On Saturday, March 22, 2003, at 01:41 PM, r cielec wrote:
> I only have experience road riding 144 bolt circle (NR). Is flex a
> problem with 110 and smaller bolt circle for road cranks?
Nope. I actually prefer 110 because of the ring options. I also think
the TA pattern is just fine too and have never had flex issues. Flex
really doesn't get to be much of a problem until you get above 58 tooth
rings. When I was working for Bike Friday this was something we were
always thinking about and tested extensively. Shifting starts to
degrade at about 58 teeth with standard rings. One one of by bikes I
use a 62 tooth Paragon Machine Works ring on a first generation Shimano
600 130mm BCD crank. The small ring is a 50 and I have no problems
what so ever shifting. Maybe Brian B. will chime in here since he
likes BIG RINGS. . . what would Freud say?
> I ride in 52 - 54 rings (benefit of years of cross-country running)
> so, chain ring flex is a concern.
It shouldn't be a concern unless you're using cheap rings or shifting too hard. Rings like the Campagnolo SR rings without the bottom webbing are much less stiff than the overbuilt NR rings. Stepping out on a limb I'm going to say that newer rings are vastly superior to the classic ones. The newer rings are thinner, lighter, and just as stiff as the old one. I think it comes down the the alloys today are better. Some are going to say that they just don't look right on a classic crank. I'd say your question is a performance one not one, not one of classic parts.
On a different note it's interesting that you push big gears. I was a competitive runner for about 10 years (father was a college CC coach) and I'm a spinner. My spin didn't start to come down until I stopped running seriously 12 years ago. I'm a strider when I run and I think my legs find the smooth circles of spinning closer to a natural leg motion than mashing. But hey we're all different machines and what works for one doesn't work for others. good luck, Brandon"monkeyman"Ives SB, CA