Campagnolo chaingrings

[Shmitt]

I want to ask You about chainrings to 4 arm crankset. every inner chainring (34T, 36T, 39T) like outter chainring (50T, 52T, 53T) has the same bolt circle (112 mm and 145 mm).

Camapagnolo recomends use chainring in pairs 50/34, 52/36, 53/39.
Did any used other combination of chainrings -example 50/36, or 52/39?
If used, can anybody write about how it works in shifting of course.

[graeme_f_k]

I want to ask You about chainrings to 4 arm crankset. every inner chainring (34T, 36T, 39T) like outter chainring (50T, 52T, 53T) has the same bolt circle (112 mm and 145 mm).

Camapagnolo recomends use chainring in pairs 50/34, 52/36, 53/39.
Did any used other combination of chainrings -example 50/36, or 52/39?
If used, can anybody write about how it works in shifting of course.

The shifting is poor by comparison ... the lift pins and ramps are in the wrong places relative to the teeth on the inner ring (they have to be correctly aligned, hence the index marks and in the old 5-arm compact chainsets, the offset bolt) so the outer ring is less inclined to pick up the chain properly. We have done this occasionally with the teams and it's never been a really satisfactory and completely predictable shift.

You will notice that the outer rings designed for use with an even number of teeth on the inner chainring have a different arrangement of pins and ramps to those designed for use with an odd tooth-count inner, as well. This is not an accident - it's to ensure that an outer link plate is always presented correctly to the bottom of a lift ramp (even number of teeth on the ring means that the same teeth always carry an outer link plate - odd number, the teeth always alternate link plates).

[Shmitt]

thank You for the answer.

[BRM]

Graeme is right but . . . . in the era of the 5 arm compact crankset, many people changed the 34 for a third party ring of 39 or 42 teeth. These third party rings didn't had any gearing help. Most riders (enthousiasts) didn't complain really. But when doing races you maybe have different requirements. Also how frequent you change the chain to a different ring is here a factor if it bothers you or not.