Force CX1 cage looks odd

You are correct, it is a Rival cage.  I have swapped a Rival cage onto a Force so I am very familiar.  It’s possible this might be an OEM derailleur that used the alloy Rival cage to cut cost. There are actually quite a few OEM components where they do similar things to cut cost but still make you think you are getting high end components.  Also it’s coming from China so it could be a knockoff.  If you are trying to find one at a good price go to Random Bike parts.  They have the long cage for a good price and you can find a 10% off coupon online.  They say it’s a medium, but I ordered two and they are both definitely long cage.


https://www.randombikeparts.com/products/sram-force-type-3-11-speed-cyclocross-cx-road-bike-rear-derailleur-new?_pos=1&_sid=11e5f5cc3&_ss=r