Grant sent along another update which touches on a whole heap of subjects. 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!
Thanks for posting this. 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!
On Fri, May 16, 2008 at 9:29 AM, Ryan Watson <rswat...@nyx.net> wrote:
> Thanks for posting this. > 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.
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," > > 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.
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.
I myself like sloping TT. Besides having short legs, a sloping TT can
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.
On May 16, 7:47 am, CycloFiend <cyclofi...@earthlink.net> wrote:
> Grant sent along another update which touches on a whole heap of subjects.
> 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!
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.
> > 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...
-Doug Shaker Expert Support Inc. mailto:dsha...@xs.com 201 San Antonio Circle, #102 voice: 1-650-739-0844 Mountain View, CA 94040-1234 fax: 1-650-739-0814
On Fri, May 16, 2008 at 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. 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.
These days, to me, a nicely detailed bike that forces on you a low bar
and
skinny tires. SENTENCE SHOULDN'T END THERE. MEANT TO ADD...
"....looks ridiculous." Sometimes a NICE ridiculous, but still...
Grant
On 5/16/08, gr...@rivbike.com <Grantmill...@gmail.com> wrote:
> These days, to me, a nicely detailed bike that forces on you a low bar > and > skinny tires. SENTENCE SHOULDN'T END THERE. MEANT TO ADD... > "....looks ridiculous." Sometimes a NICE ridiculous, but still... > Grant
Hey Grant! Design the Bombadil or whatever else according to your seat of pants sense of truth, justice and the American Way! Don't let the analyzers bother you.
I think tho' that there are big differences in how tires feel (tho' I cannot prove that nice feeling tires *are*faster). I ride skinny, 21 mm Turbos on 559, skinny (19 mm outside) semi aero rims on my '99 Joe and '03 Curt, and they feel fine, as smooth as the 28 mm (actual) Pasels on my light 531 Motobecane, and this over rough pavement, too. Extreme case: I had an old Nishik mtb with tire and tube combo that allowed me to ride, literally, through a briar patch (goadhead carpet), leaving me with literally dozens of the little bastards to brush off the tires afterward; no air loss *at all*. Now these tires/ tubes made riding feel as if I were riding against a stiff headwind up a hill.
Related to tires: My 3 custom Rivs have been far, far stiffer than many other bikes I've owned -- I could carry 40 lb of groceries on my erstwhile '95 Waterford custom with nary a sway and in perfect control -- but they *ride smoothly*, more so than many other bikes I've ridden, and these even with much fatter tires. Long stays? What gives?
Lastly, as to wind resistance: with our strong winds (I often head home into NWS "25 mph gusts to 35") I personally very much need a low aero position, even if my average at the end is no more than 15 mph.
Patrick "have a wonderful, permanent, Christian polygamous marriage with my two custom 26" wheel Riv fixeds" Moore
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:
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. 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.)
On May 16, 10:47 am, CycloFiend <cyclofi...@earthlink.net> wrote:
> Grant sent along another update which touches on a whole heap of subjects.
> 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!
> 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.
On Fri, May 16, 2008 at 10:13 PM, Tim McNamara <tim...@bitstream.net> wrote:
> 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.
>> 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.
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.
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?
on 5/17/08 10:56 AM, Doug Shaker at d...@theshakers.org wrote:
> 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.
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.
On Sat, May 17, 2008 at 3:33 PM, CycloFiend <cyclofi...@earthlink.net> wrote:
> on 5/17/08 10:56 AM, Doug Shaker at d...@theshakers.org wrote:
>> 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.
> "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"
-- How often I have lain beneath rain on a strange roof, thinking of home.
Except the line on the ground can be arrived at in different ways. I think 40mm of trail with a 74 degree headtube will handle differently than 40mm with a 72 headtube.
On Sat, May 17, 2008 at 1:49 PM, Michael Wise <mishaw...@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.
> On Sat, May 17, 2008 at 3:33 PM, CycloFiend <cyclofi...@earthlink.net> > wrote:
> > on 5/17/08 10:56 AM, Doug Shaker at d...@theshakers.org wrote:
> >> 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.
> > "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"
> -- > How often I have lain beneath rain on a strange roof, thinking of home.
on 5/17/08 2:49 PM, Michael Wise at mishaw...@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 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.
On Sat, May 17, 2008 at 5:56 PM, CycloFiend <cyclofi...@earthlink.net> wrote: > 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.
> 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.
Keep in mind just looking at trail will not give you the complete
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.
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.
On Sat, May 17, 2008 at 4:49 PM, Philip Williamson
<philip.william...@gmail.com> wrote: > Except the line on the ground can be arrived at in different ways. > I think 40mm of trail with a 74 degree headtube will handle differently than > 40mm with a 72 headtube.
> How differently? No idea. > Philip
> On Sat, May 17, 2008 at 1:49 PM, Michael Wise <mishaw...@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.
>> On Sat, May 17, 2008 at 3:33 PM, CycloFiend <cyclofi...@earthlink.net> >> wrote:
>> > on 5/17/08 10:56 AM, Doug Shaker at d...@theshakers.org wrote:
>> >> 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 >> > Cyclofi...@earthlink.net
>> > "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"
>> -- >> How often I have lain beneath rain on a strange roof, thinking of home.
-- How often I have lain beneath rain on a strange roof, thinking of home.
On Sat, May 17, 2008 at 4:56 PM, CycloFiend <cyclofi...@earthlink.net> wrote:
> on 5/17/08 2:49 PM, Michael Wise at mishaw...@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.
-- How often I have lain beneath rain on a strange roof, thinking of home.
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