I've managed to muddle through for years, but over the last year or so I'm getting pain in the back of my knee (I think it's over extending). It's really hard to decide which leg to set the saddle height for! 3/4" difference.
I think it may need a multi angled approach. Possibly mixed 165 and 170mm cranks, combined with a small cleat wedge. Concerned about hike a bike with deep cleat shims.
Set saddle height for your shortest leg I'd assume. Or like you say mismatched crank length.
My thoughs.
What ever you do, set saddle hight to the shorter leg.
How are you settling saddle hight, position and angle, are you actually able to sit on your saddle correctly?
What sort of riding and pedal systems?
Where is your shorter leg shorter, if its femur then I would be thinking about crank length as it would keep you knee bend more proportionate.
If its below the knee then maybe look at some way of raising the stack hight of your pedal and shoe.
If you don't mind me asking, who determined the LLD and by what method? I've known a few people he told this but it's been pelvic alignment rather than the bones in the leg actually being different lengths. Because of this, so have even had the discrepancy switch from one side to the other.
Fifty quid for a trip to a really good physio would be what I would do
What practical steps have you tried?
A long one and then a slightly shorter one?
Have you seen anyone about it? GP > physio > orthopedics?
I've mucked around with shims over the years but particularly for off road use the practicalities weren't great.
I was certain I had a leg length discrepancy and a saddle pressure map at a bike fitters confirmed that one side of my pelvis sits further back than the other, but shimming the more forward side made no difference, the problem lies in the hip muscles being imbalanced and not firing correctly, which pulls my hips out of alignment.
Do you have any aches and pains other than the back of your knee?
It probably depends where the discrepancy is. If it's in your shin, I'd be stacking the pedal in some way to compensate, if it's in the thigh you want different length cranks
It's a lower leg shortening from having a tibial osteotomy 25 years ago, following on after complications due to a nasty compound fracture.
I've seen SO MANY physios over the years. Recent scan of the knee came back with the expected early arthritis, cartridge issues etc. I just get on with that and keep popping anti inflammatory as an when.
This pain at the back of my knee feels like stretched soft tissues damage, running up and down from the knee. I recently bailed from the Bearbones 300 at the 100km mark. That's the sort of ridding I "enjoy".
Any recommendations for a good bike fitter or sports (understanding of cycling) physio in the Manchester area?
I doubt you will find any better than Phil Burt
https://www.philburtinnovation.co.uk/bike-fit/
Fairlight suggested this one to me https://veloedge.co.uk/
I've not been to either but a friend has been to Phil Burt and reccomends him
@polisherman also if you want a physio try Bartek at http://www.bhphysiotherapy.co.uk/default.html
He's based in Bury.
Say you came via Bill and if he doesn't get back to you, message me. He can be unreliable at communicating!
I saw a physio for issues with my knees and back when I played football. He did some remedial work and then referred me to a sports podiatrist who identified my (presumably genetic) leg length discrepancy. He made me orthotics that worked almost immediately albeit counterintuitively. For the past 19 years I've worn custom made orthotics (obviously not the same ones) and never had the problems again.
However cycling has never caused me any issues.
You are Sandy Irvine and I claim my £5
I’m sure I read somewhere (although it be a figment of my imagination) that Fabian Barel experimented with a shorter crank after he ended up with a shorter leg from braking his femur. I think
Potentially an advantage for track cycling providing you are imbalanced the correct way round