[Electric_City]

Are they brand specific or can you mix and match? Obviously sticking with the identical disc/mount size (203-203, 180-180). Shimano mount w/Avid calipers, Magura mount w/Hope calipers etc... Or does each mount somehow change the position of the caliper?

 

[Jm_]

You can often mix-and-match, but sometimes the shape of the caliper is not compatible with the adapter and prevents mounting the caliper. I'm running a front formula on my fatbike for my 180mm rotor with my xtr brake and god-knows-what adapters on my RFX.

 

[StiHacka]

The adapters typically move the calipers out by 20mm increments (160->180, 180->200), or 40mm (160->200). As long as you have the correct step up and there's no interference with the caliper body, you can mix and match as desired, as JM said.

Edit - the above applies for post mounts. IS adapters are always matched to the rotor size IIRC but are also interchangeable between brands.

 

[Electric_City]

I was wondering if maybe the mounts were made by each company to fit their brakes profile or something, making it hard to be interchangeable. If most are interchangeable, what was the big deal with the Gustav to 40 mount costing something like $200?

 

[maxyedor]

IIRC the Gustav was 51mm IS and so you had to get a goof IS to post mount adapter that also meant you needed a 10mm larger rotor, then the 40 was a native 200mm mount, so you probably needed something like a 230mm rotor. That could be the reason for a $200 adapter, it was more of an oddball adaptation kit.

Back in the day I remember using a lot of weird ass adapters that cost quite a bit, this is one area where the Industry has actually improved. There's still some weirdness when it comes to 180mm rotors and 4 piston calipers needing different shaped adapters than standards, but otherwise they're all pretty much the same.

 

[StiHacka]

Gustav seems to be an odd animal because Magura?
https://bikemarkt.mtb-news.de/article/1052407-magura-gustav-m-bremssattelhalter-adapter-no-24

 

[Electric_City]

I loved IS mounts. Simple to remove without having to recenter the caliper every time. I just ordered one that I might not have needed to.

 

[maxyedor]

The IS mounts were good for a couple reasons. I always preferred the threads being in the $12 adapter than in the fork lowers, and it's not like we really got away from adapters anyway except in a few specific frame and fork set-ups. They also gave you a little more freedom to shim as required back in the bad-old-days of nothing being machined correctly or built to any kind of reasonable tolerances.

Magura were/are a bunch German dick-holes though and always went direct mount without an adapter so you had to shim your caliper with washers, their brakes were the cat's ass back in the day, but a PITA to keep running rub free. They still have sticky pistons, and still work great, and the company is still run by angry Germans

 

[toodles]

I loved IS mounts. Simple to remove without having to recenter the caliper every time. I just ordered one that I might not have needed to.

Yeah it was great being able to take the brake off without having to line everything up afterwards. Damn lizards

 

[StiHacka]

My 2017 Riot came with an IS mount. It is good.

 

[Sandwich]

I like the IS/post mount adapters for the reasons mentioned above, but things have come a long way since 97 and 22mm post mounts, so things line up pretty well on their own regardless of shims. Unless you own a fox 36, which has some weird 23mm post mount rather than a 20mm, so I have an extra 1.5mm of washers on it. Or maybe I have the wrong adapter. I can't remember.

As for the gustavs, they actually had fully floating calipers that could slide back and forth on those silver pins, just like some cars. The benefit was they were completely impervious to overheating because no matter of warping would bend them out of the way. The downside was wickedly expensive brake adapters and constant brake drag since you couldn't physically center the caliper. I still have a few if anybody wants.

 

[Electric_City]

Well... I ordered the Hope "C" mount yesterday. 3hrs later I remembered that I had about 10 extra mounts in my basement but didn't recall what ones specifically. I opened The Cloud and found a pic. All IS mount except 1 from Avid. The Avid had 203 on it. I got home and compared it to my Spartan.. Mutherf'er!

I just wasted $20. CRC said the order was already dispatched. F'!

 

[HAB]

I like the IS/post mount adapters for the reasons mentioned above, but things have come a long way since 97 and 22mm post mounts, so things line up pretty well on their own regardless of shims. Unless you own a fox 36, which has some weird 23mm post mount rather than a 20mm, so I have an extra 1.5mm of washers on it. Or maybe I have the wrong adapter. I can't remember.

As for the gustavs, they actually had fully floating calipers that could slide back and forth on those silver pins, just like some cars. The benefit was they were completely impervious to overheating because no matter of warping would bend them out of the way. The downside was wickedly expensive brake adapters and constant brake drag since you couldn't physically center the caliper. I still have a few if anybody wants.

The 36 has a direct mount for a 180mm rotor, so I assume you're running a 160-180 adapter (i.e. +20) and a 203mm rotor, which is why it doesn't really work right.

 

[Sandwich]

yep