Clydesdales/Athenas (200+ lb / 91+ kg) - Bike fit remediation

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View Full Version : Bike fit remediation


tony_merlino
03-19-12, 09:26 AM
I recently pulled my old road bike out of mothballs (where it was for almost 14 years) and started riding it again. It's funny - I rode that bike for many thousands of miles back in the day, and it never bothered me all that much. But even back then, people used to say that I looked a little "scrunched" on it.

Last week I took it out, and DID feel scrunched. I have the seat back as far as it can go, and my legs fit the bike pretty well. But the seat to handlebar distance seems too short now (maybe I'm just used to my other bikes...).

I've always had the problem that my legs are shortish for my torso, so a bike that lets me stand over the bar comfortably will probably wind up being short in the top-tube. But I probably could have gone up 2 cm in the size without imperiling the boys overmuch, and the bike would have fit better overall.

But I own this bike, and would like to see if I could make it fit better. Would a set-back seatpost + maybe a longer stem do the trick? Or is riding a frame that's about 1" too small such a bad idea that I should try to sell the bike (I'd hate to have to do that - this bike has a lot of sentimental value for me) and get a bigger one?

Thanks!


CACycling
03-19-12, 09:44 AM
The seat setback isn't where you should be adjusting a too-short top tube. Get the saddle set so your knee is roughly over the pedal spindle when you are seated on the saddle and the crank arm is pointed straight forward. Then work on reach with a longer stem. Depending on how much you need to make up, you might be able to get this bike to work.

Yo Spiff
03-19-12, 09:59 AM
I also have stumpy legs with more of my height in my upper body. I ride a 51cm (traditional style steel) frame in order to get good reach to the bars. I had a 48cm road frame at one time, but no matter how long a stem I put on it, it didn't feel right. So my standover height is just a little taller than the rule of thumb, with a little less seatpost showing than for most folks.


tony_merlino
03-19-12, 10:04 AM
I also have stumpy legs with more of my height in my upper body. I ride a 51cm (traditional style steel) frame in order to get good reach to the bars. I had a 48cm road frame at one time, but no matter how long a stem I put on it, it didn't feel right. So my standover height is just a little taller than the rule of thumb, with a little less seatpost showing than for most folks.This bike is a 51; I probably should have bought a 53 or 54. I've got about 3" of seat post showing.

I think I'm going to spring for a professional fit, and suspect that a new stem will come out of it. My main concern is that the handling will change a lot.

TrojanHorse
03-19-12, 10:14 AM
I don't think changing the stem will affect your handling as much as you think - except for your own position on the bike. I went from a 140 to a 120 on my old bike (which was still too long) and it wasn't bad at all. Granted, 20mm is pretty small, but stems are cheap enough that you can try it and see what you think before going to a fitting.

jethro56
03-19-12, 10:25 AM
I went from a 110 to a 90 and the first few times it felt squirrelly. Now I don't even notice. Your 51 probably has a 90 on it so you could go clear up to a 130. If you visualize the handlebar from overhead adding a longer stem doesn't change the radius all that much. Wider bars probably changes it more. For me trying the shorter stem was only $50. A fitting is $150 and then I'd buy one of their $100 stems.

tony_merlino
03-19-12, 10:31 AM
Silly question, but where do you measure the stem from? I'd like to figure out what I have, so I can order something longer.

TrojanHorse
03-19-12, 10:36 AM
I don't think it's silly but I believe it's center to center - so center of the fork post to center of the handlebars. It's probably marked right on the stem somewhere anyway. Do you have a quill stem or a newer stem that clamps on to the fork steerer tube?

jethro56
03-19-12, 10:50 AM
center to center. Another consideration is angle. I went from a 110mm 7 degree to a 90mm 8 degree to keep the height nearly the same. Take a look at the saddle height to handlebar position on a bike that fits well and consider that. I'd suspect that a larger bike has less drop as the seatpost isn't as extended.

tony_merlino
03-19-12, 10:52 AM
I don't think it's silly but I believe it's center to center - so center of the fork post to center of the handlebars. It's probably marked right on the stem somewhere anyway. Do you have a quill stem or a newer stem that clamps on to the fork steerer tube?It's a quill stem, and measured center-to-center, it's 90mm. So it sounds like I could add about 1.5" to that...

jethro56
03-19-12, 10:58 AM
My last post isn't relevant then.

TrojanHorse
03-19-12, 01:46 PM
Quills are harder to find nowadays... you can buy adaptors though, so a quill that ends in a fake fork tube so you can use modern stems / handlebars (but then you'd need new handlebars too.)

You should be able to find something though, they're out there... especially on the internet.

Heres what I mean by adaptor: If the link doesn't work, just google "quill stem adaptor"
http://www.google.com/products/catalog?q=quill+stem+adaptor&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&um=1&ie=UTF-8&tbm=shop&cid=17284772046554871264&sa=X&ei=anVnT-uVF4e6iwLlxcmlBw&ved=0CC4Q8wIwAQ

squirtdad
03-19-12, 03:27 PM
quill stems

http://www.rivbike.com/Nitto-Stems-s/108.htm