[Sandwich]

I have a 185mm rotor. It's an older HOPE disk. I'd like to run it on my fork, which is IS. I have PM calipers.

Many of the adapters I'm finding say 180mm. Is this a misnomer, or is it accurate? Magura is who I usually use, but they are some wacky dudes. I found an Avid adapter that's 185mm, so I might just go for it. I just want to make sure that whatever I buy is compatible with my stupid rotor.

 

[eaterofdog]

In theory, it should be compatible. But with all the variances in frames, adapters and calipers, you really have to try it and see. I've had stuff that is perfect by-the-book not work at all. And I've had random junkbox builds work perfect. I have a bin of adapters from various bike builds.

If your adapter is a too tall, you won't be able to use it unless you are OK with less that ideal pad/rotor contact. If it's a mm or two too short, you can add some shims (SHIMS SON) to space it up and get perfect match.

 

[project_d]

If it's a 185mm adapter, and you're using a 185mm rotor, you should be fine. I just bought a Shimano 185mm adapter for my Hayes brakes (cuz I went from 203 to 185), and it worked just fine.

 

[samnation]

OK

Shimano and Hope do a "middle" size of 185mm Avid and possibly some smaller manufacturers use a 180mm "middle" size if you find an adapter intended for Avid brakes it will read as 180mm

Ideally in a perfect world you should buy an adapter and rotor made by your brake's manufacturer to work with your brake.

And in case that's not enough Hope also had at one point done a 183mm Rotor so if you are measuring and not reading it off the rotor you may want to check again.