Parties"
Michael Wise
wheel size, head tube angle, fork rake. It gives you a standardized
way of looking at the handling of different bikes: the rake of the
low-trail fork on my 700C bike is different from that on the 650B, but
the trail measurement is the same, and the handling is quite similar.
It's also really easy to show: just draw an imaginary line straight
down from the headtube to the ground, and indicate the short
difference between the line and the contact patch of the tire.
--
How often I have lain beneath rain on a strange roof, thinking of home.
Philip Williamson
I think 40mm of trail with a 74 degree headtube will handle differently than 40mm with a 72 headtube.
How differently? No idea.
Philip
CycloFiend
> But trail is a combination of a number of different measurements:
> wheel size, head tube angle, fork rake. It gives you a standardized
> way of looking at the handling of different bikes: the rake of the
> low-trail fork on my 700C bike is different from that on the 650B, but
> the trail measurement is the same, and the handling is quite similar.
> It's also really easy to show: just draw an imaginary line straight
> down from the headtube to the ground, and indicate the short
> difference between the line and the contact patch of the tire.
Those are good points, Michael. I definitely over-simplified things in my
statements.
My comments were really with respect to the idea of folks not trying the
Bombadil simply because of a trail measurement. In the 10 or 15 minutes that
I've had to ride La Bomba around the RBWHQ&L parking lot, I was pretty
impressed by its handling and low speed nimbleness. If that's 68 mm of
trail, I'd say "ok".
I would reckon that you can put together two bikes with identical trail and
by modifying other factors such as TT length and BB drop, have recongnizably
different handling bicycles.
I'm sure a lot of my preferences have to do with the terrain around these
parts, and my build and techniques. It's rare that I'll have more than five
pounds in a bar bag or front rack load.
all the best,
- Jim
--
Jim Edgar
Cyclo...@earthlink.net
Cyclofiend Bicycle Photo Galleries - http://www.cyclofiend.com
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"Then I sat up, wiped the water out of my eyes, and looked at my bike, and
just like that I knew it was dead"
-- Robert McCammon, "Boy's Life"
Bill Connell
> My comments were really with respect to the idea of folks not trying the
> Bombadil simply because of a trail measurement. In the 10 or 15 minutes that
> I've had to ride La Bomba around the RBWHQ&L parking lot, I was pretty
> impressed by its handling and low speed nimbleness. If that's 68 mm of
> trail, I'd say "ok".
I think this observation also points out a couple of other
considerations. Does a desired trail number in one tire size
necessarily transfer directly to another tire size? Even if the outer
tire diameter is identical, the pneumatic trail and handling will be
different and might require a different geometric trail. Also, why
wouldn't the desired trail for a mountain bike be different than that
for a road bike? I find it interesting that the test rides of the
Bombadil, have mentioned the nimble handling (Grant said almost too
road-like), despite the apparently high trail figure. In the Bombadil
you have a different usage and different wheel size than almost any
other bike, so naturally the numbers should look different.
I find the discussions on trail interesting but entirely
non-conclusive. I also find myself wishing i could afford a Bombadil,
but that's another problem entirely.
--
Bill Connell
St. Paul, MN
Tim McNamara
On May 17, 2008, at 4:49 PM, Michael Wise wrote:
> But trail is a combination of a number of different measurements:
> wheel size, head tube angle, fork rake. It gives you a standardized
> way of looking at the handling of different bikes: the rake of the
> low-trail fork on my 700C bike is different from that on the 650B, but
> the trail measurement is the same, and the handling is quite similar.
> It's also really easy to show: just draw an imaginary line straight
> down from the headtube to the ground, and indicate the short
> difference between the line and the contact patch of the tire.
Right, but all trail is not created equal (to hack a phrase). 50 mm
trail on a bike with a 68 degree head tube will feel different than a
bike with 50 mm of trail and a 73 degree head tube.
The geometry of bicycle handling is complex and has not been
definitively worked out in terms of the math. Bikes frequently
handle differently than predicted from trail numbers. The geometry
we use was basically worked out by blacksmiths using the tried-and-
true methods of reiterative experimentation.
The trail numbers we use assume a contact patch that is a geometric
point. In life we ride on tires, which have a contact patch and in
turn this affects the practical effects of trail and makes
mathematical description even harder. BQ had a piece on "pneumatic
trail" a while back that was quite interesting and thought provoking.
RonLau
picture.
Weight distribution, IMO, is far more important that trail alone. If
you want lots of good information about bicycle handling, take a look
at Dave Moulton Blog and his web site.
Also I found how much weight you put on the bar has a lot to do with
how this bike handle as well.
http://davesbikeblog.blogspot.com/
http://prodigalchild.net/Bicycle.htm
Ron
Michael Wise
I reference Kogswell and Matthew Grimm here because more than anyone
he has been able to make low-trail front-loading bikes a reality. He
even offered low-trail forks as replacements for the forks that
originally came on the earlier single-speed/fixed 700C model G. I have
one of these installed, and the handling is indeed just like the 650B
P/R that I also have.
So, to throw some numbers into the calculator: 690mm for wheel size for both:
74º head tube needs 57mm fork offset to achieve 40mm trail, with flop of 12
72º head tube needs 69mm fork offset to achieve 40mm trail, with flop of 11
I would contend that these two bikes would probably handle very
similarly, except that 69mm fork offset is impractically high: I doubt
you could get such a fork made. So if you spec a 72º head tube you are
much more likely to get higher trail numbers, which will affect the
handling.
Michael Wise
>
> on 5/17/08 2:49 PM, Michael Wise at mish...@gmail.com wrote:
>
>> But trail is a combination of a number of different measurements:
>> wheel size, head tube angle, fork rake. It gives you a standardized
>> way of looking at the handling of different bikes: the rake of the
>> low-trail fork on my 700C bike is different from that on the 650B, but
>> the trail measurement is the same, and the handling is quite similar.
>> It's also really easy to show: just draw an imaginary line straight
>> down from the headtube to the ground, and indicate the short
>> difference between the line and the contact patch of the tire.
>
> Those are good points, Michael. I definitely over-simplified things in my
> statements.
>
> My comments were really with respect to the idea of folks not trying the
> Bombadil simply because of a trail measurement. In the 10 or 15 minutes that
> I've had to ride La Bomba around the RBWHQ&L parking lot, I was pretty
> impressed by its handling and low speed nimbleness. If that's 68 mm of
> trail, I'd say "ok".
>
I agree with you, Jim. High trail is no reason to be put off by a
bike. As Grant said, it's pretty much been this way for a while now,
and if there was something really wrong with high trail, someone would
have fixed it. The advantages of low trail go right out the window if
you carry a heavy load on the rear, or no load at all, front or back,
or a light load in front and heavy load in back; all that you are left
with are the disadvantages, such as the poor handling that Grant
describes.
I spec my bikes as industrial workhorse in front, with large chunky
racks, big Schmidt front hubs, headlights and mudflaps and cables, and
simple, sinuous lines in back, so low trail works for me practically
and aesthetically, but may not work for everyone.
Tim McNamara
On May 18, 2008, at 11:59 AM, Michael Wise wrote:
> So, to throw some numbers into the calculator: 690mm for wheel size
> for both:
>
> 74º head tube needs 57mm fork offset to achieve 40mm trail, with
> flop of 12
>
> 72º head tube needs 69mm fork offset to achieve 40mm trail, with
> flop of 11
>
> I would contend that these two bikes would probably handle very
> similarly, except that 69mm fork offset is impractically high: I doubt
> you could get such a fork made. So if you spec a 72º head tube you are
> much more likely to get higher trail numbers, which will affect the
> handling.
Well, you'd have to try it and see. You'd notice the difference for
the first minute or so and then only occasionally after switching
bikes, because you quickly adapt. But to make the comparisons
meaningful, you'd need to use the same tires and inflation. It's
been noted by others such as Jan Heine that low trail/small highly
inflated tires feels unstable and that such bikes tend to handle
better with larger tires. The larger tires offset the lower
stability (self centering tendency) with a typically larger contact
patch and lower pressure. Try a 30 mm trail Kogswell P/R with 700 x
23s pumped up to 120 psi. You'll get used to it, but it will feel
unstable at first.
69 mm is just under 2 3/4" offset which was not uncommonly used in
the UK for tandems and single road bikes (Jack Taylor, for instance,
used 73 degree head tubes and fork offsets in the 2 1/2" to 2 3/4"
range). Raleigh used such fork offsets all the time on their three
speeds.
http://www.classiclightweights.co.uk/designs/hsjacktaylor.html
For road bikes in the past 30-40 years, fork offsets have gotten
smaller and trail has gotten correspondingly greater, reflecting both
changing tastes and changing conditions. Modern "high" trail bikes
(55-60 mm) came from Continental bike racing and developed as road
quality improved, tires got smaller and more highly inflated to
reduce rolling resistance- road bike steering geometry got more like
track bike geometry. These bikes are steered by the seat of the
pants, leaning rather than steering with the bars. My old track
bike, with more than 60 mm trail, was the easiest bike to ride no-
handed that I have ever been on for this reason. Trail creates a
lever force on the steering axis of the fork.
With US road quality deteriorating at a frightening pace thanks to
deficit spending cutting in to maintenance budgets, low trail bikes
with fat tires may be on a comeback!
jim g
I previously posted with a link to my blog where I wrote about my
experiences with my newly-built Kogswell 700C P/R bike, assembled with
what is supposed to be a 40mm trail fork. But I'll take a moment to
highlight my findings...
I feel somewhat let down: there ARE some handling differences, but
they are exceedingly subtle. If I didn't know I was riding a "low-
trail" bicycle, it's not something that I would've picked up on.
There's definitely not a night-and-day difference. Maybe if I load
this bike with 10lbs on a front rack it'll be different, but until
then I don't know.
I did also get the 30mm trail fork and I will try that out at some
point -- perhaps then the differences will be more pronounced?
So far I've put just under 100 miles on this bike, and I'm still
adjusting the fit and working out the kinks. I think next time, I'll
ride my 650B RB-1 and take some more notes...
-Jim G
Jim Bronson
> The trail and flex debates seem largely personal and subjective; I
> empathize with Grant growing tired of them. Rolling resistence ain't
> like that, though, and Jan Heine's vigorous testing has shown pretty
> conclusively that (1) it can generate substantial (~10% at cruising,
> not racing, speeds) variations in speed even between ostensibly
> similar tires and (2) supple sidewalls -- along with thin, smooth
> tread -- are indeed what matters. Grant knows all this, having
> reviewed and responded to Jan's first tire test article. For him to
> continue advancing discredited theory in the face of solid,
> uncontroverted (as far as I know) empirical evidence is unbecoming.
> (That's obviously not to say there aren't compelling durability or
> other reasons to ride tires with tougher sidewalls and/or thicker
> tread, but to claim that rolling resistence driven speed differences
> are at the amoeba level is just nonsense.)
I don't know. I've been riding Grand Bois for the last 9 months,
Jan's favorite tire. They are indeed great, but they don't last that
long, I have yet to get 2000 miles out of a pair.
So this weekend for the Austin 600K I mounted a pair of 28c Ruffy
Tuffies. I didn't really notice that I felt appreciably slower, and
my time was inbetween hte times for my other two 600K's I have done
this year. This ride was 35:40, other rides on Grand Bois were 33:02
and 37:30. What was even better was that, I did not get a flat. We
had very severe storms on the Wednesday before the brevet in the
Austin area and I was worried about debris and glass in the road, and
there was definitely some. We also had a 30 mile stretch of loose
chip seal.
One other thing I noticed was that how much better the handling on the
bike was with the narrower tires. My custom Riv was designed for
short reach brakes and 28mm tires. The handling feels a bit numb with
the Grand Bois. With the Ruffies it felt a lot more lively without
being darty at all. I think the next time I run the Grand Bois, I
will probably order the 28mm version.
So in short, I think you have to take rolling resistance as one facet
of overall tire performance. I wouldn't hesitate to run the Ruffy
Tuffies again. However, on my upcoming 1200K, I will probably run the
Grand Bois as absolute lowest rolling resistance will be paramount.
It Depends
> On May 16, 2008, at 1:09 PM, It Depends wrote:
>
> > Thanks for posting this! I'll be very curious to see the specs on the
> > new SUTT frames, which sound like they might offer better potential
> > fits to "non-standard" body types (and even possibly "standard female"
> > body types) than do the current production Rivs.
>
> > The trail and flex debates seem largely personal and subjective; I
> > empathize with Grant growing tired of them. Rolling resistence ain't
> > like that, though, and Jan Heine's vigorous testing has shown pretty
> > conclusively that (1) it can generate substantial (~10% at cruising,
> > not racing, speeds) variations in speed even between ostensibly
> > similar tires and (2) supple sidewalls -- along with thin, smooth
> > tread -- are indeed what matters. Grant knows all this, having
> > reviewed and responded to Jan's first tire test article.
>
> Jan's tire testing wasn't all that rigorous IMHO and I remain
> unconvinced.
number of folks plainly -- and loudly -- agree with you. Mainly on
quasi-religious grounds, as far as I can tell. Those "debates" have
the same distinctive tone as the "debates" over whether we're cooking
the earth, or whether smoking cigarettes causes lung cancer. I have
no desire to subject anyone to a rehashing (so, tough as it is, I'll
just hold my tongue w/r/t the conclusory statements that follow), I'm
just saying that there's been a lot of shouting down the heretic but
nary a shred of contrary evidence offered.
rolling resistence on paved roads might just affect rolling resistence
on fire roads), but he doesn't argue that the issue is moot, he argues
that rolling resistence isn't materially affected by sidewall
suppleness. And that argument, according to the best evidence we
have, is simply wrong.
> Everything has to be looked at in context. Jan's
> context is maximum performance on ultramarathon rides and something
> that gives 0.1% gain in speed would be important to him.
just wave your magic mouse and drop the impact of rolling resistence
on speed by two orders of magnitude: We're talking about 10% here,
not 0.1%.
> He weighs
> things to the gram and the joule in that quest. Grant's context is
> riding around on fire roads and mountain trails with some gear and
> some friends for a picnic lunch or a S24O camping expedition. He may
> weigh things to the pound and the peanut butter sandwich.
on my bike than Grand Bois. I'd happily make the speed for durability
trade-off. But I wouldn't pretend the trade-off didn't exist.
[snip!]
Jim Bronson
>
> On May 17, 1:13 am, Tim McNamara <tim...@bitstream.net> wrote:
>> On May 16, 2008, at 1:09 PM, It Depends wrote:
>
> That may well be true (or it might not -- the same factors that affect
> rolling resistence on paved roads might just affect rolling resistence
> on fire roads),
[snip]
"It depends", you lose a bit of credibility here. You know as well as
I do that the Grand Bois would not last very long on any fire road
that includes sharp rocks. I understand the argument about sidewall
flex perhaps also enhancing offroad rolling resistance, or lack
thereof. But considering the desired characteristics of a tire that
performs well on both pavement and fire roads, I think it's a straw
man argument.
regards,
Jim
--
I'm doing the Houston-Austin MS150 in 2008. I'll be riding 175 miles
by bicycle! Please consider supporting me in this worthy cause at my
e-donate link: http://www.ms150.org/edon.cfm?id=220459
Steve Palincsar
> Yeah, I'd like answers to Jim's questions too.
>
> I've experimented with CdlVs and Maxy Fasties on my Bleriot and can't
> detect a huge difference in handling, especially as regards wheel
> flop.
Well, you wouldn't, would you? Wheel flop is largely determined by head
angle.
> But I wonder what could (theoretically) happen by putting a
> fatter, larger diameter tire on, such as the Hetre. Would that affect
> flop and/or tracking? And if so, in what ways?
>
A wider tire like the Hetre should add pneumatic trail.
Steve Palincsar
> I don't think it is much use to discuss trail without discussing
> if I do, then anything that increases trail will also increase wheel
> flop.
You increase wheel flop by decreasing head angle. You can increase
trail by decreasing fork offset, which has no affect on trail.
John McMurry
Count the threads? Roll the casings between your fingers? Compare
thread angles?
Blindfolded, you'd never know the difference.
Add 75 pounds of air and those are the amoebas I think Grant's talking
about.
John McMurry
Burlington, VT
It Depends
>
> > On May 17, 1:13 am, Tim McNamara <tim...@bitstream.net> wrote:
> >> On May 16, 2008, at 1:09 PM, It Depends wrote:
>
> > That may well be true (or it might not -- the same factors that affect
> > rolling resistence on paved roads might just affect rolling resistence
> > on fire roads),
>
> [snip]
>
> "It depends", you lose a bit of credibility here. You know as well as
> I do that the Grand Bois would not last very long on any fire road
> that includes sharp rocks. I understand the argument about sidewall
> flex perhaps also enhancing offroad rolling resistance, or lack
> thereof. But considering the desired characteristics of a tire that
> performs well on both pavement and fire roads, I think it's a straw
> man argument.
[fire-road] riding, I'd rather have Jack Browns (or even Schwalbes) on
trade-off. But I wouldn't pretend the trade-off didn't exist."
obviously contained in the second clause, which you cut: "but [Grant]
doesn't argue that [rolling resistence] is moot [on fire trails], he
suppleness."
being made (indeed, the counterpoint to which *is* made elsewhere in
the same message) is the best way to challenge someone else's
credibility. Might say something about yours, though.
It Depends
[snip]
> Ever compare a cross-sectioned Grand Bois tire, to a National?
>
> Count the threads? Roll the casings between your fingers? Compare
> thread angles?
>
> Blindfolded, you'd never know the difference.
>
> Add 75 pounds of air and those are the amoebas I think Grant's talking
> about.
your argument.
Tim McNamara
>
> On May 17, 1:13 am, Tim McNamara <tim...@bitstream.net> wrote:
>> Jan's tire testing wasn't all that rigorous IMHO and I remain
>> unconvinced.
>
> From the "discussions" that erupted following Jan's tire tests, a fair
> number of folks plainly -- and loudly -- agree with you. Mainly on
> quasi-religious grounds, as far as I can tell. Those "debates" have
> the same distinctive tone as the "debates" over whether we're cooking
> the earth, or whether smoking cigarettes causes lung cancer. I have
> no desire to subject anyone to a rehashing (so, tough as it is, I'll
> just hold my tongue w/r/t the conclusory statements that follow), I'm
> just saying that there's been a lot of shouting down the heretic but
> nary a shred of contrary evidence offered.
I don't care to rehash all that. There were discussions in multiple
forums that I followed and I came away underwhelmed that the
confounds were adequately controlled- hand held timing, differences
in wind, differences in rider position, etc. These things resulted
in the large scatter seen in many of the measurements published by
Jan for several of the tires. Rolling resistance is not going to
change from one run to the next and any variation in that measurement
is due to error. I think that Jan and Mark did what they could, but
roll-down testing for rolling resistance is a fundamentally flawed
procedure- especially outdoors where even imperceptible wind of 0.5
mph can have a significant impact on speed. In the end I came away
with the impression that the BQ results ended up in the quasi-
religious camp. On the other hand, BQ's wind tunnel tests offer a
very good level of rigor and provide much useful information.
>> For the type of riding Grant appears to enjoy, at least based on the
>> photos on the Riv Web site, rolling resistance would be a very moot
>> point indeed.
>
> That may well be true (or it might not -- the same factors that affect
> rolling resistence on paved roads might just affect rolling resistence
> on fire roads), but he doesn't argue that the issue is moot, he argues
> that rolling resistence isn't materially affected by sidewall
> suppleness. And that argument, according to the best evidence we
> have, is simply wrong.
The best evidence that we have is that hysteresis losses in the
rubber and the tread patterns are by far the biggest contributors to
rolling resistance.
>> Everything has to be looked at in context. Jan's
>> context is maximum performance on ultramarathon rides and something
>> that gives 0.1% gain in speed would be important to him.
>
> Context is important, but intellectual honesty is more so. You can't
> just wave your magic mouse and drop the impact of rolling resistence
> on speed by two orders of magnitude: We're talking about 10% here,
> not 0.1%.
Sorry if that wasn't clear that I was not talking about rolling
resistance specifically but about any potential gain. And I remain
very unconvinced that rolling resistance amounts to a 10% difference
in speed. There are just too many other factors.
>> He weighs
>> things to the gram and the joule in that quest. Grant's context is
>> riding around on fire roads and mountain trails with some gear and
>> some friends for a picnic lunch or a S24O camping expedition. He may
>> weigh things to the pound and the peanut butter sandwich.
>
> And for that riding, I'd rather have Jack Browns (or even Schwalbes)
> on my bike than Grand Bois. I'd happily make the speed for durability
> trade-off. But I wouldn't pretend the trade-off didn't exist.
I don't think that Grant is offering that pretense but stating that
within his values it's just not very important. But he can speak for
himself on this and I don't want to put words in his mouth.
I'm also done on this topic as it threatens- as usual- to erupt into
all kinds of less-than-pleasantness. Ride what ya like, ride how ya
like, and have fun. That's what it boils down to as far as I am
concerned.
Gino Zahnd
And it would end up descending into an argument.
Cracks me up every single time, without fail. Thanks for all the laughs folks.
cyclofiend
> I'm also done on this topic as it threatens- as usual- to erupt into
> all kinds of less-than-pleasantness. Ride what ya like, ride how ya
> like, and have fun. That's what it boils down to as far as I am
> concerned.
_other_ lists that degrade into "less-than-pleasantness".
That sorta stuff just isn't appreciated or tolerated within these
walls.
- Jim, in list admin mode, at work...
cyclo...@earthlink.net
John McMurry
Have you ever had an opportunity to compare a cross sectional sample
of a Grand Bois tire with that of a National tire?
If you have, and took the time to compare the two; you will realize
that there are very minor differences between the two.
If you were handed the two samples blindfolded, you would not be able
to tell the differences in casing.
Now, if you add 75 pounds of pressure to these two casings, as an
example of a reasonable tire pressure, the detectible differences
between the two casings shrinks to be infinitesimally small.
Too small, in my opinion, to be able to discern among the other
variables present in the BQ tire test.
John McMurry
Burlington, VT
RonLau
Shaw. He showed me some old Vittoria tubular that was for 1km race on
the track, 190g, 19mm, thin as paper. Well, the tire sure was fast
but it only last for that race, yes, 1km.
It Depends
those all even out over multiple runs and the differences you're left
with are the ones you're trying to measure: differences in the
rolling resistance of tires, which, Jan's runs showed, can equate to
speed differences of ~10% at everyday riding speeds.
Okay, now I'm done, too. Thanks for your input and insights.
NickBull
camping bike ride. Looked like a fun ride. Not sure if it was quite
an "S24O." I'm not gonna hold my breath waiting for a GP ride report
on last weekend's 200K :-)
Along the lines of your comment about different types of bicyclists
having more in common than might be apparent ... to me, it's just
amazing to look at bicycles from the thirties and realize how feel
really substantive design changes have taken place since then.
Nick
On May 17, 11:29 am, Tim McNamara <tim...@bitstream.net> wrote:
> > Agreed. Thanks Tim.
>
> >> A very thoughtful response. Thanks for taking the time to write
> >> it, Tim.
>
> Gee, you're welcome <blush>. Re-reading my post, though, I realized
> that I set up a false dichotomy there. I put Jan's approach and
> Grant's approach in opposition, and I'd bet that they wouldn't see it
> that way and would have a lot of fun on a bike ride together.
> Especially since I've never met either of them, it was not so smart
> to be putting words in their mouths. Consider it a comparison and
> contrast between the respective editorial tendencies of Riv Reader
> and Bike Quarterly. Maybe Grant does brevets on the sly and doesn't
> mention it and maybe Jan goes on the occasional S24O without
> publishing it in his magazine.
>
> In bicycling there is almost always a lot of overlap in different
> styles of and approaches to riding. Pootlers on three speeds riding
> around Lake Pepin (today is the first day of the 3 Speed Tour of Lake
> Pepin) and racers in Giro have more in common than might be apparent
> at first glance.
Artie
one of the most important things that Grant mentioned on his original
posting. This is on the second paragraph:
“So...the new sizes will fit a gigantic range of riders, all with four
sizes.”
This has more implications on us than the religious discussion on
trail. By next year, we are going to be limited to four sizes for each
model that RBW will come out. Now, are we going to be satisfied with
that? This would mean that in order to fit on one of the four sizes,
we will do so by use of various combinations of seat posts and/or
stems.
This method of fitting riders on limited numbers of sizes of bikes
through use of seat posts and stems became the practice and espoused
by Specialized [I think(?)] when it came out with its so-called
“compact” framed bicycles [meaning sloping top tubes]. Some of us
roadies learned to live with it others did not.
>
> - Show quoted text -
Anne Paulson
>
> "So...the new sizes will fit a gigantic range of riders, all with four
> sizes."
>
> This has more implications on us than the religious discussion on
> trail. By next year, we are going to be limited to four sizes for each
> model that RBW will come out.
Hang on, isn't Rivendell keeping the present Atlantis design?
--
-- Anne Paulson
Jim Bronson
Regardless it does seem that Rivendell is moving towards a 3 tiered
model with the customs at the high end, the Atlantis/AHH/etc in the
middle and then low cost production models.
$0.02.
--
Randall Rupp
Rivendells. The current luxury models will all have the assortment of
sizes.
--
Randall Rupp
rcr...@gmail.com
Horace
We are all caught up in the discussion on trail that we have ignored
one of the most important things that Grant mentioned on his original
posting. This is on the second paragraph:
"So...the new sizes will fit a gigantic range of riders, all with four
sizes."
This has more implications on us than the religious discussion on
trail. By next year, we are going to be limited to four sizes for each
model that RBW will come out. Now, are we going to be satisfied with
that?
CycloFiend
> We are all caught up in the discussion on trail that we have ignored
> one of the most important things that Grant mentioned on his original
> posting. This is on the second paragraph:
>
> ³So...the new sizes will fit a gigantic range of riders, all with four
> sizes.²
>
> This has more implications on us than the religious discussion on
> trail. By next year, we are going to be limited to four sizes for each
> model that RBW will come out. Now, are we going to be satisfied with
> that? This would mean that in order to fit on one of the four sizes,
> we will do so by use of various combinations of seat posts and/or
> stems.
I think you are jumping the gun a bit there. Remember, he was talking about
the lower priced series to be made in Taiwan. I think it's reasonable to
expect some cost-cutting moves in order to deliver a product at a specific
price. These are sub-$700 (estimated) framesets. This is a set of three
models to replace the Bleriot. It seems to me to be a condition of
abundance.
I suspect folks will still save up a bit and purchase the Japanese and
American made frames, which have the full sizing run.
>
> This method of fitting riders on limited numbers of sizes of bikes
> through use of seat posts and stems became the practice and espoused
> by Specialized [I think(?)] when it came out with its so-called
> ³compact² framed bicycles [meaning sloping top tubes].
It was Giant with their OCR compact series.
- Jim
--
Jim Edgar
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CycloFiend
> This method of fitting riders on limited numbers of sizes of bikes
> through use of seat posts and stems became the practice and espoused
> by Specialized [I think(?)] when it came out with its so-called
> ³compact² framed bicycles [meaning sloping top tubes]. Some of us
> roadies learned to live with it others did not.
It was Giant with the OCR series of compact frames. They really took their
lead from the mtb industry, which had graduated to lower top tubes after
Ibis, WTB and a couple of other designers started using them. Grant has not
indicated that these will be compact at all.
- Jim
--
Jim Edgar
Cyclo...@earthlink.net
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alive."
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Bill Connell
>
> I read that to mean only the new low cost models had the more limited sizing.
>
> Regardless it does seem that Rivendell is moving towards a 3 tiered
> model with the customs at the high end, the Atlantis/AHH/etc in the
> middle and then low cost production models.
This was my reading too - existing models wouldn't change, and the
Taiwan construction/sloping TT design applies only to new
yet-to-be-named models. It'll be interesting to see how this works out
this time. Remember that the Romulus was a similar idea for a simpler,
lower-cost bike that was killed off for low profits (from what i
remember). Perhaps it just wasn't enough of a differentiation from the
standard production frames? I wished at the time that i could have
bought a canti-Rom, but in hindsight my complete Redwood was sort of a
steal (not cheap, but a great value).
--
Bill Connell
St. Paul, MN
jim g
> I think you are jumping the gun a bit there. Remember, he was talking about
> the lower priced series to be made in Taiwan. I think it's reasonable to
> expect some cost-cutting moves in order to deliver a product at a specific
> price. These are sub-$700 (estimated) framesets. This is a set of three
> models to replace the Bleriot. It seems to me to be a condition of
> abundance.
Sorry, couldn't resist. ;)
Seriously, this sizing technique does sound really similar to the way
Kogswell frames are (seemingly?) intended to fit.
-Jim G
Brewster Fong
>
> > We are all caught up in the discussion on trail that we have ignored
> > one of the most important things that Grant mentioned on his original
> > posting. This is on the second paragraph:
>
> > ³So...the new sizes will fit a gigantic range of riders, all with four
> > sizes.²
>
> > This has more implications on us than the religious discussion on
> > trail. By next year, we are going to be limited to four sizes for each
> > model that RBW will come out. Now, are we going to be satisfied with
> > that? This would mean that in order to fit on one of the four sizes,
> > we will do so by use of various combinations of seat posts and/or
> > stems.
>
> I think you are jumping the gun a bit there. Remember, he was talking about
> the lower priced series to be made in Taiwan. I think it's reasonable to
> expect some cost-cutting moves in order to deliver a product at a specific
> price. These are sub-$700 (estimated) framesets. This is a set of three
> models to replace the Bleriot. It seems to me to be a condition of
> abundance.
>
this with his new lower line of Colnagos, so why not Grant? Price
pointing a lower line is the trend. Besides Ernesto, Campy is doing it
with their new line of Fulcrum racing parts - all made in Taiwan and
substantially cheaper than the italian made stuff. In fact, just about
every "Italian" mfr has a carbon bike, now made in Taiwan and/or China
- Masi, Pinarello, Bianchi, Viner, Casati, Bottechia, Guerciotti, and
many more! These are all revered, exaulted names that once meant
Italy....no more!
However, subcombing to the temptation of building in Taiwan/China,
must really kill guys like Bruce Gordon, who rails against what he
calls the " marketers" (people who design frames and have them built
overseas), causing prices of framesets to be driven down.
Of course, not all builders are affected. People like Richard Sachs,
Vanilla (Sacha White), even Curt Goodrich and custom Rivendells (who
ever is building them) do command big $$$$ for their framesets and
have long waiting lists (3-4 years in some cases).
> I suspect folks will still save up a bit and purchase the Japanese and
> American made frames, which have the full sizing run.
>
dollar, then American made frames may be the way to go. There are many
American builders that can build something just as well as what Riv
offers.
>
> > This method of fitting riders on limited numbers of sizes of bikes
> > through use of seat posts and stems became the practice and espoused
> > by Specialized [I think(?)] when it came out with its so-called
> > ³compact² framed bicycles [meaning sloping top tubes].
>
> It was Giant with their OCR compact series.
>
Chinese made bikes, then I guess that saying of "Fistful of Seatpost"
is limited to his higher end bikes. I can see it now, a "Rivendell"
with a 330mm mtb seatpost! Oh, the horror, the horror....
Tim McNamara
On May 20, 2008, at 12:03 PM, Artie wrote:
> We are all caught up in the discussion on trail that we have ignored
> one of the most important things that Grant mentioned on his original
> posting. This is on the second paragraph:
>
> “So...the new sizes will fit a gigantic range of riders, all with four
> sizes.”
>
> This has more implications on us than the religious discussion on
> trail. By next year, we are going to be limited to four sizes for each
> model that RBW will come out. Now, are we going to be satisfied with
> that? This would mean that in order to fit on one of the four sizes,
> we will do so by use of various combinations of seat posts and/or
> stems.
>
> This method of fitting riders on limited numbers of sizes of bikes
> through use of seat posts and stems became the practice and espoused
> by Specialized [I think(?)] when it came out with its so-called
> “compact” framed bicycles [meaning sloping top tubes]. Some of us
> roadies learned to live with it others did not.
Giant pioneered that concept with a design by Mike Burrows.
Artie
customs made in USA, the current production models made by Toyo and
Waterford, and the singular model the Bleriot by Taiwan.
As the inventory of the Bleriots, which will be solely handled by RBW
by June, is exhausted, the new made-in-Taiwan models will come in. By
that time also, I hope RBW will continue to offer models made by Toyo
and Waterford. I said, I hope, for this depends on whether or not it
would still be profitable for RBW to do so, considering the continued
weakening of the US dollar versus the yen. Toyo might also be asking
for a minimum volume commitment from RBW. If RBW can meet this
minimum, we will still get Toyo-made Rivbikes. Otherwise, the Toyo-
made models will run out and we might find ourselves with more of
Taiwan-made and MUSA Riv bikes.
There is nothing wrong with this scenario. It is for the better.
Taiwan-made bikes are getting better. In fact the Bleriot is
beautiful. Had it come with a more graceful double taper seatstays, it
would have been perfect.
On May 20, 11:18 am, "Bill Connell" <bconn...@gmail.com> wrote:
CycloFiend
>
> I think a 3-tiered model offerngs exist right now from RBW. The
> customs made in USA, the current production models made by Toyo and
> Waterford, and the singular model the Bleriot by Taiwan.
>
> As the inventory of the Bleriots, which will be solely handled by RBW
> by June, is exhausted, the new made-in-Taiwan models will come in.
In his post, GP said that they would be coming in early '09. It did not
sound as if they would fold in so gracefully. I would expect a gap through
the winter. Also, the Bleriots are pretty much gone in the smaller sizes
right now.
> By
> that time also, I hope RBW will continue to offer models made by Toyo
> and Waterford. I said, I hope, for this depends on whether or not it
> would still be profitable for RBW to do so, considering the continued
> weakening of the US dollar versus the yen. Toyo might also be asking
> for a minimum volume commitment from RBW. If RBW can meet this
> minimum, we will still get Toyo-made Rivbikes. Otherwise, the Toyo-
> made models will run out and we might find ourselves with more of
> Taiwan-made and MUSA Riv bikes.
There's a lot of conjecture in that paragraph, and I'm not sure that
anything reinforces it. Nowhere has the topic of "minimum volume
commitment" come up, and I think that would be easy enough to overcome by
specifying it in the Reader or the RBW Blog. The retail prices have already
tipped upwards on the Toyo-built frames, and as GP wrote, they will be
shifting some of the builds to Waterford, with whom Rivendell has a long
relationship. It was made clear that the upward price movement was demanded
to keep them profitable.
I'd encourage you to check out the Toyo blog translation - (it's hard to
wade through, as the google-lation is choppy) Toyo seems very excited about
the RBW projects, but it's clear that their business has been growing and
they have had a _ton_ of their own projects.
- Jim
--
Jim Edgar
Cyclo...@earthlink.net
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-- Neal Stephenson, "Zodiac"
David Estes
I think a 3-tiered model offerngs exist right now from RBW. The
customs made in USA, the current production models made by Toyo and
Waterford, and the singular model the Bleriot by Taiwan.
--
Cheers,
David
Redlands, CA
jim g
> I think this observation also points out a couple of other
> considerations. Does a desired trail number in one tire size
> necessarily transfer directly to another tire size? Even if the outer
> tire diameter is identical, the pneumatic trail and handling will be
> different and might require a different geometric trail.
I recently re-read the article in Bicycle Quarterly Volume 5, Number
3, entitled "How to Design a Well-Handling Bicycle". In that article
(on page 45), two bicycles are discussed: Bike 4 has 700Cx30mm tires
(overall diameter 690mm) with 39mm of trail, and Bike 5 has 650Bx39mm
tires (overall diameter 669mm) with 26mm of trail. Quoting from the
text: "The wider tires of this 650B bike (No. 5) add significant
pneumatic trail, so the geometric trail has been reduced to 26mm. The
bike's handling is very similar to that of the 700C Randonneur bike
(No. 4)..."
So, that implies that trail should be reduced for a wider tire.
> Also, why
> wouldn't the desired trail for a mountain bike be different than that
> for a road bike?
The same article (on page 44) mentions: "Pneumatic trail is reduced on
unpaved surfaces, where the tire slip reduces the side forces
generated by the front tire. Therefore, bikes that are ridden
primarily on gravel or dirt should have slightly more geometric trail
to compensate for the reduced pneumatic trail."
-Jim G