Magura hydraulic rim brake pad change -- instructions please
Andre Jute
Magura HS11 hydraulic rim brakes tonight. Instructions please,
urgently.
I have the factory instructions of course but they don't appear to be
worth shit, and the photographs are too small and too wretched to be
useful.
In particular, do I need to take the wheels out, that is, can I slide
new brake blocks in from the side of the holder, along with the run of
the rim, or do they pop in only perpendicularly from the space now
occupied by the rim?
No doubt more questions will arise as I actually try it.
TIA.
Andre Jute
I'm not a know-all. I don't need to be. I know who to ask.
Clive George
news:618a21e1-5dbb-4065...@y10g2000prg.googlegroups.com...
> I'm going for a big ride tomorrow so I have to change the pads on my
> Magura HS11 hydraulic rim brakes tonight. Instructions please,
> urgently.
>
> I have the factory instructions of course but they don't appear to be
> worth shit, and the photographs are too small and too wretched to be
> useful.
>
> In particular, do I need to take the wheels out, that is, can I slide
> new brake blocks in from the side of the holder, along with the run of
> the rim, or do they pop in only perpendicularly from the space now
> occupied by the rim?
Easiest to drop the wheel clear of the pads, pull them out, push the new one
on.
You can't slide them in from the side, only perpendicular.
If you've got the quick release mount, you can do at least one without
moving the wheel.
Should be a 10 minute job at most.
Peter Cole
Can't help you with the pads but, do you really need to changes them?
One thing I've learned over the years is *never* do major work before a
big ride -- do it before a small ride.
Clive George
news:I7SdndFM1Nxt5ErX...@brightview.co.uk...
S'pose for completeness sake I ought to mention backing off the pad
adjustment screw all the way before removing them - gives a bit more space
to play with, and means new ones will actually fit in.
Andre Jute
Fortified with Clive's instructions, spare brake blocks and tools,
after dinner I approached the bike -- and discovered it was all a
mistake, in fact a compound of two mistakes.
Out in the countryside I was standing atop a hill looking down on the
estuary of the River Bandon where it flows through Kilmacsimon Quay
towards Kinsale. A farmer with whom I have a nodding acquaintance
slowed his tractor to thank me for being considerate in the short
silage season just gone, and shone his headlight on the rims of my
bike. Horrors, they appeared scored! That was the first error.
Not having my helmet light with me, I took off one of my bike lights
and discovered the brake blocks were almost level with the front of
the holder. That was the second error.
Of course I concluded the brake blocks were worn down and ruining my
expensive wheels. Even if new wheel-building were free, which it is
not, I'd want my wheels rebuilt by the guys who built these obviously
very fine wheels, and that means the hassle and cost of sending them
to Germany. Aaargh. I rode home without using the brakes, looking out
for a Range Rover I could kick to death to express my opinion.
***
After dinner, with strong lights rigged, and spare brake blocks and
torque wrench laid out together with cleaning materials, I discovered:
1. The "scoring" is a wear indicator ring on rim. It looked worse than
it should because the black rim has a shiny machined braking surface
and close by the hyperactive reflective band on the Big Apple. That
tractor might as well have shone a light on chrome and asked me to
read fine-print in it.
2. The fingers "holding" the brake blocks don't move towards the rim
with the brake blocks; they are merely guides and at least three
millimetre from the rim. (Easy to understand how I made this mistake.
My last bike with rim brakes was seven years ago, and had V-brakes,
where the whole assembly pivots and moves towards the rim, and I was
hardly very familiar with that because even minor adjustments were
done for me by Joe the Bike; I didn't start doing my own maintenance
until I switched over to roller brakes and disc brakes...)
3. The brake blocks are good, hardly any wear at about 1800km, but in
the retracted position it is hard to see the wear indicator slots in
the blocks because in a fat rim wearing a balloon tyre the overhang
gets in the way; clearances are pretty small on the Utopia when you
fit the fattest wheels and tyres. Peering at it in deep dusk doesn't
help either. At home, with good light, one can by a few contortions
get a more enlightening view.
***
Sorry for the disturbance but I am glad I inspected those brakes and
got a better idea of how they work and fit to the bike and how to
adjust them. It is not something you want to start doing on the road
without the manual, among other reasons because there are several hex
sockets on the brake lever and its fittings, of which only one adjusts
the brake block position. It wasn't the one I thought it was, and my
Topeak Toolbar isn't slender enough to get at the right one, so I've
added a slender extension bar from another toolkit to my travelling
toolpack. I wouldn't have known about the necessity for that either
without this business.
***
I've also minded Peter's admonition to do big jobs -- in which we
should include little jobs done for the first time -- only before
little rides and haven't actually taken the wheels out (a big job at
the rear with a Rohloff and a full-enclosure chaincase) to remove the
brake blocks but I did loosen the calipers and torque them up to
blueprint. I undid the offside front to equalize the space each brake
block is from the rim because the wheel seemed otherwise centred in
the fork, and finding that no great hardship, did the other three as
well.
QUESTION: Instead of removing the rear wheel, does it make sense
simply to unbolt the HSxx caliper each side, remove it, fit new brake
blocks and refit the caliper? It seems like a quicker job than
buggering around removing a hatch in the chaincase, splitting the
chain (maybe not necessary -- I haven't tried this and it isn't
scheduled until the Christmas holidays) and dropping the rear wheel?
Thanks to Clive and Peter for good advice.
***
I don't have the quick release on my Magura HS11 but I'm striking it
from an order to Utopia I'm working on; it's pretty careless design to
make a quick-release that works on only one half the calipers of each
wheel!
Andre Jute
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Andre Jute
> "Clive George" <cl...@xxxx-x.fsnet.co.uk> wrote in message
>
> news:I7SdndFM1Nxt5ErX...@brightview.co.uk...
>
>
>
>
>
Turned out to be unnecessary to change the pads -- see my other
letter, but it does no harm whatsoever to cross all the tees and dot
all the eyes when giving instructions to someone who is doing the job
for the first time.
I found the adjustment screw pretty stiff to move even with a
longhandled automotive type hex key. Even if I could reach it with my
travelling Topeak Toolbar (too fat -- I've already added a slender hex
extension to my toolkit), I doubt I could turn it with such a short
lever. Should I remove the adjustment screws and grease them? I mean,
they aren't perchance all that stands between me and a big splash of
Blood of Magura or whatever the stuff in the pipe is called?
Thanks again.
Andre Jute
You can ride only one bike at a time
Clive George
>3. The brake blocks are good, hardly any wear at about 1800km, but in
>the retracted position it is hard to see the wear indicator slots in
>the blocks because in a fat rim wearing a balloon tyre the overhang
>gets in the way; clearances are pretty small on the Utopia when you
>fit the fattest wheels and tyres. Peering at it in deep dusk doesn't
>help either. At home, with good light, one can by a few contortions
>get a more enlightening view.
I thought it was a bit unlikely that they would be worn out - glad to see
that's the case.
>I don't have the quick release on my Magura HS11 but I'm striking it
>from an order to Utopia I'm working on; it's pretty careless design to
>make a quick-release that works on only one half the calipers of each
>wheel!
Don't think there's much stopping you putting the quick release on both
sides - simply get two kits, not one. You could ask on the Magura forum to
see if it's a bad idea.
OTOH the pads actually last a long time, and adjustment doesn't require
removal, so you could just leave it all bolted up. I think the QR is to let
you get the wheel out with the tyre still inflated - you only need to shift
one side to do that.
Clive George
>I found the adjustment screw pretty stiff to move even with a
>longhandled automotive type hex key. Even if I could reach it with my
>travelling Topeak Toolbar (too fat -- I've already added a slender hex
>extension to my toolkit), I doubt I could turn it with such a short
>lever. Should I remove the adjustment screws and grease them? I mean,
>they aren't perchance all that stands between me and a big splash of
>Blood of Magura or whatever the stuff in the pipe is called?
Nah, they're external to the hydraulic gubbins. You should be able to remove
the lever by unbolting the pivot, and from there get access to remove the
adjustment screw and grease it - which isn't a bad idea. They're a bit of a
pain if they do seize, though nowadays they appear to have a more sensibly
sized hex socket (HS66 and old HS11 or 22 take 2mm).
Andre Jute
> "Andre Jute" <fiult...@yahoo.com> wrote in message
You're talking about the lever reach adjustment on the outside of the
levers, which is probably still 2mm (there's a hex socket screw there
but the handbook says my HS11 don't have reach adjustment --!?!?).
I'm talking about the wear compensation adjustment for the brake block
which is on the inside of the lever, right up close by the lever
blade's root, and done by 4mm hex. One should be able to extract the
grub screw without disassembling anything at all; the question is
whether it attached or bears on anything that can let the hydraulic
liquid loose. (I imagine the brake blocks are moved inwards by simply
screwing the piston deeper into the bore.)
Andre Jute
http://www.audio-talk.co.uk/fiultra/Andre%20Jute's%20Utopia%20Kranich.pdf
Clive George
No, I am talking about the 4mm wear compensation adjustment. On the older
brakes, it was a 2mm hex, hence the pain when it seized. And it's still
external to the hydraulic gubbins - you can take the lever off entirely
safely, and that includes the 4mm adjuster.
Andre Jute
In that case, I'll just back the adjuster out without disassembling
anything else, grease it and fit it back. Thanks. -- AJ