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Hi Xeney - So here's my challenge to you and others.Quote:
Originally Posted by xeney
One could definitely make a bike that would fit a women with a long femur and short torso, but likely it wouldn't be 700C wheels. Would a smaller size set of wheels (26", or even 24") be a deterrent?
I have heard repeatedly that there is a general bias against road bikes with wheel sizes other than 700C, and that bias is the driver behind a lot of poor bike designs in my opinion.
Surly 52 cm Cross Check.
Brooks B67 slid back as far as it will go. Approx 5 cm seat post out.
Dimension 120 degree stem on the standard cut steerer tube. (3 0.5cm spacers) Moustache bars with the bar ends at just about even vertically with the steerer. Top of bar (top of stem) nearly even horizontally with top of saddle.
I tend to prefer 175mm cranks due to my preference for mashing, and my femur length and difficulty getting a good KOPS. BTW, don't discount KOPS/Pat-to-Met just cuz some whippersnapper wrote an article "disproving" it. If you read what he has to say, it actually boils down to KOPS/Pat-to-Met. I got pretty grumpy after reading that article...
If I get a Buena Vista I would either have moustache bars or Nitto All-Rounder bars put on it. The All-Rounders would certainly shorten the cockpit. I like both these bars on my bikes that have them. (My 1987 Giant RS940 has All-Rounders. I'd like to convert her to 650b wheels, she'd be perfect for that with her low brake bridge and fork. If I do that, I'll also have her powdercoated, which means spending enough money in all that I really can't afford a Buena Vista. :eek:)
If you have the time and interest to compare fits of the CC vs. the BV, go for it! I'd be interested in seeing what you come up with. There are other Surly riders who also might be interested. (but I really shouldn't buy another bike right now... but it'd be interesting to see how they compare... oh, but I *really* shouldn't buy another bike right now)
FurryBlue - I think you did a very good job of explaining the effect of seat tube angle on cockpit length and how it plays into reach. I also liked the way that you explained how top tube length is important as it affects (with the head tube angle) toe overlap. But all in all, top tube length is a huge component of reach and the concerns these women have about the reach of these frames seems justified.
I'm learning a ton about frame geometry from reading this discussion!
FurryBlue -- re: your question about wheel size bias. (For background, I'm 5'1", short torso) When I was looking for my first road bike (maybe 15 years ago?) I wouldn't have known that I ought to be biased towards 700c wheels, but a small amount of research informed me about toe overlap being an issue with what was "standard" for road bikes, and I also had learned of Terry's approach to using a smaller front wheel. I was a poor student and couldn't afford a Terry, so I was basically discouraged from road bikes and spent my money on a mountain bike that became my all-purpose workhorse.
I started looking for a road bike again a couple of years ago, and this time I picked up a used touring bike outfitted with 650c wheels. I wasn't even interested in wheel size when I went for a test ride. All I knew was the bike felt incredible, and I was in love.
When I lost that bike and started looking for a replacement, all I could find (maybe I was looking at the wrong time of year?) were bikes with 700c wheels. And they all felt high to me, center-of-gravity-wise as well as difficult to step over (I have a bad hip). Long story short: the replacement bike has 650c wheels.
Maybe with the right frame design I might be comfortable on a bike outfitted with 700c wheels, but in my opinion the industry bias towards this wheel size generally makes it more difficult and more expensive for someone my size to find a bike that fits.
I'm sure some riders have their reasons for insisting on 700c wheels. I know that there are women about my height who use 700c, and I'm sure that setup makes sense for them based on the type of riding they do, skill level, etc.
Speaking just for myself, a smaller wheel size would NOT be a deterrent. I also commute on a folding bike with 20" wheels.
I've also never been picked to participate in a focus group, I think because researchers pick up pretty quickly that I'm not in sync with whatever plays well in Peoria . . .
Wheel size would not be a deterrent for me, either, but that seems a little irrelevant to this discussion given that they made the Buena Vista to work with 650B wheels. If they were doing that already I don't think it was wheel size that caused them to make the effective top tube so long and the seat tube angles so steep. I think they were just interested in building a men's mixte.
I had my custom Luna made with a slacker seat tube angle because on my other bike my weight was sort of balanced right on top of the crank, like a unicycle effect. I felt my weight too far forward onto my hands, and could not 'get behind' my pedaling. When you feel your weight falling forward most people just label it too long a reach, but I found it all works together- head tube angle, seat tube angle, top tube length, etc......to either make you comfortable or uncomfortable. Weight balance is a big part of the whole reach issue.
On my Luna, even though the reach is pretty similar to my older bike, the seat is further back from the crank and I no longer feel like my hands have to keep me from falling forward. Now my legs do that automatically. Thus, it no longer feels like the reach is too long. :)
Wonderful - I'll work up some numbers later.Quote:
Originally Posted by KnottedYet
Thanks Wahine. I don't mean to discount the concerns of those for whom the BV mixte may be a poor fit. I did want to point out that comparing fit between bikes strictly from top tube length alone is inadequate.Quote:
Originally Posted by Wahine
Designing stock bikes that are not intended to fit a specific person is kind of tricky. As has been pointed out in various discussions, many women fit the long legs, short torso model, but some don't.
This discussion started out with comments on the BV saying "what were they (BV designers) thinking" and my point is that I can well imagine what they were thinking - they were thinking about a small range of sizes based on 700C wheels and one size with 26" wheels, and the BV geometries are roughly what one would come up with given those parameters.
I agree though that to better design some stock sizes specificially for women who have long legs/short torso I would do the following: i) use slacker seat tube angles, ii) have several sizes using smaller wheels.
Hi Xeney, you know, at first the SOMA blog said something about 650B compatibility, but I'm skeptical.Quote:
Originally Posted by xeney
Rivendell's Saluki and Bleriot are 650B specific and have a 67 mm bottom bracket drop, and that ends up being quite a low bottom bracket height. The issue with a low bottom bracket is more tendency to scrape the pedals on the ground when pedaling through corners.
The BV geometry says the bottom bracket drop is 74 mm, that is even lower than the Riv 650B specific designs which some complained were too low. So I guess you could put 650B wheels on the bike, but I don't think it's a good idea.
Great comments. The Luna bikes look really nice to me.Quote:
Originally Posted by BleeckerSt_Girl
Thanks for your comments Jocelyn.Quote:
Originally Posted by jocelynlf
For my riding style the issue with 650c is most of the available tires are narrower than I like, and the mountain bike 26" tires tend to be heavy. But fit wise, I think those wheels are the way to go for many shorter people.
http://www.terrybicycles.com/movies.html
Georgena Terry has some really swell videos here that illustrate her frame design choices....might add to the conversation....
(also her video on cleaning and lubing was helpful for me)
Love her videos. I feel like I'm sitting at her table drinking a glass of iced tea while she explains stuff to me.
Hi KnottedYet, Sorry for the delay in this response.Quote:
Originally Posted by KnottedYet
I hope this is not to much detail, I'm going to compare two sizes of the Surly Cross Check with the small size Buena Vista. I used the BikeCAD applet and some educated guesses to come up with the numbers.
Let me start with the 52 cm Cross Check. I calculate it has a front center of 590 mm. I believe that is about as short a front center as is really desirable for medium width (say 700 X 35C) wheels. To "normalize" the reach, I calculate that if the seat tube angle of the 52 cm Cross Check was changed to 73 degrees, then the effective top tube length (giving the same front center) would be 551.9 mm.
By the way, it's just a guess, but looking at the drawing and with a 110 X 120 degree stem, I'm guessing your saddle height is about 680 mm which sounds a little low for someone who is 5' 8"
Now let's consider the 50 cm Cross Check before moving on to the Buena Vista. It has a 542 effective top tube with a 74 degree seat angle which yields a front center of 589.3 mm. Notice the front center has only changed about 0.7 mm, and if we "normalize" to a seat tube angle of 73 degrees then the effective top tube is 551.2 mm, only .7 mm change. So as far as reach to the bars and front center goes, the 52 cm and 50 cm Cross Check are virtually the same. The reason is the design is hitting the constraints of the 700C wheel size.
Finally, let's go to the 50 cm Buena Vista. I calculate it has a 583.0 mm front center which is a little short in my opinion for the larger 700 C tires, and an effective top tube length (normalized to a 73 degree seat tube angle) of 545.5 mm, so 6.4 mm less than the 52 cm Cross Check - that's like a quarter of an inch, so we are talking small differences here. Now, the Buena Vista also has a longer head tube, so even though the frame is a smaller size (50 cm BV versus 52 cm CC), it is easier to get the handlebars up high. I calculate that you (KnottedYet) would achieve the same reach the to the handlebars and same handlebar height with the 50cm BV by switching to a 100 mm X 0 degree stem and eliminating 5 mm of spacers.
By the way, a fun and useful tool for stems and so on is here:
http://alex.phred.org/stemchart/Default.aspx
In conclusion, the 50 cm Buena Vista would fit KnottedYet about as well as the CrossCheck just in terms of reach to the handlebars - the effective horizontal reach is about a quarter inch less but head tube is taller so it's easy to get the bars higher and so the stem changes to a flatter and shorter one.
The Buena Vista has a nice low bottom bracket which I think is better for a road bike (the Cross Check is a bit high at 66 mm compared with 74 mm for the Buena Vista). However, there are some aspects of the Buena Vista geometry that are less desirable than the CrossCheck if we assume the CrossCheck is a good fit for KnottedYet:
i) the Buena Vista has a steeper seat tube angle and so you would need about another cm of setback in your seatpost to achieve the same saddle/crank relative position. Since you state you are already all the way back on the rails with your current seatpost, you would need a different seatpost.
ii) toe overlap will be somewhat increased and if you want to run larger tires and or fenders you might be less happy than with the CrossCheck
iii) although both the BV and the CC have the same head tube angle and the same fork rake, the handling will be a little different because of the weight balance and wheelbase: the BV has a shorter front center (puts more weight over the front wheel), and a longer rear center (also puts more weight over the front wheel), so if the Cross Check feels properly balanced then the Buena Vista won't feel as balanced. The balance issue will be more pronounced if you stick with your current seatpost and position your entire body more forward with respect to the cranks.
Xeney...look at this pic. Is this the new one or has Soma made these in the past?