Old 03-26-10 | 10:00 AM
  #4  
FBinNY
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Joined: Apr 2009
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From: New Rochelle, NY

Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter

Originally Posted by joejack951
Chainring spacing has not really changed as the speeds have increased. Chains have gotten thinner and the ramps and pins on chainrings have become suitably more aggressive. That's not to say that no changes at all have been made but they were minor tweaks and AFAIK confined to certain 10 and 11 speed cranksets. Because the ramp/pin changes I would not recommend using a 7 speed chain on a 10 speed crankset. Chainring spacers are likely to create front shifting issues.
I hate to correct folks but this is wrong. 7, 8 & 9s chainring separation is the same, but 10s is definitely less. When Campagnolo made 10s cranks rather than thin the spacer built into the right crank spider, they milled a recess into the outer chainring's mounting area moving it inboard a bit. Don't hold me to this but I believe it was by 0.8mm. This is the only difference between the Campy 10s and 9s cranks and chainrings.

You can ride the 10s cranks with most 9s chains (which will run on 7s cassettes). I'm still using old Sram PC-89r on mine because I didn't want to get involved with Campy's 10s system, and I like the master link. If you don't increase the separation a bit you'll have greater risk of the chain brushing the inner face of the outer ring, while using the inner ring with the outer part of the cassette. In your case I'd set the bike up and try it first, then decide whether to increase the separation or not.
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