Magura Rim Brakes mounting issue (1995 Model HS33)

Hi,

Anyone have any wisdom on these rim brakes from hell Magura 1995ish HS33 (John Tomac Edition)? Would appreciate some advice on the mounts. They have a fixed “Elbow” that presses against the frame, these apparently can be moved but I cant see how, they look to be just a blank rivit with no means of adjustment. Does anyone know how to remove the elbows?

Spent the last 3 nights cleaning, bleeding and now trying to mount the bloody things. They look trick and work great (if you can ever get them adjusted), but if i cant get em sorted tonight I’m switching to Vees.

IIRC – you undo the 5mm Allen bolt at the top that threads into the elbow, and if the elbow is really tight you can use a 10mm spanner (on the flats) to move it (you can also use the spanner to hold the elbow in place whilst you re-tighten the 5mm Allen bolt)

The elbow isn’t fixed, it might just be really tight in there! I think they were a pretty tight interference fit to stop them moving when braking.

I had a set of HS33 race lines on my trials bike circa ‘97, and that worked for me!

A

The elbow has some ‘spiky’ splines that allow it to be rotated once the bolt is undone but stay in place when done up.

If you are still having troubles, ring the guys at Tarty Bikes and they can talk you through it.

Thanks Andy,

I see what you what mean, there is a 5mm bolt that screw into the other end of the elbow which is used to secure the brake booster. But this 5mm borlt doesn’t seem to be used to secure the elbow, the elbow seems to be secured via ridges around the bolt – so there is no way it can be twisted. Should the elbows be loose when not the brakes are not fully mounted?

yes, the elbows can be lifted off, rotated and then pressed back onto the splines.

Great, thanks for the quick responses guys. So it looks like the elbows on my mounts have seized up, I’ll try and tap em out.

I wouldn’t tap/hit them as the metal is quite soft (guess how I know!)
Best way I found is put the bracket in a vice and use a 10 mm spanner on the flats of the elbow. Will need a bit of force, but will go eventually.

should look like this.

the top bolt (brake booster) is attached to the elbow.

Good luck – one of the most annoying components to set up iirc – mostly due to that elbow.

The top bolts hold the cylinders in place so should be tightened before the bottom. Bottom bolts then tighten after setting the height. One side is quick release so you can get the wheel off easily.

As said above they are a bit fiddly to set up but once set, you just use the bottom bolts to remove/clean/service and won’t need to re alight the pads again.

Awesome brakes. I miss mine. Off to find my Tricks and Stunts DVD now…

Thanks for the tips fellas, i;m going to have another go at them tonight. I also need to re-bleed the rear (did it the other night and got covered in mineral oil as a syringe popped off when injected new oil – thank god they don’t use DOT fluid).

Things will be much easier if i can set the elbows adjusted to fit the frame, and thanks for the tip on setting the booster bolts first – should help me get them dialed in.

And just to confirm to everyone they are very fiddly to fit. Had a few rage fits trying to set em up!!

Looking forward to HS-33 install session this weekend, they are definitely one of the fiddliest components to install. Might have to bleed them, rear has never been bled and they were bought over 15 years ago.

The spline bit of the elbow / horn also has a taper so that is part of why they are stuck. As mentioned, a good twisting will get them moving. I think the tapered bit might be steel, so removing the brake bits bits and warming the aluminium bracket with a hairdryer might free them (aluminium will expand more).

If you look at the photo up there ^ you can also see that the clamps are offset. The whole clamp can be swapped LH / RH to reverse the offset and move the brakes inboard / outboard by a larger amount. Be warned – swapping the clamps also means starting from scratch with all the elbow / booster settings and probably deciding you preferred it in the original setting anyway 🙂

I really don’t miss using those brakes…….

Be careful how you remove the elbow, it will most likely be seized in with galvanic corrosion – soak it with plus gas or suchlike

ok, question: should the elbows be loose(ish) before mounting onto and tightening the booster bolts?

Mine have corrsion as mentioned above and aint budging – I just assumed this was normal as the splines indicated (to me) that they are mounted with some force to keep them in place (not by the bolts)

Twisting has been suggested but wouldn’t this strip out the mount hole?

Picture of the elbow and splines.

Or you could replace the brackets with the newer Evo2 brackets – makes set up a lot quicker and easier.
Magura Evo2 Brake Adaptor

Thanks for the link, I would go for the EVO2 mounts if it was a vanity(?) build but its meant as a commuter/winter hack. If I spend anything on the bike it will go on a set of V brakes.