Setting up problems with Magura HS33 brakes

Jim Lyon

Retro Newbie
Hi!
I picked up a set of Magura HS33 brakes ( front & rear, with black calipers) off ebay, in order to uprate my first MTB, a Trek 820 ( & while I'd fitted better tyres & dirt gearing, the benefits I got from that were lost with the brakes never really being up to it, not matter what different variations of canti brakes I tried - hence me buying the Maguras ).
For the moment, I've fitted a new set of Magura grey brake blocks front & rear, tidied up various bits like longer screws to fit the thicker brake booster that came with it ( bronze coloured BETD ), as they were no longer "in safety", rerrouted the cables & cut to length, filled & bled the systems with Magura "Blood" hydraulic oil.
The non standard wheel rims I.m using are slightly thinner @ 25.5. m.m. wide, & the red TPA screws are wound out, fully anti clockwise. According to Magura's literature, the gap between the brake blocks & the wheel rim should be 2 m.m., but no matter what I do (yes, it's a fiddly systyem to set up ! ), I can only approach that by moving the calipers as far into their clamps as I can get them to go (e.g. light tap with a rubber hammer ! ) & toeing in the caliper clamps ( beyond the vertical ), but the amount I do that is limited by the adjustment slot @ the bottom of the BETD brake boosters.
While the brakes do work, to my way of thinking, I'm getting too much lever travel before the brake blocks contact the wheel rim ( the back is just about acceptable as I tend to run the back slack in order to get a soft application of back brake in slippery conditions where there's less traction. However, I tend to use the front more for emergency situations, for which I like the lever a lot further forward, so that I can get better feel through my finger tips, rather than the middle of the finger. I also use harfer brake pads on the back [ no harder than grey] & soft on the front for better control [ Koolstop red or better]. - Lever movement on the back is just over 1", & while the front is about the sme, I'd really like to halve that).
Apart from that, if I turn the red TPA screw clockwise, then the levers get a LOT slacker. Also, if this is what I'm getting with new brake blocks, the situation will only get worse as the brake blocks wear !
Considering that the original Magura brake blocks are a little skinny, does anybody know if it's possible to get a softer thicker block from another source?

Cheers,
Jim
 
the mounts can be run on either side for tighter/wider clearence. they are sort of L shaped, so one way the get the piston closer to the wheel and the other way, they move them away.
 
hoegaardenadds1":2e3l7f5y said:
the mounts can be run on either side for tighter/wider clearence. they are sort of L shaped, so one way the get the piston closer to the wheel and the other way, they move them away.

Well, I feel a complete dork for not spotting that one ! :oops:
But, having now done that, it's cured the problem. So, thanks for sorting me out - much appreciated ! :D :)
 
The blocks should move as soon as you pull the lever.
They do require routine bleeding to keep them in good working order.
Back the adjuster knob off all the way and then bleed them , they will work much sharper.
 
Benandemu":gw4y2b26 said:
The blocks should move as soon as you pull the lever.
They do require routine bleeding to keep them in good working order.
Back the adjuster knob off all the way and then bleed them , they will work much sharper.

JL - Thanks for that, I 'll bear it in mind.
Having upgraded from cantis ( & though I'd improved them with thicker wires & softer brake blocks, @ the end you can only do so much with them ), with the HS33s, @ the moment I've got Koolstop reds in the front & Magura greys in the back, I'm still enjoying the benfits of the extra braking power. ! :D
 
I disagree about routine bleeding. If you have ANY leakage, something is wrong and needs attention - even perhaps just a hose union that needs to be nipped up. I have a set that have run unchanged since 1998 on one bike...including flights, two years stay in Singapore (temperature 32C) and weekly riding.

Most people find that Maguras are 'fit and forget' and the only maintenance needed is to snap in replacement pads.
 
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