Short crank length

[jpb]

Here it goes. I'm 6'3 and usually ride 175 length cranks on my chainset. I have just purchased an ultegra 6700 chainset but with a crank length of 170mm. I know that some people say short is better or vice versa. But...what's the difference. Will 170 be a big difference on hills/flats etc.

Thanks for looking and hope to hear back :-)

 

[gaz]

Longer cranks give you better leverage and effectively make your gear ratio smaller (not a problem on a geared bike). The longer crank also gives your knee more flex.
You normally only notice a difference (pain wise) if you go from shorter to larger, you should be fine.

 

[zexel]

If you wasn't aware of it, you wouldn't notice any difference in 5mm.

 

[albion]

It's 5mm difference at the top and 5m at the bottom. Seat adjusted its an extra 10mm to effect the knee bend.
I'm on 170mm and wonder whether 160mm or 165mm would help my iffy knee. I don't know whether its pressure at the end of each arc or if its overall pressure that is most causal.

 

[jpb]

I do get lower back pain and this was one of the reasons for going shorter because it apparently reduces this. (not a clue how)