Author Topic: Knee pain from cycling  (Read 646 times)

bushwacka

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Re: Knee pain from cycling
« Reply #15 on: June 23, 2011, 06:50:41 pm »
i have extremely strong legs, but even last year when I played around with 180cm VS 175 and 172.5 cranks on my road bike with an SRM the 180s had one downside. My 5 second power(IE sprinting)  dropped by 223 watts from 175 to 180, IE the 180 was less power, My 1 minute, 5 minutes and functional threshold all went up with the 180s. the 172.5 were not better in any time range in fact they for me the jump from 180 to 175 was less than 175 to 172.5.

I have no idea how to make a graph for this from my SRM files but here is what I have all number in watts, realize that outside of the 5 second time these numbers are nothing special for a 175lb cyclist.

180
5 second  - 1621
1 minute - 767
5 minute - 409
FT - 313

175
5 seconds  - 1844
1 minutes - 721
5 minutes - 393
FT - 298

172.5
5 seconds - 1656
1 minutes - 656
5 minutes - 310(biggest drop off)
FT - 274

the deal is no matter what I did on any of my bikes my knees just simply would not agree with 180s. Not to mention the clearance problems when MTBing, Cross riding or Crit racing. In crit racing your 5 second power and sprint is the most important thing.  I really need to get a pair of 177.5 to try out and see if I can make them work. BYW Sven your cranks are 177.5 they dont make 178 and I bet it says it on your cranks somewhere what size they are.  I also want to add that my average cadence when road riding is 97 rpms depending on the day. I can grind with the best of them but can spin with the best of the as well. Its what riding a SS bike will do for your pedaling.

I do find it funny that hard core roadies insist on running 172.5 so that can spin faster and smoother, which doesnt mean more power.