Will SRAM 1x cyclocross RD work with 2 chainrings?

Nick Payne

I need a rear derailleur to use with some SRAM Force 22 shifters and a wide range SRAM 11-36 cassette. A friend has offered to send me a free Rival 1 cyclocross RD - the alternative being to purchase an X9 or equivalent 10s MTB RD. The Rival 1 is only intended for a 1x system, and has the top pulley further away from the pivot point of the derailleur cage than a conventional derailleur intended for use with multiple chainrings, so the vertical position of the top pulley will change more when changing between the chainrings. Has anyone actually tried using it with two chainrings? I tend to think that it won't work, due to the pulley position, but if anyone can say otherwise, I'll be more than happy to avoid the cost of purchasing a rear derailleur.

The Rookie

Almost certainly not, the issue is that being designed for a 1x with similar cassette capacity (max teeth- min teeth) it almost certainly won't have enough capacity to cover the extra required by the front chainring shift as well. Nothing to do with the Pulley position which while sub optimal will probably not be an issue, in fact the tech doc says it will be fine (see below)
Get an X9/X0 would be my suggestion.
https://www.sram.com/sites/all/themes/s ... ide_EN.pdf
Max capacity stated is for an 11-40, so 29t, your 11-36 needs a capacity of 25T, so as long as your chainrings are within 4t (OK maybe you'll get away with 6-7T) of each other it would work, otherwise (with a long enough chain for big/big) it will be as slack as a 'lady of the night' knicker elastic in small/small.