Probably a stupid b...
 

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Probably a stupid brake adaptor question

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My frame is post mount 180mm, in that I use a 180mm rotor and no adaptor.

I want to try a 203mm rotor, but it's harder than I expected to find which shape adaptor I need.

Shimano caliper if that matters.

Anyone point me in the right direction please?


 
Posted : 06/08/2023 5:46 pm
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Hope


 
Posted : 06/08/2023 5:48 pm
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Uber bikes have a good video to explain it.


 
Posted : 06/08/2023 5:53 pm
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I think Hope H mount is +23mm or you can use a normal +20 adapter and add a couple of extra washers.


 
Posted : 06/08/2023 5:54 pm
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This is the Shimano one that I use

https://www.biketart.com/products/shimano-post-mount-disc-brake-adapter?variant=40810304438451


 
Posted : 06/08/2023 6:06 pm
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I've got a Hope H mount which is 180 - 203 for sale in the classifieds, £10 posted if you're interested

Cheers

Carlos


 
Posted : 06/08/2023 9:42 pm
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Any old +20 adapter will do it. If the spacing isn't quite right you can add an m6 washer or two to space it out. They're a fiver on eBay or if you have biking mates it is the sort thing that someone will have in the spares box


 
Posted : 06/08/2023 10:13 pm
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Yes, you just need a generic +20 mm adapter. The one that Tracey linked to should work fine. However, I prefer ones where the adapter bolts to the frame, then the caliper bolts to the adapter using separate bolts. It's a minor thing, but it's easier to replace the adapter if you strip a bolt than having your frame or forks helicoiled.


 
Posted : 07/08/2023 2:12 am
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I run 200mm and 220mm rotors, no problems finding adapters, but if you've already bought a 203mm I'd go Hope +23 all day long, not +20 with washers, that's a bodge in my book, some of those Uberbike adapters have sod all in the way of substantial material around the holes, they're like a balancing beam for your caliper, terrible design choice, Hope ones have a really good platform to sit the caliper on, really good product with a nice touch of recessing the hole so you don't need a low profile bolt when running bigger 4 pot calipers.


 
Posted : 07/08/2023 12:00 pm
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Washers aren't a bodge. Even using the "correct" adapter you sometimes need a washer to get the pads nicely positioned.


 
Posted : 07/08/2023 12:05 pm
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Depends, bog standard cheap nasty stamped washer that's roughly 1.5mm found in your spares tub is a definite bodge, CNC'd titanium I'll give you a pass, but there's a reason +23mm adapters exist.
Never had to shim out correct stuff since I.S calipers, Guess I'm lucky.


 
Posted : 07/08/2023 12:20 pm
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The Shimano adapters are decent quality. Shimming them with a washer won't be a problem.


 
Posted : 07/08/2023 1:15 pm

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