Knee pain

godders1

Did my first commute today on my new Pompetamine (17 miles e/w Bath-Bristol). A pretty nasty pain developed in my left knee which pretty much ruined things, especially on the way back (took me over 2 hours!) It feels like it's almost on the surface of the knee on the bottom part of the knee cap and pretty much as soon as I get off the bike the pain goes away.

I've had similar issues before on my old bike and I sorted them by raising the saddle so tried this but it didn't work.

I intend to go to the docs and try and get a physio referral but just wandered if anyone's had anything similar?

I noticed the cranks are 165mm (these are the only Alfine cranks On One had in stock). Seems pretty short so wander if this could be a potential cause (I'm 6' with a 34" inside leg)?

Team4Luke

can only guess, although cranks sound too small for you, and you should stay with what length you had before, but it is the distance from bottom of the pedal stroke to top of saddle that is important and may have changed sufficent to "upset" your knee. Measure your other bikes and recheck.

godders1

Team4Luke wrote:

Measure your other bikes....

Why the hell didn't I think of that? :oops:

cheers

The Rookie

As a rule of thumb, sitting on the saddle your leg should be just a fraction off straight with your heel on the pedal.

Simon

phy2sll2

Is crank arm length a constant between all bikes for any given rider?

I seem to remember hearing that, traditionally, riders would have shorter cranks on their track bikes than road bikes, or is that nonsense?!

Alinshearah

I used to be a cyclist like you, but then I took an arrow to the knee

phy2sll2

Alinshearah wrote:

I used to be a cyclist like you, but then I took an arrow to the knee

godders1

From what I've been reading, anterior knee pain can be caused by crank arms that are too long so I'm guessing the crank is probably not the cause in my case.

spasypaddy

phy2sll2 wrote:

Is crank arm length a constant between all bikes for any given rider?

I seem to remember hearing that, traditionally, riders would have shorter cranks on their track bikes than road bikes, or is that nonsense?!

all my bikes have the same length cranks. in fact as a result i have a spare 170mm crankset sitting around at home having done next to no mileage because my other 3 bikes were 172.5

greg66_tri_v2.0

phy2sll2 wrote:

Is crank arm length a constant between all bikes for any given rider?

I seem to remember hearing that, traditionally, riders would have shorter cranks on their track bikes than road bikes, or is that nonsense?!

That is (more or less) right.