standard pedal threading

[shankldu]

The Military has left me with my right leg 3/4 inch short , so i must drill and tap a new pedal hole higher up my crank arm . What is the standard threading 9/16 rt hand for most right crankarms?

[dzxc]

Uhh, you know you can get spacers to go between your cleat and shoe for exactly this purpose. And even easier, lifts that go inside the shoe under the insole.

[dustyrider]

Would a different length crank arm work?

[regularguy412]

Originally Posted by dzxc

Uhh, you know you can get spacers to go between your cleat and shoe for exactly this purpose. And even easier, lifts that go inside the shoe under the insole.

Shims are good. 3/4 inch is quite a tall set, tho. I've also used inserts that go IN the shoe under the insole, but you have to be sure to get a shoe a bit larger or you run out of volume inside the shoe for the inserts, insole, sock and foot. So if you get a shoe large enough to accomodate all of the above, the other foot will feel quite small inside the other shoe.

I have a leg length discrepancy due to a compression fracture of L3 which makes my right leg about 8 mm short. I shim for about 4 mm (or about half the difference). You might try shimming the cleat on that side by about 3/8 inch with no or just one insert inside the shoe under the insole,,, and then see how ya go.

Mike in AR

[dzxc]

Yeah, and changing up one crank arm would get you the rest of the way there. I can't imagine re-drilling a second pedal hole is safe.

[pinkshogun]

9/16" x 20 is the pedal thread

[spartanKid]

Originally Posted by dzxc

Yeah, and changing up one crank arm would get you the rest of the way there. I can't imagine re-drilling a second pedal hole is safe.

I would definitely be worried about this too, especially with hollow arms or arms that have some material machined out of the back side for lightweighting.

Especially if you're running a square taper crankset there are tons of options for mixing and matching crank arms to get the right lengths

[regularguy412]

Additional thot: Worse comes to worst, you could get crank shorteners like are used on a kid-back for a tandem. I still have a set from when my kiddo used to ride with me. Just use one on one side.

Mike in AR

[Louis]

You could contact daVinci:

http://www.davincitandems.com/components/

[shankldu]

I have tryed every thing listed . The shims suck ,and move around ,and have poor interface w cleat . A block of lamenent floor works far better ,but when off the bike makes walking weird . I dont have two diferent size shoes to acomodate the lift . I have a shorter bmx 160 mm crank arm on right side , even thought the square taper setup is heavy i guess iits the best i can do .

Originally Posted by shankldu

The Military has left me with my right leg 3/4 inch short , so i must drill and tap a new pedal hole higher up my crank arm . What is the standard threading 9/16 rt hand for most right crankarms?

[ultraman6970]

3/4 inch is around 19 mm... the solution is a combination of things... like 5mm in shims, move the cleat forward, set the saddle height like in the middle between the long and short leg, one leg will run low and the other one tad in the high side, then to finish swap one crank for a 165 mm that pretty much is the shortest one you can get in shimano and campagnolo now a days. The idea is not make the thing look dork (in the good way of the word).

ps: all depends on the lenght of the cranks the op uses anyways.

[Tandem Rider]

I seem to remember that back in the '80s the conventional wisdom from the National Team was 50% of the difference was the compensation. so 3/4" would be a 3/8" shim. The theory was that you already were accustomed to compensating somewhat simply by living with it while running, walking, etc. and 100% compensation seemed to bring about issues of it's own.

They put a 50% shim under my cleat and the knee problem completely disappeared. I still use a shim.

[achurch]

Might be worth the investment. I forget who sells it, but people here will know. I even thought there was one in the classified a while back, could do a search for it. That would allow you to experiment freely.

[Ti Designs]

https://docs.google.com/document/d/1...it?usp=sharing

https://docs.google.com/document/d/1...it?usp=sharing

I've done both custom cranks and custom shims, but the really tricky part is getting the fit right. A shorter crank is also going to move the pedal back as you're pushing down on it, so there will be a shift in the SI joint. Getting it right is almost always a combination of cleat placement and crank length. I'm not interested in trading leg length issues for back problems...

[FlashUNC]

Drilling out a crank is a really, really bad idea.