Hi
Any thoughts would be greatly appreciated on how i can try to solve a knee pain problem? I have had a bike fit by an experienced fitter. I am in a resonably good aero position (i guess) and i can produce good power in this position.
Details:
-first off - no pain with my road bike fit which has my saddle much further back
-knee pain is on the inside of my right knee while on TT bike
-My position has me slammed very far forward (on a p5). i am in a good aero position and with my hips open (or at least much more so than in my road position)
-Every once in a while my right knee does brush against my top tube.
-i ride with 175mm cranks (way too long for slowtwitchers i know but i have been racing bikes since 1988 and this is what i always used)
-6 feet tall, 56cm bike
What would help or is it a matter of experimenting?
-more stretching on hamstrings?
-more stretching of quads?
-shorter cranks?
-moving seat back to a more “road” position? - this is my guess as to a solution but i would then be sacrificing my aero position and my run off the bike.
Thanks slowtwitchers!
Too many unknowns to guess, but I’d take a careful look at minimum knee angle at the top of the pedal stroke. That’s where your 175mm cranks would be likely to cause the most trouble that could lead to knee pain. Of course cleat positioning and or shimming/wedging could be part of the issue but hard to see why that would only be a TT bike issue if you’re using the same shoes and pedals on both bikes.
I’d also look at knee angle at full extension and how that compares between your road and TT bikes. Pain towards the front of the knee is often associated with a low saddle so how do the effective saddle heights (in your actual riding positions under load) compare between the two bikes?
Have a look at some of these images of max and min knee angles: http://bikedynamics.co.uk/guidelines.htm
Did your fit start ground up with the pedals and cleats and look at things like cleat wedging? Lateral knee pain is often associated with knee tracking issues which could be cleat placement including Q factor, cleat wedging or both.
If your fitter does the whole package including cleat fitting and wedging then I’d go back and discuss the knee pain. If not I’d look for a fitter that includes cleat shimming and wedging.
Good luck,
-Dave
The best clue there is your right knee brushing your top tube. Sounds like a knee tracking issue which could be remedied with a wedge or three.
Also, seat height between the bikes might need to be different. Riding forward on the seat of a TT bike and normally on the seat of a road bike will necessitate a slightly higher measured seat on the TT bike to have the same effective seat height.
There’s a chart in this thread that provides some general fixes based on what is hurting. It might help.
http://forum.slowtwitch.com/gforum.cgi?post=4544474;search_string=knee%20pain;#4544474
THX! i will look at the angles tonight. I already shim my shoes to solve a knee tracking problem from my road bike. I use the same shoes on my TT bike (same pedals also) - Is is possible that i might need more shims due to increased angles on the TT bike? Perhaps i need to set up different shoes?
I will borrow some 165mm cranks to see if that helps also. Nee to do some experimenting it seems. (hard to do however as knee pain does not come on suddenly but over time…)
My saddle height is slightly higher than my road height right now.
Stretching and strengthening your hamstrings and hip flexors wouldn’t hurt. Most triathletes have weak hamstrings when compared to their quads.
THX! i will look at the angles tonight. I already shim my shoes to solve a knee tracking problem from my road bike. I use the same shoes on my TT bike (same pedals also) - Is is possible that i might need more shims due to increased angles on the TT bike? Perhaps i need to set up different shoes?
I will borrow some 165mm cranks to see if that helps also. Nee to do some experimenting it seems. (hard to do however as knee pain does not come on suddenly but over time…)
My saddle height is slightly higher than my road height right now.
Sounds good, just know that dropping down to 165mm cranks from your current 175mm cranks can result in a lot of changes. If your current seat height is good (may or may not be given your knee pain) you’d want to raise your saddle a cm and possibly move it back a bit. But that increases your seat to pad drop which may or may not be good but it does also open up your minimum knee and hip angles at the top of the pedal stroke which is often a good thing. So the short crank experiment might be good but unless you’re pretty sure your current saddle is low it can mean several other changes to keep everything where you want it.
-Dave