Chainrings for Campy Chorus/Record CT Cranks

D'ohBoy said:

Hi -

Torn about whether to go with 34/50 or 36/50. Are the rings a matched
set (pickup pins, machining etc....) or could I purchase an additional
small ring of the other size and use it without affecting shifting
performance?

TIA

D'ohBoy

1. I'd go with the 48/34 chainring option Campagnolo offers. In
numerous gear charts I've done with Campagnolo cassettes, the 50 tooth
ring just does not work. The 48 produces the proper gearing steps.

2. I have normal Campagnolo matched rings on my bike, 53/42. The 53
says its designed to work best with the 42 ring only. On very rare
occasions I've replaced the 42 with a 39, creating a mismatched pair.
I never noticed any change in front shifting. I doubt it makes any
difference if your rings are matched or not.

3. Why would swapping the 34 and 36 rings make any real difference in
gearing on the bike? What situations would the 36 ever be better than
the 34 to cause you to make a change? If you want to switch inner
rings, get a TA 38, 40, or 42 tooth inner ring to go with your 50.

Russell responded to my inquiry:

Quoted message said:

I'd go with the 48/34 chainring option Campagnolo offers. In
numerous gear charts I've done with Campagnolo cassettes, the 50 tooth
ring just does not work. The 48 produces the proper gearing steps.

I am somewhat insensitive to gearing steps - just as happy with my
13-29 and 12-25 (as long as I can get up all the hills on a ride). I
am much more interested in range.

And asked:

Quoted message said:

Why would swapping the 34 and 36 rings make any real difference in
gearing on the bike? What situations would the 36 ever be better than
the 34 to cause you to make a change?

Markleeville Death Ride = 34t, Riding the Driftless Zone in WI = 36.
Bumps the gear ratios about 2t up or down. And most likely cheaper
than a custom 32 tooth 10s campy cassette. Although I have been
considering it (anysystem.de or other).

And further commented:

Quoted message said:

If you want to switch inner
rings, get a TA 38, 40, or 42 tooth inner ring to go with your 50.

Campy has proprietary bcd (one bolt is off the 110 bcd).

Thanks for your input.

D'ohBoy

-snip-

Quoted message said:

Russell responded to my inquiry:

Quoted message said:

If you want to switch inner
rings, get a TA 38, 40, or 42 tooth inner ring to go with your 50.

D'ohBoy said:

Campy has proprietary bcd (one bolt is off the 110 bcd).
Thanks for your input.

Only in carbon.
The new 2006 aluminum compacts are 110 all over.
And we make 110-112 rings here for the carbon cranks, as do
others.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

D'ohBoy said:

Hi -

Torn about whether to go with 34/50 or 36/50. Are the rings a matched
set (pickup pins, machining etc....) or could I purchase an additional
small ring of the other size and use it without affecting shifting
performance?

TIA

D'ohBoy

I looked at my Record 48/34 compact crankset closely this evening. All
teeth of the little ring have the same shape and I can not discover any
relative position to the big ring. The pins on the big ring have a
relative positon to the machined theeth of the big ring. So I would
expect that swapping a 34 for a 36 T ring would be no problem. Why the
big ring on my crankset has 48/34 stamped on it is a mystery to me.

Lou
--
Posted by news://news.nb.nu

Lou Holtman said:

D'ohBoy said:

Hi -

Torn about whether to go with 34/50 or 36/50. Are the rings a matched
set (pickup pins, machining etc....) or could I purchase an additional
small ring of the other size and use it without affecting shifting
performance?

TIA

D'ohBoy

I looked at my Record 48/34 compact crankset closely this evening. All
teeth of the little ring have the same shape and I can not discover any
relative position to the big ring. The pins on the big ring have a
relative positon to the machined theeth of the big ring. So I would
expect that swapping a 34 for a 36 T ring would be no problem. Why the
big ring on my crankset has 48/34 stamped on it is a mystery to me.

Lou
--
Posted by news://news.nb.nu

They like to match pickup pin/ramp placement of the big to the small
but in actual use it means nada...