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  #1  
Old 11-24-2020, 07:39 AM
HiddenShadow20 HiddenShadow20 is offline
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Leg length discrepancy of 3/4-1 inch

Hello,
Due to a deformity of my pelvis I have a leg length discrepancy of between 3/4” and 1 inch.
I compensate by wearing a half inch lift in my walking shoes. I have them altered at a cobbler.
I do like to ride my road bike but I get some discomfort in my lower back after about an hour of riding. My road shoes are unaltered.
I’m wondering what I can do to make up for this discrepancy.
I run a 1/4 inch shim on my shorter leg and have the cleat all the way forward on that foot.
On the longer leg I have the cleat all the way back. I run 172.5mm shimano cranks on a 54cm frame.
I’d like to run a 1/2 inch shim but I can’t find screws that long. I run look keo cleats and pedals.
My setup doesn’t work that well, so I’d appreciate anyone else’s input on what to do.
Thank you.
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  #2  
Old 11-24-2020, 09:13 AM
jojobos jojobos is online now
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You need to double check but it looks like the orginal Look keo bolts are M5-0.8 10mm. For using 10/15/20mm spacers, you can use M5-0.8 20/25/30mm perhaps??
https://www.amazon.com/dp/B083Y26PR3...ding=UTF8&th=1

Also check it out
https://www.stevehoggbikefitting.com...rt-3-shimming/

Last edited by jojobos; 11-24-2020 at 09:19 AM.
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  #3  
Old 12-05-2020, 04:13 PM
NeauDL NeauDL is offline
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You'll probably need multiple approaches to compensate for such a large leg length discrepancy. I try to compensate about 8 mm because of a shorter left leg. I use an extra 3 mm thick insole in the left shoe. I also have a 5 mm shorter crank on the left side (I use Shimano cranks and watched ebay to get a good deal). The shorter crank felt weird when I first tried it 10-12 years ago but did not feel weird when I went back to it a couple of years ago. For another bike with equal length cranks, I use shoes with soles for both SPD and Look cleats, and put a Shimano or SIDI three-hole to SPD adapter on the left foot, which gains about 5 mm on that side and allows SPD cleats and pedals on both sides. I do not position the cleat farther forward on the left shoe, but when riding my mountain bike with platform pedals, the left foot is naturally positioned farther back on the left pedal. (I'm still searching ebay for a reasonably priced 165 mm SRAM Dub left crank.) Good luck. I hope some of these ideas will work for you.
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Old 12-05-2020, 09:35 PM
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Cornfed Cornfed is offline
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DON'T Do This

Not a method I'd recommend, but (somewhat) interesting story: When I had to have my left hip replaced in my 40's due to an old Bo Jackson-type injury the ortho discovered my left leg was over half and inch longer than my right (explaining a lifetime of back problems, etc.), so when they put the new hip in they evened me out. Back problems got a lot better and my golf game improved overnight. Like I said, I wouldn't do it if I didn't have to, but kind of an interesting "side effect".
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Old 12-05-2020, 10:53 PM
robt57 robt57 is offline
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My wife also got length corrected when she had a hip replacement. 1" and it caused back issues that are all but gone.

I don't know if getting some the correction with a shorter/longer crank arm is viable... Just a thought.

I seem to recall that adjusting for 1/2 the discrepancy is typical, rather than all of it...
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  #6  
Old 12-06-2020, 07:25 AM
Peter P. Peter P. is offline
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A podiatrist or cobbler should be able to provide you with shim material. Consider using multiple thin shims rather than one shim to make up the difference you're trying to achieve.

As for longer screws, McMaster-Carr has everything. You may have to grind down screws that are slightly too long. Use the appropriate nut to re-tap the screws. In some cases you can get away with just adding an extra washer or two.

Consult Dr. Andy Pruitt's book, Complete Medical Guide for Cyclists, for how-to.
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Old 12-06-2020, 08:26 AM
djg21 djg21 is offline
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Quote:
Originally Posted by NeauDL View Post
You'll probably need multiple approaches to compensate for such a large leg length discrepancy. I try to compensate about 8 mm because of a shorter left leg. I use an extra 3 mm thick insole in the left shoe. I also have a 5 mm shorter crank on the left side (I use Shimano cranks and watched ebay to get a good deal). The shorter crank felt weird when I first tried it 10-12 years ago but did not feel weird when I went back to it a couple of years ago. For another bike with equal length cranks, I use shoes with soles for both SPD and Look cleats, and put a Shimano or SIDI three-hole to SPD adapter on the left foot, which gains about 5 mm on that side and allows SPD cleats and pedals on both sides. I do not position the cleat farther forward on the left shoe, but when riding my mountain bike with platform pedals, the left foot is naturally positioned farther back on the left pedal. (I'm still searching ebay for a reasonably priced 165 mm SRAM Dub left crank.) Good luck. I hope some of these ideas will work for you.
You should have custom shoes made as a start. https://lamsoncycling.com/. You should talk to Don Lamson about options.
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Old 12-06-2020, 06:26 PM
HiddenShadow20 HiddenShadow20 is offline
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Djg21, I looked at the Lamson cycling shoes but they are simply out of my budget. $1300 for a pair of shoes is simply too much for me but I appreciate the info
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  #9  
Old 12-06-2020, 06:50 PM
djg21 djg21 is offline
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Originally Posted by HiddenShadow20 View Post
Djg21, I looked at the Lamson cycling shoes but they are simply out of my budget. $1300 for a pair of shoes is simply too much for me but I appreciate the info
If you have a medical issue, you might look to see what your insurance or any Flex Spending would pay for.

You also might want to look into Tom Slocum at https://www.hscycle.com/index.html.

A discrepancy of 1” isn’t going to be properly addressed with shims. Slocum apparently works with varying crank lengths and oval chainrings to address large differences in leg length.
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Old 12-07-2020, 09:52 AM
soulspinner soulspinner is online now
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Had 22mm of leg length difference for decades(football injury). Used custom built shims(aluminum under cleat) for 9mm of it and a 2 mm inside shoe insert. The word then was make up half the distance. Since had my 3rd hip surgery and legs are exactly the same now in length . It was nice to get new shoes and throw away the shims but I had a lot of good seasons with the half difference route.
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  #11  
Old 01-13-2021, 12:54 PM
Old School Old School is offline
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Quote:
Originally Posted by djg21 View Post
If you have a medical issue, you might look to see what your insurance or any Flex Spending would pay for.

You also might want to look into Tom Slocum at https://www.hscycle.com/index.html.

A discrepancy of 1” isn’t going to be properly addressed with shims. Slocum apparently works with varying crank lengths and oval chainrings to address large differences in leg length.
^what this guy said

A different crank arm is the fastest, cheapest, and likely also the best solution.
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