Hi,
Just wondering if people could share their knowledge with me particularly Dan.
I am a 5"2,short legged Ironman and am having problems with my bike fit.
My new tri bike is a 47cm Kestrel Aerofoil Pro Dura ace.
I love this bike for its small design demensions and feel it is the best fit for me.
Except I am having problems at the top of the pedal stroke because feel I am too crunched up (knees are nearly hiting my ribs) due to my seat being too low,my seat height though is the correct length when my legs are at the bottom of the stroke.
Even though this may seem obvious,is the answer to change to a smaller sized pedal cranks,from 170mm supplied with the bike to 160mm,which is suggested in everything I have read and everyone I have talked to on the matter.
Also I have Oval tribars,are these the lowest tribars on the market,not sure if they are?.
Finally I am looking to get a training roadbike for my size with the lowest headtube height compared to the seat height,can anyone suggest any makes/models?.
Your help on these matters would be greatly appreciated.
Thanks
perhaps you could do well with adding some spacers under your stem. they’d bring you up a bit, but they’d probably stop your knees hitting your chest.
47cm comes stock with 650s, right?
edit: Litespeed has pretty low head-tubes stock, although if you’re willing to dish the cash, maybe custom would do you some good.
Thanks for that aerojunkie2,will look into adding some spacers.
what’s your view on changing my pedal cranks to 160mm’s,this would allow me to raise my saddle height by 10mm and also crucially I would then have an extra 20mm at the top of my stroke, this would be enough I think to solve the problem with the knees nearly hitting the chest?.
Know that I will lose some power as a result of the smaller cranks but would gain efficiency wise.
yeah my Kestrel has 650 wheels.
will look into litespeed as a roadbike
thanks
If you are short you should use a shorter length crank. Lennard Zinn of Zinn Cycles (www.Zinncycles.com) makes custom length cranks for hard to fit people. He uses a formula of inseam in millimeters multiplied by .21 to get the correct length.
160’ cranks aren’t a bad idea, as you said, you’d get the extra 10mm on the seat post, and would have added cornering clearence to boot.
you should be able to find 160mm cranks stock, without having to go custom, although if you do, Zinn is a great option.
cannondale optimo femine. Comes in a 40cmand 75degree seat angle.
thanks for the replies everyone,much appreciated
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My girlfriend is very short, just bumping up on 4'10". No tri bike for her (yet), but we've struggled to find good road bike solutions. Her first good ride was a Ti Wylder frame with 650s, shimano, and 170 cranks. Works okay, though not particularly fast. I found a Giant TCR aluminum in XXS (CF not available that small), and built it up with 700c, Campy (moving the entire lever to shift on the Shimano is tough for her small hands), and threw together a set of short cranks, just to see how they work for her. She absolutely loves the bike, and is demonstrably faster. Cranks she's using are cheapo 155mm "Bulletproof" brand, from a BMX shop, with a compact combo of Salsa rings. No shifting ramp on the outer, so shifting is not crisp. At any rate, I'd go with shorter cranks from somewhere, as your goal is basically to reduce hip angle without going higher up front. Is riding steeper an option for this with your current setup? Good luck.
“feel I am too crunched up (knees are nearly hiting my ribs) due to my seat being too low”
your seat may be too low, your cranks may be too long, your saddle may be too rearward, and your aerobars may be too low. those are all the reasons you may feel as you do. yes, i think shortening your cranks is a very good idea. but i couldn’t begin to troubleshoot the other issues unless i saw you aboard your bike. i would say that all things equal you probably have a good bike in a good size.
thanks very much Dan,I am going to look into all of this and already have 160mm cranks sourced.
I am also looking for a winter training bike to do those long slow miles,can you recommend anything,not looking for anything crazy expensive but still a bike that fits well enough my size,would it be worth looking at the female road bikes that some manufacturers make,is there much difference geometrically?
Thanks Dave,the shorter cranks should be the solution on my tri bike.
With regard to the training roadbike I am looking for,am tempted now to go for one of the female bikes made by most of the manufacturers,I looked at the technical specs on a few and there does not seem to be any major differences to a smallest male version (which don’t come small enough),except for maybe the seat which I would change.
Is there any reason that a small male can not go for a female road bike ?.