My left femur was broken in a car/bike accident many years ago, and resulted
in my left leg being about 1" shorter. I have always dealt with this on the
bike by putting some shims under my left cleat (about 3/8") which I thought
helped. However I notice that I don't get as much power out of my left leg
as my right.
I called and spoke with Tom at HS Cycle this morning. He is extremely
knowledgeable on how to properly deal with this issue, and exactly what
their business is all about. He is 20+ year veteran Cat 1 racer, and has
been doing this stuff for a long time. What I gleaned from about 30 min on
the phone with him is that diagnosing and dealing with leg length issues is
not a simple or inexpensive situation.
Shortening crank arms, lengthening arms with extensions, shims, wedges etc.
does not automatically solve problems and can create additional adverse
issues. I wanted to get some simple shoe wedges, and this will change
pedaling dynamics to benefit the bottom of the stroke and actually adversely
affect the top of the stroke. To do it right, you have to have video work
done of you on a trainer, they loan you an adjustable crank system (below),
and eventually manufacture and sell you a custom crank set with pedals.
This will run about $1700. Since like most racers, I own more than one
bike, you need to do the math and multiples. I am having to think on this
one some more.
http://www.hscycle.com/Pages/adjustablecranksystem.html
-----Original Message-----
From: obra-bounces@list.obra.org [mailto:obra-bounces@list.obra.org] On
Behalf Of Don Whitehead
Sent: Thursday, June 07, 2007 6:58 AM
To: obra@list.obra.org
Subject: Re: [OBRA Chat] crank adaptor for unequal length legs
A couple of other options for crank arm shortening:
http://bikesmithdesign.com/index.htm
http://www.bikemannetwork.com/biking/p/COMPCRNKTDM/CR8873
On 6/7/07, Philip D. Barila wrote:
>
>
> Is this: http://www.hscycle.com/Pages/cantsandwedges.html
> what you had in mind? I can't tell if it rotates or not. If it doesn't,
it
> seems like it's no different than using different length arms.
>
> Seems like if you are going to use different arms, you would want to put
the
> short arm on the short leg side, since the typical way to size cranks is
by
> leg length.
>
> I don't know if that's what you are looking for. That site also has a lot
> of other crank options. Hope some of it's useful.
>
> Phil
>
> Philip D. Barila (303) 776-1264
> Jesus is the main thing!
> PBarila@Barila.Net
> MSN Messenger: PBarila@Barila.Net
> AIM: Phil Barila
> Do you sponsor a Child of Compassion yet?
> http://www.compassion.com
>
> ________________________________
> From: obra-bounces@list.obra.org [mailto:obra-bounces@list.obra.org] On
> Behalf Of Michael O'Hair
> Sent: Wednesday, June 06, 2007 10:16 PM
> To: obra@list.obra.org
> Subject: Re: [OBRA Chat] crank adaptor for unequal length legs
>
>
>
>
> This the usual second approach. The first is to use a longer crank on the
> short leg side. This approach puts the "long leg" foot lower on the
bottom
> of the stroke and higher at the top of the stroke. Instant imbalance.
>
> To make the problem a bit more clear, my left leg is an inch and a quarter
> shorter ( in the ankle ) than the right, so a couple of millimeters is not
> going to make much difference.
>
> I raced for years with a lift on the bottom of my left shoe. I'm not the
> only one. There have been several people with similar problems.
>
> I will do an "ASCII-graph" depiction and your mailer will do god knows
what
> with it:
>
> > | |--++
>
> > | | ||
>
> > | | ||
>
> > | | ||
> > | | ||
>
> > | | ++--(0)
>
> > | |
>
> > | |
>
>
> > | |
>
> > | |
> > | |
> > ++[ ] Bottom Bracket
>
> Where ++ represents a pivot bearing and --(0) represents the pedal.
>
> Note that the diagram shows the adaptor at the top of the stroke.
>
> Please let's not get into a cycle of techno-onanism. If you know if these
> are still made and by who, let me know.
>
> Thanks.
>
>
>
>
> ----- Original Message -----
> From: Mike Woods
> To: Michael O'Hair
> Sent: Wednesday, June 06, 2007 8:41 PM
> Subject: Re: [OBRA Chat] crank adaptor for unequal length legs
>
>
> Just use two different sized crank arms 170 on short leg 172.5 or 175 on
> long leg ?
>
> ----- Original Message -----
> From: Michael O'Hair
> To: obra@list.obra.org
> Sent: Wednesday, June 06, 2007 7:31 PM
> Subject: [OBRA Chat] crank adaptor for unequal length legs
>
>
>
>
> Some time ago, I saw a device made by someone in Colorado that dealt with
> the unequal leg length problem by effectively lowering the longer leg's
> crank arm. Hard to describe but it screwed into the standard pedal
threaded
> hole and then accepted the pedal on the other end of the device. (
> Supposedly, Alexi Grawal used one to deal with his 1 1/4" length
difference.
> )
>
> The attraction is that I could wear mountain bike shoes and be able to
walk
> when I got off the bike and be able to have a reasonably circular pedaling
> stroke when I'm on the bike.
>
> If this rings a bell, let me know.
>
> Thanks.
>
>
> ________________________________
>
>
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