I’m setting up a new bike for '08 and am considering running 172.5 cranks instead of 175. I’m 6’0" tall and have always used 175s, but was thinking that the shorter cranks might allow me to increase my cadence a bit more. it’s something i’ve been working on over the past few years as I’m a bit of a grinder, so it’s getting better - but will the crank length make any difference to me?
I tried it and it definately is noticable. You can spin more and don’t close your hip angle as much.
did you do the same drop as i did 175 ot 172.5? then did you raise your seat up 2.5mm so that your pedal to saddle was still the same?
I ride 175s on my road bikes (raced USCF that way for years), and went with 172.5s on my tri bike. Noticeable with the hip angle. YMMV.
I did …175 down to 172.5…to me it feels much better…
No. Waste of money to switch down 2.5 mm. I don’t care what anybody says, it won’t make a difference, other than a placebo effect. Besides, you should use longer cranks on a TT bike. You can use .21 to .216 x your inseam (in mm) to determine ideal crank length (according to Zinn http://www.zinncycles.com/cranks.aspx).
I just attended a John Cobb lecture in St. Louis MO this week, and this exact question came up. John said a longer crank arm will make your muscles feel better. They (your muscles) have more room to move. Muscles like to elongate. They don’t like to be bunched up. If your muscles feel better you feel better. Then the possibility of you riding harder/faster/or whatever increases.
Longer cranks won’t improve your power or strength. Not sure if he mentioned anything about cadence.
Bottom line, if you try it and you like it…it works.
That is what I got out of that portion of the lecture.
I asked this a while back and just recently on BT. From what I got… 2.5mm will make no difference. If you dramatically change it crank length then you will feel a difference but from 172.5 to 175, and even 170- chances are you will feel nothing different.
The money isn’t the issue since i have a pair of both already (a frame i bought came with 172.5). I realize that conventional wisdom says longer cranks on a TT bike, but I thought that was so that you could ger more leverage out of each pedal stroke and produce MORE power in a TT (where you are trying to maximize power and speed). Since i’m riding at way below my threshold I’m not looking for extra power - i’m looking to increase my cadence.