totalnewbie

currently using shimano spd-sl. i have leg length discrepancy - my left is about 2cm shorter. don't know if it's related but I tend to have knee pain on my left after a couple hours on the bike. Not sure if it has anything to do with my discrepancy but I have confirmation bias so of course it does. Have a professional fitter checked. He shimmed up my left shoe using 4 layers and set the cleat on that side a little more forward than the right. also set both cleats inward. All these help relieve but I still have slight knee pain during rides.

I have read somewhere that Speedplay get recommended for people with uneven leg lengths because:

1. they allow for more float
2. you could shim them higher than shimano spd-sl (not sure why this is the case)

For those of you who have LLD and/or knee pain and have used both speedplay and shimano/look, does speedplay help with your issue?

Dunbar

https://www.stevehoggbikefitting.com/...hich-are-best/

JerrySTL

Speedplay X's and Zero's certainly do have a lot of float. The Zero's float is adjustable. However float will only help if you need extra float. Watch your knees and toes/heels while pedaling. Are your knees going straight up and down or making something like a O or even Figure 8 motion? If you knees are moving around, more float might help. How about the toes and heels? If they are staying pointed straight ahead, more float probably won't help. However if you see back and forth movement and it's being stopped by the lack of float, then more float may help.

I ride on X's and could see how they could be shimmed up. The cleat is actually splits apart with three screws holding on the base to the shoe then 4 screws holding the cleat to the base. You could shim up between the base and shoe.

Have you looked into different length crank arms? If you have a 175 on one side and a 165 on the other, that's 10 mm taken care of. I knew of one rider with a leg length difference who did this.

I have a slight leg length difference plus a 1/2 shoe size difference from a club foot birth defect. Fortunately mine is so minor that I don't have to make an adjustments to it.

fstshrk

I had to switch my left side from the red Keo cleat to the grey keo cleat to get rid of some weird knee pain. So if I were going to Speedplay, I would go with the adjustable float Zero.
As far as 2cm leg length discrepancy, you need the cleat shims.

Looigi

Typical things with leg length discrepancy are to shim half the discrepancy, move the cleat back on the long leg and forward on the short leg, and rotate the nose of the saddle a couple of degrees to toward the long leg. One or a various combination of these may be appropriate.

arcticbiker

I ride with the X-1's and have had good luck with them except for walking in them. The X-1 product information says

"Leg-Length Discrepancy?
The Speedplay Leg-Length Shim Kits (part #13220 sold separately) can be used to shim the X Cleat in
1/3 cm (~1/8 inch) increments to correct leg length discrepancies. Call Speedplay for technical
assistance toll free at 1-800-468-6694 (PST)"

Speedplay offers several shims and mounting plates for different shoe manufacturer's. It might be worth a toll free call to discuss your particular concern.

Number400

Get a longer crank arm on your left side

thump55

I can't speak for other brands, but the adjustable float on the SP Zeros is nice because you can adjust it to hold your foot in any position, or allow float as needed. They give you the most flexibility.

raiden07

Longer crank means larger diameter pedal stroke; his shorter leg would need to reach an extra 2cm at the bottom...

Elvo

Not if you replace only one of the arms

raiden07

Crank arms are independent of each other so that's moot.
Bottom bracket distance is fixed. Crank arm length extends above and below the bb.

Think of an extreme where someone's legs was so short that you would suggest a 300mm crank arm length on one side and 170 on the other. The 300mm crank would bring that leg closer to the body at the top of the stroke but at the bottom it would be 30cm below the bb.

totalnewbie

done the first two but can't rotate the saddle since my seat post is not circular.