Bicycle Mechanics - Check this out: ranking crank stiffness

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531Aussie
04-18-05, 11:33 PM
http://dura-ace.shimano.com/publish/content/duraace/en/home/the_product0/drive_train.ExtraMainContentPar.0017.File.tmp/VN-crank-results-web.pdf

anyone have anything similar?

cs1
04-20-05, 09:08 AM
Published by ShimaNo I take it.

Tim
531Aussie
04-20-05, 09:10 AM
well, it IS on a Shimano site:)

ewitz
04-20-05, 09:18 AM
a little older but still interesting:

http://www.bikesportmichigan.com/reviews/crank.shtml
531Aussie
04-20-05, 09:19 AM
cooool, thanks
KleinRider
04-20-05, 11:27 AM
I like how the shimano data is incorrect in their table. The bottom two cranks (which presumably are the least stiff based on their text) have higher values than all but the Dura-ace crank. I guess they left a zero out, right before the 5.
camaddy
04-20-05, 12:53 PM
Published by ShimaNo I take it.

Tim

Actually it looks like a legit test published in VeloNews. And if it were a paid advertisement by Shimano, why would they recommend TruVativ in the last paragraph as the best all-around value? You guys must really hate Shimano.
H23
04-20-05, 01:14 PM
Typical baloney engineering in the bicycle world.

I really don't see the validity of that test. How much does elastic deflection of the crank really matter, anyways?
AndrewP
04-20-05, 03:05 PM
I think deflection of the crank is probably less than the deflection of the frame.
khuon
04-20-05, 03:19 PM
This test doesn't really measure the crank itself as much as the entire system including the chainrings. I'm wondering if they used the same chainrings for all the tests... probably not. Additionally, I think the importance of this test is probably overrated. I'm reminded about all those statistics involving SUVs and horsepower. The newer SUVs have a lot of horsepower but at RPMs way above their useful range... especially for offroading. What most people fail to look at is the torque curve. I think this crankarm stiffness thing is much along those same lines.
Zouf
04-20-05, 05:13 PM
I like how the shimano data is incorrect in their table. The bottom two cranks (which presumably are the least stiff based on their text) have higher values than all but the Dura-ace crank. I guess they left a zero out, right before the 5.
You seem to be referring to the last column; there is no error there, that is a measure of stiffness per weight per dollar, one very weird measure if there ever was one. It's based on this that the article concludes the Truvativ is good value. I guess this means if your crank is half the price, it can be half as stiff and still be as good as long as it weights the same as another one. Duh...

And it is a Velonews article, not Shimano data. Well, not directly Shimano data anyway.
KleinRider
04-21-05, 07:48 AM
You seem to be referring to the last column; there is no error there, that is a measure of stiffness per weight per dollar, one very weird measure if there ever was one. It's based on this that the article concludes the Truvativ is good value. I guess this means if your crank is half the price, it can be half as stiff and still be as good as long as it weights the same as another one. Duh...

And it is a Velonews article, not Shimano data. Well, not directly Shimano data anyway.

ah, yes. My mistake. :o Thanks for pointing that out.