Boxxer brake mounts, colour me confused...

desmojen

So I thought I knew that the Boxxer used to have its own special brake mounting, hence all the Boxxer mount adapters available out there.

I am building an 07 Glory up, and have an 05 Boxxer on it, which had an adapter for a post mount brake already on it. The brakes I have coming for it are Hope Mono M4's and are the black ones with gold piston covers (not sure of year on those). They come in an IS mount flavour. So in the spirit of testing and experimentation, I just tried to fit a spare M4 of the same type that I already have - and it fits! I will still need an adapter to run the big discs, but it looks to me like I can simply use an IS +40 from the Hope range.

So what's the deal? Is the infamous Boxxer mount something from before my forks, or am I missing something?

Jen.

nicklouse

yes the boxer mount holes are spaced the standard 51mm apart and are the standard size but they do not have the same relationship to the axle axis.

So you current fitted brake will not work with any of the standard disc sizes.

desmojen

Thankyou Nick, that explains it There is an adapter available from Shimano, so I can get the set up to work if I use that.
While on the subject of Boxxers, what is the idea behind the dropped top crown? My fork has this, and it leaves a fair section of stanchion sticking up above it. I don't have a flat crown for it, but just wondered what the advantage is with the dropped one, if any?

Jen.

nicklouse

it allows for frames with taller head tubes.

you may need to get a flat crown if the clamps are too close together.

check what it says in the manual.

downloadable somewhere on Srams webby.

here it is.

http://www.sram.com/sites/default/files ... nglish.pdf

How you interpret para. 1 is down to you.