These crank length forumlas have got my head spinning
10-14-05, 12:05 PM
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Emondafied
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These crank length forumlas have got my head spinning
I measured my inseam today - 32.75" (831.85mm) and I plugged this into Zinn's crank length formula.
180mm cranks!? I don't think so, I'm 5'10.
So I hit google and find another formula that gives me similar results. Ok, I might try 175's (I'm on 172.5's right now) but anything longer than that seems insane.
I did a search on this forum for "crank length" and found another post by 531aussie that seems to make more sense, and then I found Sheldon Brown's page on crank lengths, so I feel a bit better.
Has anyone tried crazy long (for their height) cranks? I'm wondering what they're like.
180mm cranks!? I don't think so, I'm 5'10.
So I hit google and find another formula that gives me similar results. Ok, I might try 175's (I'm on 172.5's right now) but anything longer than that seems insane.
I did a search on this forum for "crank length" and found another post by 531aussie that seems to make more sense, and then I found Sheldon Brown's page on crank lengths, so I feel a bit better.
Has anyone tried crazy long (for their height) cranks? I'm wondering what they're like.
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Current Stable: Trek Emonda SL - Trek Top Fuel 8 - Scattante XRL - Jamis Dakar Expert - Trek 9700 -
10-14-05, 12:36 PM
#2
Senior Member
Try 175mm, you'll like it.
If you can, do some instrumented testing with time-trials and sprints; longer cranks really helped out my acceleration rate, top-speed is about the same. I'm 5'5" and ride 172.5mm cranks and 165mm on my track bike (primarily for ground-clearance). My MTB has 175mm cranks. I think it comes down to flexibility and smoothness of the spinning motion. A lot of the pro guys have been evolving towards longer cranks as they get faster and faster: Here's a list of pro crank lengths for you tekkies!. What I find more interesting isn't that their current crankarm lengths are, but how it changed over time.
If you can, do some instrumented testing with time-trials and sprints; longer cranks really helped out my acceleration rate, top-speed is about the same. I'm 5'5" and ride 172.5mm cranks and 165mm on my track bike (primarily for ground-clearance). My MTB has 175mm cranks. I think it comes down to flexibility and smoothness of the spinning motion. A lot of the pro guys have been evolving towards longer cranks as they get faster and faster: Here's a list of pro crank lengths for you tekkies!. What I find more interesting isn't that their current crankarm lengths are, but how it changed over time.
