Hydraulic rim brakes?

[Duncan Smith]

On Oct 23, 10:46 am, "Dave Larrington" <[email protected]>
wrote:
> Innews:[email protected],
> Duncan Smith <[email protected]> tweaked the Babbage-Engine to tell
> us:
>
> > Are Magura HS-33 suitable for 700c rims also (web site only shows MTB
> > forks)? If so, they could be just what I'm after for the winter...
>
> As long as the blocks are in the right place, then yes. I had them on my
> Kingcycle - 369 front and 540 rear.
>
> > Has any one ever had a failure on their disc brakes, fitted a front
> > Avid-7 to the MTB about month ago - was working a treat.. Turned the
> > bike upside down to do some work on the rear mech, and when I turned
> > it back up again the front brake lever had full travel down to the
> > bars without any braking action - no sign of a leakage, pads still
> > intact, etc.. Weird!
>
> I put a new Hope disc on the front of the Speedmachine a few months ago. It
> did the Cheddar Gorge 300, 300 well-laden km from Larrington Towers to Paris
> and the first 400 km of PBP. Then I suffered a moment of brain fade and
> fell into a ditch. No sign of damage or leakage, but it flat refused to
> work afterwards. I bled it on returning home and it's been fine ever since.
> Colour me baffled.
>

Thanks all, sounds like I need a bleed kit (or maybe I'll let the LBS
do it). Is it a difficult/messy job to bleed the brakes, do I have to
change the fluid at the same time? Avid sell a kt with two syringes -
would that be the best bet or can it be done without?

Looking at the Magura rim brakes, I'm assuming the booster is the
horseshoe shaped metal bit that adds rigidity. Not sure whether that
might make fitting tricky over the large fenders and pannier rack top
stays - maybe the booster is optional/removable?

Many thanks,

Duncan

 

[Paul Boyd]

Duncan Smith said the following on 23/10/2007 11:04:

> Thanks all, sounds like I need a bleed kit (or maybe I'll let the LBS
> do it). Is it a difficult/messy job to bleed the brakes, do I have to
> change the fluid at the same time? Avid sell a kt with two syringes -
> would that be the best bet or can it be done without?

Ah - now you're asking! Ask five people how to bleed brakes and you'll
get six strongly held opinions!

FWIW, with Shimano brakes I use the "big syringe at the caliper" method
and catch the fluid coming out of the reservoir in a jar or wrap an old
rag around the lever. Works a treat, and I only had to do it once when
I first fitted the brakes. Just make sure the pads are removed in case
of any accidents.

--
Paul Boyd
http://www.paul-boyd.co.uk/

 

[Clive George]

"Duncan Smith" <[email protected]> wrote in message
news:[email protected]...

> Are Magura HS-33 suitable for 700c rims also (web site only shows MTB
> forks)? If so, they could be just what I'm after for the winter...

They fit on pretty much anything with standard canti/V brake bosses.

cheers,
clive

 

[Clive George]

"Duncan Smith" <[email protected]> wrote in message
news:[email protected]...

> Looking at the Magura rim brakes, I'm assuming the booster is the
> horseshoe shaped metal bit that adds rigidity. Not sure whether that
> might make fitting tricky over the large fenders and pannier rack top
> stays - maybe the booster is optional/removable?

I'd fit the booster if at all possible. The brakes don't have a cable
providing an opposing force to the pads, so if you don't have a booster
you'll see things bending when you squeeze hard.

The booster sits in about the same place as the pipe linking the two slave
cylinders. I've never had a problem with mudguards and racks intefering with
them - it goes over the mudguard and under the rack stays.

cheers,
clive

 

[Tim Hall]

On Tue, 23 Oct 2007 10:04:27 -0000, Duncan Smith
<[email protected]> wrote:


>Looking at the Magura rim brakes, I'm assuming the booster is the
>horseshoe shaped metal bit that adds rigidity.


Correct.

> Not sure whether that
>might make fitting tricky over the large fenders and pannier rack top
>stays - maybe the booster is optional/removable?
>

I've got mine going over big mud guards (fenders) without any problem.
The pannier rack fits over the top of the booster. The booster is
removable but I wouldn't advise it. I can get my seat stays to bend in
an alarming manner if I use the brakes with it off.



--

Tim

fast and gripping, non pompous, glossy and credible.

 

[Tony Raven]

In article <[email protected]>,
[email protected] says...

>
> I've got mine going over big mud guards (fenders) without any problem.
> The pannier rack fits over the top of the booster. The booster is
> removable but I wouldn't advise it. I can get my seat stays to bend in
> an alarming manner if I use the brakes with it off.
>


Wot 'e said

--
Tony

" I would never die for my beliefs because I might be wrong."
Bertrand Russell

 

[M-gineering]

Duncan Smith wrote:

> Looking at the Magura rim brakes, I'm assuming the booster is the
> horseshoe shaped metal bit that adds rigidity. Not sure whether that
> might make fitting tricky over the large fenders and pannier rack top
> stays - maybe the booster is optional/removable?

Current MAgura's have a steel horseshoe which goes between fork and
brakes. It has two holes where you plug the brakebrackets in, to prevent
them splaying outward. The horsehoe can be substituted with the old
style brakebrackets with the L-shaped pins which catch behind the
forkblades.

Sometimes you run into problems (eg 700c wheeld bikes with narrow forks)
where the horseshoe is too wide and too big (hitting the downtube),
where the old style (with lots more adjustement) will fit fine.

the brakebooster is optional and goes on at the front of the brake

--
/Marten

info(apestaartje)m-gineering(punt)nl

 

[Duncan Smith]

On Oct 23, 12:05 pm, Tim Hall <[email protected]> wrote:
> On Tue, 23 Oct 2007 10:04:27 -0000, Duncan Smith
>
> <[email protected]> wrote:
> >Looking at the Magura rim brakes, I'm assuming the booster is the
> >horseshoe shaped metal bit that adds rigidity.
>
> Correct.
>
> > Not sure whether that
> >might make fitting tricky over the large fenders and pannier rack top
> >stays - maybe the booster is optional/removable?
>
> I've got mine going over big mud guards (fenders) without any problem.
> The pannier rack fits over the top of the booster. The booster is
> removable but I wouldn't advise it. I can get my seat stays to bend in
> an alarming manner if I use the brakes with it off.
>

Great thanks, turns out the LBS have just put in their first order for
these, so I shall look forward to picking a rear one up - good
solution because I was after a fit and forget brake that would operate
well throughout the winter(s) but don't have sliding dropouts for a
disc.

Many thanks,

Duncan

 

[Andrew Price]

On Tue, 23 Oct 2007 08:14:09 -0000, Duncan Smith
<[email protected]> wrote:

>Are Magura HS-33 suitable for 700c rims also

Yes.

 

[Rob Morley]

In article <[email protected]>, Clive George
[email protected] says...

> I'd fit the booster if at all possible. The brakes don't have a cable
> providing an opposing force to the pads, so if you don't have a booster
> you'll see things bending when you squeeze hard.
>
Eh?

 

[Peter Clinch]

Membrane wrote:
> Hydraulic rim brakes, what's the point (for on road use)?
>
> Not many of them to be found, so maybe that part answers the question,
> but I fail to see any real advantage. Never having ridden a bike that
> has them, I imagine that they are potentially lighter to operate (one
> finger braking), but it's not like that solves a problem.
>
> The drawbacks are easy to imagine (more expensive, heavier, changing
> fluids every so often, harder to maintain etc.).

I had compiled pretty much exactly that list of pros and cons when I
decided not to get them on my Streetmachine when I originally bought it.
The supplied V brakes would lock the wheels, after all...

Time passed, and while Roos was auditioning various 'bents I tried one
that didn't impress in almost any way /except/ for the brakes, which
turned out to be HS-11s and a delight to use. She decided on her new
bike and ordered it with hydraulic discs, and a combination of
brake-envy and having been very impressed by my day with Maguras I got
some HS-33s (my bike would need a new fork at Mucho £££s to take discs,
so discs were out). That upgrade has been a case of Absolutely No
Regrets at all: they're just fundamentally better and nicer in use than
the rim brakes. Smoother, practically zero maintenance, hardly any
degrading between fettles and you can still do stuff like change gear at
the same time as apply full power braking.

I think you've got to use them to appreciate exactly how that adds up to
a Big Win, but I certainly like mine a *lot* and wish I'd ordered them
fitted in the first place.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email protected] http://www.dundee.ac.uk/~pjclinch/

 

[Clive George]

"Rob Morley" <[email protected]> wrote in message
news:[email protected]...
> In article <[email protected]>, Clive George
> [email protected] says...
>
>> I'd fit the booster if at all possible. The brakes don't have a cable
>> providing an opposing force to the pads, so if you don't have a booster
>> you'll see things bending when you squeeze hard.
>>
> Eh?

The pads push against the rim - what provides the opposing force? On Vs and
cantis, it's the cable which provides most of it, with a small contribution
from the brake bosses (levers probably tell you the relative magnitudes). On
hydraulics, there isn't that cable pulling them in, so there needs to be
something else providing that force. On the original maguras, there were
little L-shaped things which hooked onto the fork legs. Unfortunately that
was off centre, so the pistons had an alarming tendancy to twist the
stays/move the bosses out if you squeezed hard. Stick the booster on, and
that now takes the force, and it all stops bending quite so much.

Dunno how the new mount Marten (?) mentioned fares though - not seen one of
those.

cheers,
clive

 

[Paul Boyd]

Clive George said the following on 24/10/2007 11:53:

> The pads push against the rim - what provides the opposing force? On Vs
> and cantis, it's the cable which provides most of it

Eh? The cables on the V-brakes on my tourer aren't providing much
opposing force then - they're quite capable of splaying out the bosses
by flexing the forks or seat-stays. The leverage between the cable
attachment and the block is greater then the leverage between the block
and the boss. Cable pulls the top in, the brake arm effectively pivots
about the block and pushes the boss out.

--
Paul Boyd
http://www.paul-boyd.co.uk/

 

[Clive George]

"Paul Boyd" <usenet.is.worse@plusnet> wrote in message
news:[email protected]...
> Clive George said the following on 24/10/2007 11:53:
>
>> The pads push against the rim - what provides the opposing force? On Vs
>> and cantis, it's the cable which provides most of it
>
> Eh? The cables on the V-brakes on my tourer aren't providing much
> opposing force then - they're quite capable of splaying out the bosses by
> flexing the forks or seat-stays. The leverage between the cable
> attachment and the block is greater then the leverage between the block
> and the boss. Cable pulls the top in, the brake arm effectively pivots
> about the block and pushes the boss out.

Mmm, yes, so it is.

Oh well, bang goes that theory then. I still think it's got some point, but
maybe not as much as I'd thought. Still, take a look at maguras bending
stays/bosses - it's enough to make one want to fit a booster.

cheers,
clive

 

[Rob Morley]

In article <[email protected]>, Clive George
[email protected] says...

> The pads push against the rim - what provides the opposing force? On Vs and
> cantis, it's the cable which provides most of it, with a small contribution
> from the brake bosses (levers probably tell you the relative
magnitudes).

You didn't do well in physics at school, did you?

 

[Clive George]

"Rob Morley" <[email protected]> wrote in message
news:[email protected]...
> In article <[email protected]>, Clive George
> [email protected] says...
>
>> The pads push against the rim - what provides the opposing force? On Vs
>> and
>> cantis, it's the cable which provides most of it, with a small
>> contribution
>> from the brake bosses (levers probably tell you the relative
> magnitudes).
>
> You didn't do well in physics at school, did you?

Disturbingly well actually - but see my other post

cheers,
clive

 

[Simon Brooke]

in message <[email protected]>, Duncan
Smith ('[email protected]') wrote:

> Are Magura HS-33 suitable for 700c rims also (web site only shows MTB
> forks)? If so, they could be just what I'm after for the winter...

They are, yes. Sadly, they aren't available any longer with levers for drop
bars. Does anyone know where to get hold of cable-operated hydraulic
cylinders? I've seen them on a tandem, but don't know what make they were.

--
[email protected] (Simon Brooke) http://www.jasmine.org.uk/~simon/

<p>Schroedinger's cat is <blink><strong>NOT</strong></blink> dead.</p>

 

[Simon Brooke]

in message <[email protected]>, Duncan
Smith ('[email protected]') wrote:

> On Oct 23, 10:46 am, "Dave Larrington" <[email protected]>
> wrote:
>> Innews:[email protected],
>> Duncan Smith <[email protected]> tweaked the Babbage-Engine to
>> tell us:
>>
>> > Are Magura HS-33 suitable for 700c rims also (web site only shows MTB
>> > forks)? If so, they could be just what I'm after for the winter...
>>
>> As long as the blocks are in the right place, then yes. I had them on my
>> Kingcycle - 369 front and 540 rear.
>>
>> > Has any one ever had a failure on their disc brakes, fitted a front
>> > Avid-7 to the MTB about month ago - was working a treat.. Turned the
>> > bike upside down to do some work on the rear mech, and when I turned
>> > it back up again the front brake lever had full travel down to the
>> > bars without any braking action - no sign of a leakage, pads still
>> > intact, etc.. Weird!
>>
>> I put a new Hope disc on the front of the Speedmachine a few months ago.
>> It did the Cheddar Gorge 300, 300 well-laden km from Larrington Towers
>> to Paris
>> and the first 400 km of PBP. Then I suffered a moment of brain fade and
>> fell into a ditch. No sign of damage or leakage, but it flat refused to
>> work afterwards. I bled it on returning home and it's been fine ever
>> since. Colour me baffled.
>>
>
> Thanks all, sounds like I need a bleed kit (or maybe I'll let the LBS
> do it). Is it a difficult/messy job to bleed the brakes, do I have to
> change the fluid at the same time? Avid sell a kt with two syringes -
> would that be the best bet or can it be done without?

Depends on the make. IME Heyes are total pigs, Hopes are easy. Never tried
Maguras. As to changing the fluid, yes if it's been in there more than a
couple of years, no otherwise.

--
[email protected] (Simon Brooke) http://www.jasmine.org.uk/~simon/


... a mild, inoffensive sadist...

 

[Duncan Smith]

>
> Smith ('[email protected]') wrote:
> > Are Magura HS-33 suitable for 700c rims also (web site only shows MTB
> > forks)? If so, they could be just what I'm after for the winter...
>
> They are, yes. Sadly, they aren't available any longer with levers for drop
> bars. Does anyone know where to get hold of cable-operated hydraulic
> cylinders? I've seen them on a tandem, but don't know what make they were.
>

Afraid not, I got around problem by replacing the drop bars with some
North Road style 22.2mm ones. Thorn do some 22.2mm drops that could
help you out, but they're about £100 http://www.sjscycles.co.uk/category-Drop-Handlebars-(Other)-230.htm

Avid do a totally cable operated disc brake, but it's pretty lame
compared to the Juicy-7s IMHO

When I fitted the HS-33s and set the 2mm gap between pads and rim the
lever had to be pulled right back to the bars to hit the biting
point. Using the turbo adjuster to dial the pads in so they're almost
touching the rims has made them usable - not sure how they'll cope
when the pads wear down, we'll see. Good brakes though, lock the rear
with a single finger - I like that!

Duncan

 

[Peter Clinch]

Duncan Smith wrote:
>
> Good brakes though, lock the rear
> with a single finger - I like that!

And only if you really /want/ to lock them, which is even better, and
change gear at the same time...

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net [email protected] http://www.dundee.ac.uk/~pjclinch/