You don't need to be an 'investor' to invest in Singletrack: 6 days left: 95% of target - Find out more
So a friend of mine is building a DH bike, mostly 2nd hand parts etc.
He has some '09 boxxer world cups, like these ones:
[img] http://bikeblogs.blogs.com/.a/6a00d83455d1f269e20120a55c5896970b-300wi [/img]
The forks have an IS brake mount, and he has some newest style Shimano brakes (slx I think) which are post mount, and he's using a 203mm rotor. What friggin adaptor does he need???
Tried this:
[img] http://media.chainreactioncycles.com//is/image/ChainReactionCycles/prod15261_IMGSET [/img]
And the caliper is far too high in relation to the rotor, so the pads would barely touch the rotor when the brake was compressed:
[img] 
[/img]
So he's bought and tried the smaller size adaptor:
[img] http://media.chainreactioncycles.com//is/image/ChainReactionCycles/prod26724_IMGSET [/img]
But that doesn't fit either.
Ok, so does he need specific adaptors for shimano brakes to fit to boxxers, or are there any others that would work?
Having not seen the bike in the flesh I'm a bit baffled. Any help appreciated.
I think the Boxxers have a 200ish mm mount anyway (as you wouldn't run 180mm rotors with those forks anyway) so he just need a IS->PM adapter?
Not being funny but are you sure that's a 203mm rotor? Looks quite wee in the pic
That was my first question to him too, Northwind. But it is:
[img] 
[/img]
Scaled, that sounds logical to me. Don't most adaptors come designed for a specific sized rotor though? Or can you buy generic PM>IS ones?
Older boxxers had a boxxer specific mount and hence adaptor, pretty sure it only changed to IS standard in 2010 so likely you need the boxxer adaptor not a standard IS adaptor.
He's tried both the 203 and 185 boxxer-specific adaptors STATO. Hence the confusion. Not really sure what other options there are tbh? Surely other aftermarket boxxer adaptors (Hope etc) will be same dims as the avid ones?
Get rid of the Avid mounts, get some Shimano or Superstar ones - win
It obviously changed pre 2010 then, so standard IS mounts it is. Or have you tried those too?
It's not standard IS, Boxxer specific mounts are needed
hasn't he just got the mount the wrong way round?
The 'short' arm is supposed to be at the top.
Only tried the boxxer-specific mounts as far as I know. Maybe it is a regular IS mount? It definitely changed in 2010, though I thought they went from boxxer-specific mount straight to regular post mount.
I will get him to try a regular IS 203 mount, cheers for the input fellas.
Nah, the mounts have up arrows on them, he's definitely been putting them on the right way.
Legend - tried both 203 and 185 boxxer-specific mounts.... I thought they should have worked too.
EDIT: Nevermind 😛
Legend - tried both 203 and 185 boxxer-specific mounts.... I thought they should have worked too.
Yes, Avid mounts, which aren't the same as normal ones iirc due to all the tri-align crap that Avid use
I might still have a boxxer 203 mount somewhere, it'll be Shimano or Hope... Can have a rummage if you like but I might have given it away
Ok, I didn't realise avid mounts were any different to regular mounts. I've never used avid brakes. I'll let him know to try a different brand.
Northwind, if you've got one knocking about that could be really useful!
I'd have thought that using an avid mount without "all that tri-align crap" between brake and mount would leave the pads too low, not too high
[s]FWIW, I think those mounts/adaptors are for fitting a post-mount brake to a IS fork. My small brain can't work out how that would differ - have you tried them upside down[/s] ? (deleted due to idiocy)
Avid adaptors are the same as any other. The cps washers are accounted for in the caliper.
I thought as much. So if we are saying that all boxxer-specific->PM 203 adaptors are the same dimensions, why isn't it fitting?
I'm still thinking that trying a regular IS>PM adaptor might be a winner. I think the spacing of the bolt holes is the same (51mm)?
I can't remember when boxxer went IS but it does seem like the logical next thing to try. Maybe take some comparative measurements of the tabs if you have an IS fork to compare to.
I have some other IS forks, and appropriate mounts, lying around so I will get some of them to him to have a try. Cheers for your comments guys.
This is the one you want
As a bonus it's much lighter than the one you've got.
That mount you show in the first picture looks a lot more like a regular IS to 180 Postmount adapter (I've just been out to look at my collection) Boxxer to 203 Postmount are much more squat at the upper end.
Oh and that fork is great just make sure you strip them and check the bottom of the legs where the circlip goes to hold the innards in. They're getting on a bit now and mine sheared at the bottom of the damper leg when out in Morzine last time when the last couple of mm below the circlip fell off. No accident caused but it was 200 Euros for the last stantion in town to get me running again.
Speeder... Very Cheap at Halfords - £5.40
Got to love Halford's description:
The Hope Disc Brake Mount to Boxxer pre-2010 has been built with precision and is comparatively lightweight. It’s [u]ideal[/u] for both Mountain and [b][u]Road Bikes[/u][/b] and bolts are included.
How does a boxxer affect the steering on a roadbike?
Just realised that from the op that this:
[img] http://media.chainreactioncycles.com//is/image/ChainReactionCycles/prod15261_IMGSET [/img]
isn't the same mount as shown here:
[img] [/img]
Looks like the wrong mount has been sent.
It should sit like this:
[img] 
[/img]
Can't find my mount, sorry- might have given it away with the forks.
ive got a boxer mount somewhere, not sure if its the same as the others, will look tonight
Hmm, cheers legend, his definitely does look different. I'm seeing him tonight so I'll double check what he's got and tried so far. Thanks again for the advice!
Speeder - that's good advice, cheers. You managed to shear off a stanchion leg though?? Or did I read that wrong? I'll give them a check over regardless.
It's just the last bit of the stantion leg below the internal circlip that holds the damping gubbins in, about 3mm. At the bottom of every stroke when the front wheel becomes airborn the circlip puts some load into the seat and as it's aluminium there's going to be some fatigue over time. If the circlip happens to have a slightly sharp edge to it, it can dig into the groove and make matters worse. It's not as far as I know a universal problem but I believe I'm not the first to have suffered it, at least the shop weren't surprised.
Can't fault the forks otherwise, I love mine.
Ahh I see what you mean. Not a huge amount you can do about that then, just regular inspections/lower service. Good to know though!