Riv Bike-Fit/Sizing Method Questions
jim g
bike-project. I want a "Rivendell fit" with bars about level with
saddle, and somewhere around "a fistful" of seatpost showing. I'm
about 5ft 10in tall; PBH is 86cm in bare feet, 87cm in my SPD bike
shoes; preferred crank length is 172.5 or 175mm. Saddle height on
current bike is comfortable at ~77cm.
I'm reading Riv's fit guidelines at
http://www.rivbike.com/article/bike_fit/choosing_a_frame_size and am
finding some confusing points. Starting from "How to Size any Bike,
Including Ours", they use an example PBH of 85cm, and suggest that a
corresponding saddle height is 75cm -- or 10cm less than the PBH. So
far, I'm OK with that: my saddle height is around 10cm less than my
PBH (especially accounting for my shoes).
Next Riv suggests that a good bike size is saddle height minus 15cm.
In my case, that's 86cm - 15cm = 61cm, or accounting for shoes, 87cm -
15cm = 62cm. Again, I'm in agreement with that: Most non-Riv 62cm
frames I've straddled have been a bit "snug" but not overly so in
standover height -- that is to say, the top tube touches but not
dangerously so. And I could definitely fit on a 60cm frame, but I'd
need a taller quill stem, or some extra spacers in a threadless setup,
and of course there'd be more seatpost showing.
Now, on to the next section on Riv's page: "Sizing Rivendells (the
bikes we design)".... If you look at the frame-size chart they
provide, for 86-87cm PBH measurements, they recommend 59-61cm frame
sizes! Here's where I'm confused -- most Riv frames have a lower BB
than a typical/average frame, up to 1cm lower. Most of Riv's sizing
theory says something like "you can straddle a bigger one-of-our-bikes
than one-of-theirs", so I've always thought that a correct Riv size
would be 1cm larger than a "typical" frame size (and by typical frame
I mean 1980's UJB steel frame or similar). Taking the previous frame
size result of 61-62cm, that'd put me on a 62-63cm Riv. HOWEVER that
chart points to a 59-61cm Riv frame for my body size -- which is
SMALLER than the first recommended "normal" size, and frankly sounds
too small!
For example, the 61cm AHH has an 8cm BB drop and standover is just
under 87cm -- that'd maybe be slightly too big for me (no clearance,
since it's the same as my shod PBH). I guess the "Riv Size = usual
size + 1cm" formula doesn't directly apply to the AHH because the
larger tires cancel out the added BB drop? The 59cm AHH frame has
85cm of standover, which seems about right (about an inch of PB/TT
clearance)...BUT a friend of mine rides this size, and he's always
been on shorter/smaller bikes than me...so a 59cm sounds too small
somehow.
In contrast, the 61cm Atlantis has a standover of 85cm, so that'd fit
me with the right clearance. Why that frame would fit but the
same-size AHH wouldn't, isn't clear to me -- looking at their
geometries, both have the same BB drop, similar size tires, the same
seat-tube angle, and both have slightly-sloping top tubes.
The Legolas frame is more typical since it has a standard 70mm BB
drop. (Ignoring the fact that it's intended as a CX bike, which might
indicate more-than-usual SO clearance) I could ride a 62cm size since
its standover is 86.2, but clearance might be tight. The next smaller
size is 59cm with 84.3cm standover.
The Quickbeam frame is also fairly "normal" with a 73mm BB drop. The
62cm frame size has a standover of nearly 87cm (too big), but the 60cm
size's SO is about 85cm.
Now let's compare those data points with a fairly typical non-Riv
steel frame: A Surly Pacer (level top tube, 72.5-degree seat tube
angle, 72mm BB drop). The 62cm frame size has a standover measurement
of just under 86cm, and the 60cm size's SO is 84cm (based on 700x25mm
tires). Riv's Rambouillet frame has similar values at the same sizes.
Overall, it sounds like I could ride a bigger Pacer frame than most
Rivendell frames -- which seems utterly counter-intuitive to me, since
most Riv frames have lower BBs!
If anyone has a PBH of 86-87cm, I'd be very interested to hear what
size frame(s) you've chosen (both Riv and non-Riv) and why.
Thanks!
-Jim G
Ron Farnsworth
| I'm about your size and couldn't decide between a 59 or 61 AHH and ended up getting the 61 after talking to Grant. In hindsight I probably could have ridden either one. On my frame with the bars about the same height with the seat, the Nitto Tech Deluxe handlebar stem is at max height and the Nitto seat stem is not at max height which sounds about like what you mention you want in your message. Standover height clearance is a bit more snug than I'm used to but is easily acceptable and now I am used to it, no problem. The bike is very laid out and comfortable and rides very smooth with Jack Brown Greens and performance wise moves around quicker than I thought it would. Hope this helps. Ron F. in MA --- On Thu, 4/16/09, jim g <yoj...@gmail.com> wrote: |
Seth Vidal
>
> I'm trying to figure out the right frame size for a possible next
> bike-project. I want a "Rivendell fit" with bars about level with
> saddle, and somewhere around "a fistful" of seatpost showing. I'm
> about 5ft 10in tall; PBH is 86cm in bare feet, 87cm in my SPD bike
> shoes; preferred crank length is 172.5 or 175mm. Saddle height on
> current bike is comfortable at ~77cm.
I'm a little taller than you but I have close to the same pbh.
I bought a 58cm atlantis. I'm pretty sure I could ride a 61cm atlantis
however, I've noticed that the size of tires I have on it raise the
standover a fair bit. I've have 42mm tires and I think if the size of
the frame went up even as little as 3cm I'd be a little less
comfortable when I had to stop and standover it.
Not terrible, but a little dodgy.
Maybe I just have short legs.
Unfortunately, where I tested out the bike there was no 61cm available
or I would have tested it specifically.
-sv
PATRICK MOORE
A stock 60 would have a longer tt than I care for -- I like 56-57 effective and I would guess that a 60 would have about a 59 cm tt -- but then I like my bars low. If your arms are Anglo in length like your legs, and you want your bars level with saddle, a 59-60 cm tt might be fine.
Patrick Moore
Albuquerque, NM
Professional Resumes. Contact resumesp...@gmail.com
Angus
I've got an 89cm pubic bone height and 79cm saddle height. I have
three 64cm Rivendell's. I have no crotch to top tube clearance on any
of them...it's not a problem.
This is actually a bit bigger than RBW sizing suggests.
I'd probably be OK on a 62 as well.
Angus
On Apr 16, 1:49 pm, jim g <yoj...@gmail.com> wrote:
> I'm trying to figure out the right frame size for a possible next
> bike-project. I want a "Rivendell fit" with bars about level with
> saddle, and somewhere around "a fistful" of seatpost showing. I'm
> about 5ft 10in tall; PBH is 86cm in bare feet, 87cm in my SPD bike
> shoes; preferred crank length is 172.5 or 175mm. Saddle height on
> current bike is comfortable at ~77cm.
>
Esteban
You've documented some of the specifics - and perhaps contradictions -
of Riv sizing. Some of it depends. I've seen folks ride an Atlantis
a size smaller because they want a lower top tube to straddle on fully
loaded tours.
I'm an 88 pbh, and ride both my 62cm 650B Protovelo and 62cm Quickbeam
comfortably. The Protovelo is perrrrrfect. The Quickbeam, with its
700c wheels, is at the upper limit of stand-over height for me - like
*really* up there. Thing is, it rides like a dream - amazing comfort
on the saddle for long periods of time. Pedal strokes feel big, in a
good way. When looking for a Ram/Rom, I was aiming for a 60cm which
would give me a little more breathing room and a compactness for
harder riding. I found a well-cared for 59cm Romulus, was worried it
was too small, but it fits great for how I ride it - with more than a
fistfull of seatpost. I'd prefer a 60...but I wasn't choosing among
new bikes.
I'd do measurements without shoes. Pull all the way up with that
ruler and, as they say, record the highest price. Then think about
the frame - touring, road, off-road, etc. A centimeter bigger or
smaller might be fine.
Esteban
San Diego, Calif.
Doug Peterson
When I bought my Atlantis, Riv suggested I go with 61 and I was confident a
58 would fit. 6 years later, I'm perfectly happy with the 58, with 10 cm
Nitto stem and 175 Sugino cranks. I've had various UJBs, Treks, etc. from
56 to 58 and been fine.
I pulled my file and Riv had an Atlantis flyer with some sizing charts.
There's some overlap in frame sizes. A 58 is listed for PBH 84 to 89 and
saddle ht of 74 to 79. The 61 is for PBH of 87 to 93 and saddle at 77 to
82. On my build sheets I listed PBH at 86 and saddle at 76 (that was on a
UJB) and I'm 5'11" tall. So I'm slightly taller with my saddle slightly
lower than you.
Since the largest frame I'd lived with was a 58, I was a bit surprised when
Riv suggested 61. The sizing chart put me on a 58. The bike came with 35
mm Pasela tires and it's now on 35 mm Schwalbes which are a bit plumper but
I still have adequate stand over clearance with both feet on the ground.
The h'bars (Nitto drops) are up even with the saddle.
Stem is the 10 cm that came stock. I would drop down to 170 cranks were I
to do it again as the 175s limit clearance off road. 5 mm isn't much extra
clearance so it's a minor issue. I didn't think thru the BB height issue,
just order what I'd been using, my bad.
Hope this helps. Assuming your comfortable with your current fit, the key
is figuring out how to duplicate that fit on another bike. Fortunately,
you're in middle of sizing bell curve so you've got plenty of room to work
in.
dougP
-----Original Message-----
From: rbw-owne...@googlegroups.com
[mailto:rbw-owne...@googlegroups.com] On Behalf Of jim g
Sent: Thursday, April 16, 2009 11:50 AM
To: rbw-owne...@googlegroups.com
Subject: [RBW] Riv Bike-Fit/Sizing Method Questions
Esteban
charlie
Trucker which is similar to an Atlantis and I chose a 58cm. I use
175mm arms now and ride with Crank Bros. 50/50 pedals and Tevas
mostly, skate shoes or my Redwing boots. I have a shorter reach than
most and I use a 90 mm stem length. I could probably ride a 60 or 61
Riv frame depending on the model and the tire size. I use Schwalbe
700x47's on my Trucker so the 58 cm works nicely for me. I think your
saddle height indicates a 59-61 being right in the ballpark. I think
you might be making it a little too complicated. Its only 2 cm
difference or 20 mm which is less than 3/4 of an inch. In my mind if
you can stand over a given frame size with your tire preference and
you can get the bars where you want them then that is what you are
looking for. You should be able to get your bars high enough with
either size all the way from 58-61. You just might need to use a Dirt
Drop stem with the smaller sizes but they are stronger anyway
so...........it sounds like you know what works. Other bikes with
higher bottom brackets and skinnier tires aren't a good comparison and
serve to cloud up the subject (unless you want one of them) I think
you just need to look at the standover and the bar height and distance
to the bars regardless of the frame style/brand and just use your
measurements to get you wherever you want to be. More post, less post,
long stem, short stem, these are just aesthetics when you get right
down to it since there is easy adjustment built into quill stem
bicycle frames. I think you just want to avoid the extremes. For
instance riding a 55 cm or a 67 cm.
On Apr 16, 11:49 am, jim g <yoj...@gmail.com> wrote:
> I'm trying to figure out the right frame size for a possible next
> bike-project. I want a "Rivendell fit" with bars about level with
> saddle, and somewhere around "a fistful" of seatpost showing. I'm
> about 5ft 10in tall; PBH is 86cm in bare feet, 87cm in my SPD bike
> shoes; preferred crank length is 172.5 or 175mm. Saddle height on
> current bike is comfortable at ~77cm.
>
jim g
On Apr 16, 5:06 pm, charlie <charles_v...@hotmail.com> wrote:
> I am 5'11' and I have a 86.4 cm PBH. I currently ride a Long Haul
> Trucker which is similar to an Atlantis and I chose a 58cm. I use
> 175mm arms now and ride with Crank Bros. 50/50 pedals and Tevas
> mostly, skate shoes or my Redwing boots. I have a shorter reach than
> most and I use a 90 mm stem length. I could probably ride a 60 or 61
> Riv frame depending on the model and the tire size. I use Schwalbe
> 700x47's on my Trucker so the 58 cm works nicely for me.
bet you have a decent amount of seat post sticking out?
I agree that I am over-analyzing this and that it is, to a large
degree, a question of (certain) aesthetics...but I am trying to
understand the subtleties. There are other factors at play too, such
as head tube length, which can impact max handlebar height. For
example, I have 4 frames all nearly the same size (ranging from
57-58cm), yet they all have different head tube lengths. Fork-blade
length affects this, too.
Ultimately, I currently have a 57.5cm RB-1 that I either need to use a
long Technomic on to get the bars where I want 'em now, or I need to
replace it -- and if the latter, I'm wondering if I should go with a
60cm or 62cm frame.
-Jim G
charlie
but on a Riv you'd get maybe an inch and a half more due to the
absence of the clamp. The measurement is from the top of the clamp to
the bottom of the curve of a S83 post. I left my steer tube uncut so
that gives me a noodle bar that is around 1.5 inches higher than the
saddle with my 105 degree stem. The Trucker has a similar extension of
the head tube like an Atlantis but not reinforced with a lug etc. I
like the look of a short seat post that gives a bicycle that
"frenchy" look rather than the mile high seat post with bars so low
your spine is forced into a reverse S shape. I do however enjoy enough
room over the top tube to go off road on uneven ground and not get a
bruised crotch. I realize this effect is often over exaggerated by
many but still, I like about an inch of clearance from the actual
pelvic bone. I know what you mean about different frame sizes, head
tubes and rakes etc. I have 57,58 and 58.5 cm frames and they are all
different. I'm even noticing the difference in how they handle. These
days I prefer the longer wheelbase slack angled touring frame with fat
tires. There is no more comfortable bike. In fact, my recumbent (on
rough roads) is not as comfortable. You might in fact be suited to a
61 cm frame. It may be that you have long enough arms/torso to make up
for the longer top tube and you won't need too short of a stem to find
the sweet spot.
EricP
wanted to be able to straddle the bike comfortably with Schwalbe Big
Apple 50s. Might have been able to do that with a 61. But then the
reach gets a bit long. On two other bikes (Surly Cross Check and
Kogswell P/R) went with the bigger size and ended up not being able to
run drop bars. Have tried it repeatedly. Always end up with hand
issues that don't go away quickly. In this case, it's a tradeoff
between comfort and looks.
Straddled a 62cm Quickbeam last year. For my build, there was "no"
clearance. Just seemed huge. Yet a 61cm Bleriot doesn't feel large.
Eric Platt
St. Paul, MN
>
> - Show quoted text -
David
center to top, and I run the bars even with the saddle, give or take a
little. I also ride a De Rosa that is 59 center to center, probably a
60.4 center to top. Getting the bars even with the saddle requires a
technomic (non deluxe) with lots of extension on the De Rosa. The
Romulus fits perfectly. I thought about getting a 59 Romulus, but
Rivendell said get the 61, and I'm glad I listened. With a Technomic
Deluxe, I can get the bars well above the saddle if I want. I have
about an inch of standover clearance. Comparing Riv frames to
"standard" frames is a bit complicated in that you are dealing with bb
drop, upsloping top tube, and an extended head tube. My take on the
sizing range factor (especially with the Atlantis) is choose a smaller
frame when using way fat tires to maintain standover.
> bike-project. I want a "Rivendell fit" with bars about level with
> saddle, and somewhere around "a fistful" of seatpost showing. I'm
> about 5ft 10in tall; PBH is 86cm in bare feet, 87cm in my SPD bike
> shoes; preferred crank length is 172.5 or 175mm. Saddle height on
> current bike is comfortable at ~77cm.
>
Pete Ruckelshaus
Rambouillet, but 58's are rare as hen's teeth on the used market, so I
bought a used 60cm. I love the frame, but it really feels too big for
me...I raced in my youth, and have always felt that 58cm frames
usually fit about right, but this 60cm has me feeling like I'm riding
the high wire...to the point where I'm seriously considering selling
the 60cm Ram frame and going back to my old (58cm Specialized Allez
steel) frame (I'd prefer to find a 58cm Ram, though, so I can continue
to run wider tires). I guess part of me also disagrees with Grant's
bigger frame = better philosophy, so take that with a grain of salt.
However, if I were in your shoes, I'd go for the smaller size in the
recommended size range.
Pete
Bill Connell
>
> I'm in the camp of riding a size (or 2) smaller Atlantis because I
> wanted to be able to straddle the bike comfortably with Schwalbe Big
> Apple 50s. Might have been able to do that with a 61. But then the
> reach gets a bit long. On two other bikes (Surly Cross Check and
> Kogswell P/R) went with the bigger size and ended up not being able to
> run drop bars. Have tried it repeatedly. Always end up with hand
> issues that don't go away quickly. In this case, it's a tradeoff
> between comfort and looks.
>
> Straddled a 62cm Quickbeam last year. For my build, there was "no"
> clearance. Just seemed huge. Yet a 61cm Bleriot doesn't feel large.
Doesn't the Bleriot have most TT slope than the QB?
I've found that the big road bike works well for me, even though i
don't have my bars above the saddle (they're pretty much level). It IS
a different feel; most stately in a way than a more typically-sized
smallish road bike. I'd size like that for racing crits, but not for
general road riding. On the other hand, i agree with going down a size
or so for off-road use, and it's important to consider the largest
tires you'd want to use before deciding frame size.
--
Bill Connell
St. Paul, MN
Doug Peterson
tough to shrink them.