veloce crank stiffness ?

Discuss light weight issues concerning road bikes & parts.
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kom
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by kom

when standing on the pedals the chainrings flex and tuch the FD.
when i looked very good at the problem, i notice that its the bb area that is flexing (mybe the frame) or the bb connection to the crank.

is a chorus bb can fix the problem ?
or its better to go fro full combo like ultegra 10,and if so, Is ultegra 10 will work with my campy 9 groupe ?

by Weenie


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nexusheli
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by nexusheli

Veloce crank won't work on standard chorus or record BB. Chorus and Record BB use shorter spindles and don't allow enough clearance for the Veloce crank. You would need to use Chorus triple BB (111mm spindle) to work, even then it may not be long enough.

campymatt
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by campymatt

This is the same problem I had with the Record cranks. The Campy bottom bracket and crank interface is not the stiffest design available- hense why everyone changed to the octalink, isis drive etc. The best option if you want stiffness at the bottom bracket is to go for the three-piece style crank, either FSA or Shimano.

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divve
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by divve

The Record BB is practically as stiff as the DA9 Octalink. Now, that's suddenly not enough :?:

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Adrien
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by Adrien

In my opinion, your frame should be too much flexy. The crankset are usually very stiff, anyway really stiff enough for non pro riders!

fdegrove
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by fdegrove

Hi,

Now, that's suddenly not enough


LOL....

In case you haven't noticed yet, it can never be stiff enough nor light enough. :?

The Chorus and Record BBs are more than stiff enough for any normal athlete, i.e. if you don't resemble an overblown bull you'd be just fine.....
There's no point whatsoever to go overboard on BBs when the surrounding elements can flex. Think holistic.

Another possible advantage of the Campa's 102mm BBs is a better Q-factor if they're used with the better cranks.
That, to me at least, would be a far more important factor than just absolute stiffness alone.....

Ciao, :wink:
Last edited by fdegrove on Fri Jun 10, 2005 12:36 pm, edited 1 time in total.
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asphaltdude
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by asphaltdude

divve wrote:The Record BB is practically as stiff as the DA9 Octalink. Now, that's suddenly not enough :?:


Indeed. For decades the square tapered interface has been stiff enough, but nowadays it isn't anymore :lol:
Whow! That's a pretty damn nice garage door!

doozer
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by doozer

track sprinters ride the campag pista or shimano dura-ace cranksets which seem to be same as the older alu road cranks but with only 1 chainring. These guys put out about 1500-2000W at times. i haven't seen a mass changeover to octalink /external bearings / oversized cranks on the track yet...

Doozer
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kom
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by kom

so, if the veloce bb stiffnes is enough (as u say)
the problem is from the FRAME's BB AREA ????

brianwchan
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by brianwchan

Yes, if you're riding an older steel frame that may be the case.

I have veloce cranks on an old steel bianchi, and it flexes when i sprint on it.

I have chorus on a stiff alu frame, i get no deflection whatsoever. There's nothing wrong with square taper IMO.

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kom
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by kom

its an Pinarello surprise !! ALU frame - Deda 7005 T6

fdegrove
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by fdegrove

Hi,

I have veloce cranks on an old steel bianchi, and it flexes when i sprint on it.


Incidentally I have an old steel Bianchi Rekord 748 with a Shimano RX100 group.
It always flexes somewhat, scraping the FD cage when I climbed.
I temporarily had the same group transferred to a much newer aluminium Bianchi EV2 with addmitteldly a shorter spindle (107mm as opposed to 113mm Shimano BB Campa style square taper) BB and there's no flexing whatsoever.
So I assume at least some of the flex must be due to the BB shell construction and frame build.

Ciao, :wink:
Being a snob is an expensive hobby.

by Weenie


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