[Closed] Disk Brake Adaptors Urgh!

You need a plus 20 mm adapter. A 160 to 180 mm adapter should do it.

https://www.chainreactioncycles.com/shimano-front-disc-mount-adaptor-post-to-post-/rp-prod13747

You need a plus 20 mm adapter. A 160 to 180 mm adapter should do it.

No you don't, you need a 160-183mm adaptor, AKA the Hope H mount. See the explanatory text in the top right corner as to why you are having such a bawache trying to find the correct adaptor.

HOPETECH.COM "https://www.hopetech.com/_repository/1/documents/BrakeAdaptorChart2021.pdf"

It looks like shimano dont even do a 180 to 203 adaptor

Yes they do;

Shimano SM-MAF203P/PM are adapters to enable 203 mm disc brake rotors to be used with frames designed for 180 mm ones.

Current common Shimano post-post mount adapters are

160-180 (also 140-160)
160-203
180-203
180-220
200-203
200-220
203-220

Off the top of my head hence the confusion

If you want to check them all out;

https://bike.shimano.com/en-EU/service-upgradeparts/mtb/category/disc-brake-mount-adapter.html

Obviously lots of aftermarket options as well.

what's this I've got arriving tomorrow, then?

https://www.bikeparts.co.uk/products/shimano-adapter-for-post-type-calliper-for-180mm-post-fork-mount-to-203-mm-rotor

I'm doing the same as you OP.

Any 23mm post adaptor should work. Such as:

https://www.chainreactioncycles.com/shimano-xtr-mount-adaptor-front-post-to-post/rp-prod125652?gs=1&sku=sku499636&utm_source=google&utm_term=&utm_campaign=&utm_medium=base&gclid=Cj0KCQiA5OuNBhCRARIsACgaiqVAarx4ZkjKqzCPa1AdsR5yoLB653gHupcka1MxT0ebTe2wg8BtC_MaApgHEALw_wcB&gclsrc=aw.ds

Shimano sm-ma90-f203p/pm

Or a plus 20mm and a few washers

dc1988
Free Member

Or a plus 20mm and a few washers

Odd move unless you just so happen to have one lying around though

Or a plus 20mm and a few washers

I've done this a few times without issues. Despite the standard specs for mounts you sometimes need a washer or two to get everything nicely spaced, especially when mixing brands.

Thanks Everyone

@nedrapier your a star, just ordered that one. Is delivery pretty quick?

Cheers BF

Ok Brake Adaptor Guru's, can you help me out:

From the Scandal thread:
Has anyone actually managed to mate up the Guide RE brake that came on the Scandal with a 180 rotor, and which adaptor did you use?

I've already tried a 160-180 and the caliper doesn't mate up with the rotor correctly.

Guide RE brakes use the old Avid Code style caliper, so you need a set of Avid conical washers inbetween the brake mount and the caliper. The caliper won't fit directly into the mount without them. I'll try find a link to the washers but if you Google avid conical washer you should find them. I think they will only be about a fiver with some bolts included.

https://www.ebay.co.uk/itm/Avid-Bolt-Kit-CPS-Direct-Caliper-Mount-29mm-Stainless-Steel-Bolts-Washers-/193484128360?mkcid=16&mkevt=1&_trksid=p2349624.m46890.l49286&mkrid=710-127635-2958-0

Guide RE brakes use the old Avid Code style caliper, so you need a set of Avid conical washers inbetween the brake mount and the caliper.

I was using the washers as well (as it came with washers originally), but the adaptors seemed wrong and didn't line up the caliper 'straight' on the rotor.

I did try a 160-203 adaptor with a 203 rotor, but there wasn't enough space between the chain & seat stays to then mount the caliper.

Ahh okay, I've just had a look on the On One website and see what you mean about the clearance. Have you tried flipping the 203 adaptor around the wrong way and using a 180mm rotor in there. With the adaptor flipped round it should give you the clearance for the caliper to fit with the washers. (Pushed forward and upwards to clear the seat stay, if that makes sense?)

This thread has now turned into a thread about Guide RE brakes and cps washers half way through, it could confuse a stupid person 😀

Just as well it did. I’ve a set of those to fit to my new frame so I’ve bought the bolts just in case those are the ‘missing’ parts I need to complete the build up.
Excellent random forum work chaps.

Just as well it did. I’ve a set of those to fit to my new frame so I’ve bought the bolts just in case those are the ‘missing’ parts I need to complete the build up.

I haven't really got on with them TBH, the "eBike brake" sounded good, can't beat having too much power - but the reality is they don't deliver what even a pair of old Deore's do.

Just to get back on track to the op's question, squirrelking was spot on, the other options are long bolt, longer bolt, conical washer bollox. For anyone else doing the same go for Hope, it limits the amount of times the threads in your lowers get used if you remove or adjust the caliper regularly, and I think its a more stable platform.