Sram Rival flat mount adapters

For a rear brake. Bike came with 160mm rotors and 2 flat mount adapters on the rear caliper. If I size down to a 140mm rotor what adapter would I need? Or do I simply remove one of the existing adapters?

Might help with a photo of the brake setup.

I would but never got photos to work on here. It had the Sram adapter which only goes on one way round and a generic adapterunder it . Both of those worked with a 160mm rotor.

The Sram adapter has odd spacing between the holes; 34mm for the caliper but 70mm which doesn’t fit directly to the frame.

70mm one is the front adaptor.

70mm one is the front adaptor.

Ah ok, it had that on the rear, ontop of a generic 20mm flat mount adapter. Frame is post mount.

Just checked and it says “Rear 160”

It’s also not 70mm spacing. Sorry, got a bit mixed up. It’s one of these:

Link

Ah – didn’t realise the frame is PM…

Pics would help.

Sounds odd.

Spacing on the frame is 45mm. Caliper is 34mm

This gets weirder.

That adaptor you linked to is a FM Rear +20mm adaptor. Two sets of 34mm spaced holes presumably.

FM is 34mm spacing

PM is 74mm.

45mm is ???

What frame?

Think you can only run 140mm rotors with matching flat mount frame and calliper. Any post mount adaptor added in means 160 is the smallest you can run.

Giant revolt.

Holes on the chain stay and 45mm appart.

Guessing it’s this.  Adapter to move the brake when you flip the flip chip to change the wheelbase.

If it’s currently running 160mm rotors, and it’s got a 20mm adapter you should just need to remove the 20mm adapter and bolt the caliper directly to the weird Giant thing.

Yes! That’s it, a flip chip thing for the caliper. Makes sense now. Thanks!