Hydraulic rim brakes?

"Membrane" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Hydraulic rim brakes, what's the point (for on road use)?

At the risk of sounding repetitive, given we had a thread on this subject
not very long ago at all, the point is they're really great brakes to use
and own.

Quoted message said:

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 ones I've got (HS66, HS11 (or 22?)) aren't really lighter to operate.
HS33 may be better in this regard. The feel is actually rather different,
reminiscent of Citroen brakes - pull the lever till the pads hit the rim,
then the lever mostly stops moving as you apply more pressure to it.

Quoted message said:

The drawbacks are easy to imagine (more expensive, heavier, changing
fluids every so often, harder to maintain etc.).

However some of your drawbacks are about as far from the mark as it's
possible to be :-)

Price, yes. Weight, dunno. Changing fluids every so often, harder to
maintain? Nope, that's where they beat every other rim brake hands down.
They're a closed system, so don't need the fluid changing - the ones on our
road tandem haven't been opened since I bought them 10 years ago. There's no
cables to wear, snap, stick or otherwise cause hassle. Pad changing is
wonderfully easy : wind back the adjuster at the lever, pull the old pad
off, pop the new one on - no tools required. No need to realign the pads in
their many degrees of freedom, toe in, etc - they just go on, since the
slave cylinder has all that adjustment done on installation, once.

The sets I have are on tandems. The big winner there is no cable stretch on
the back, but they're very good brakes too, and the aforementioned
maintenance advantages have become apparent over the years.

Would I get another set? Depends how the Vs on my wife's birdy last - if
they start giving me hassle, I'll put a set of HS33s on there. My road solo
uses dual pivots, which give me all I need, and they're not compatible with
ergo/STI anyway. But I did persuade at least 4 other tandem teams to get
HS66s, and I've not been lynched yet :-)

cheers,
clive

Clive George said:

They're a closed system, so don't need the fluid changing

Can you describe how the system differs from the ones found on
motorbikes or cars, how is it that the fluid doesn't need changing?

--
Membrane

In article <[email hidden]>, Membrane
[email hidden] says...

Quoted message said:

Clive George said:

They're a closed system, so don't need the fluid changing

Can you describe how the system differs from the ones found on
motorbikes or cars, how is it that the fluid doesn't need changing?

They use mineral oil rather than conventional brake fluid, and the
system isn't open to the atmosphere. Car systems use a hygroscopic
fluid, and the reservoir is vented.

"Membrane" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Clive George said:

They're a closed system, so don't need the fluid changing

Can you describe how the system differs from the ones found on
motorbikes or cars, how is it that the fluid doesn't need changing?

Depends - how much do you know about motorbike/car brakes?

There's only one make of hydraulic rim brakes - magura. The system is
incredibly simple : pistons attached to the pads and brake lever, hydraulic
fluid under the pistons and in the pipes. It's not designed to get hot, so
there's no need to cope with fluid expansion (and yes, experience proves
this to be correct), which means the reservoir you see on open system
circuits which is exposed to the atmosphere isn't necessary. So it's a
sealed system. The fluid is a mineral oil based one (somewhat like citroen
LHM), which doesn't appear to degrade with time. It's not hygroscopic
either, unlike DOT fluid (car/motorbike), so even if it were open, it
wouldn't absorb water from the air.

There are closed system disc brakes too - eg hope C2. My very brief
experience with those led me to decide to get open ones for any discs I
have - I did heat the fluid up enough to require adjustment, which is
something I've never had to do with the magura rim brakes on the tandem,
despite getting them really quite hot on big steep descents.

cheers,
clive

Membrane said the following on 23/10/2007 01:39:

Quoted message said:

Can you describe how the system differs from the ones found on
motorbikes or cars, how is it that the fluid doesn't need changing?

Car brakes (except some Citroens) use brake fluid that absorbs moisture.
The brakes Clive uses (and Shimano hydraulic brakes) use mineral oil
that doesn't absorb moisture. The problem with moisture is that it
boils, creates a gas which compresses, so the brakes go spongy.

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

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

Quoted message said:

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.).

Your imagination is too fertile. I have had Magura hydraulic rim brakes
on several of my bikes for years. I haven't had to touch them for
maintenance in all that time unlike the cable rim brakes. There is no
cable to get sticky or rusty and need lubricating or replacing, the
brake blocks on Maguras are so thick it will be ages before they are
worn down and as they wear its a simple twist of the red knob on the
levers to adjust them.

As for use they brake better and more confidently than cable brakes and
unlike cable brakes where you pull the lever and it moves closer and
closer to the bars as you try to brake harder, the cables stretch and
the housing compresses, on hydraulics you pull them in to the
(adjustable) bite point and then increased pressure on the lever without
significant movement increases the braking force.

--
Tony

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

In article <[email hidden]>, clive@xxxx-
x.fsnet.co.uk says...

Quoted message said:

The sets I have are on tandems. The big winner there is no cable stretch on
the back, but they're very good brakes too, and the aforementioned
maintenance advantages have become apparent over the years.

We have them on our tandems and interestingly while nowhere near as bad
as cable stretch there is a definite "hose bulge" equivalent that makes
the rear brake lever much softer than the front.

--
Tony

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

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

Quoted message said:

In article <[email hidden]>, Membrane
[email hidden] says...

Quoted message said:

Clive George said:

They're a closed system, so don't need the fluid changing

Can you describe how the system differs from the ones found on
motorbikes or cars, how is it that the fluid doesn't need changing?

They use mineral oil rather than conventional brake fluid, and the
system isn't open to the atmosphere. Car systems use a hygroscopic
fluid, and the reservoir is vented.

And car brakes can get a lot hotter in use with the potential to try to
boil any water in the fluid.

--
Tony

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

Clive George said:

The fluid is a mineral oil based one (somewhat like citroen
LHM), which doesn't appear to degrade with time. It's not hygroscopic
either, unlike DOT fluid (car/motorbike), so even if it were open, it
wouldn't absorb water from the air.

Interesting, thanks for explaining.

--
Membrane

Paul Boyd usenet.is.worse@plusnet said:

The problem with moisture is that it
boils, creates a gas which compresses, so the brakes go spongy.

It also causes corrosion, which leads to sticking pistons and leaks 🙁

In article <[email hidden]>, Tony Raven
[email hidden] says...

Quoted message said:

In article <[email hidden]>, clive@xxxx-
x.fsnet.co.uk says...

Quoted message said:

The sets I have are on tandems. The big winner there is no cable stretch on
the back, but they're very good brakes too, and the aforementioned
maintenance advantages have become apparent over the years.

We have them on our tandems and interestingly while nowhere near as bad
as cable stretch there is a definite "hose bulge" equivalent that makes
the rear brake lever much softer than the front.

You'd have though they'd make a chunkier hose for longer runs.

Clive George said:

"Membrane" <[email hidden]> wrote in message

news:[email hidden]...

Quoted message said:

Hydraulic rim brakes, what's the point (for on road use)?

At the risk of sounding repetitive, given we had a thread on this subject
not very long ago at all, the point is they're really great brakes to use
and own.

Quoted message said:

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 ones I've got (HS66, HS11 (or 22?)) aren't really lighter to operate.
HS33 may be better in this regard. The feel is actually rather different,
reminiscent of Citroen brakes - pull the lever till the pads hit the rim,
then the lever mostly stops moving as you apply more pressure to it.

Quoted message said:

The drawbacks are easy to imagine (more expensive, heavier, changing
fluids every so often, harder to maintain etc.).

However some of your drawbacks are about as far from the mark as it's
possible to be :-)

Price, yes. Weight, dunno. Changing fluids every so often, harder to
maintain? Nope, that's where they beat every other rim brake hands down.
They're a closed system, so don't need the fluid changing - the ones on our
road tandem haven't been opened since I bought them 10 years ago. There's no
cables to wear, snap, stick or otherwise cause hassle. Pad changing is
wonderfully easy : wind back the adjuster at the lever, pull the old pad
off, pop the new one on - no tools required. No need to realign the pads in
their many degrees of freedom, toe in, etc - they just go on, since the
slave cylinder has all that adjustment done on installation, once.

The sets I have are on tandems. The big winner there is no cable stretch on
the back, but they're very good brakes too, and the aforementioned
maintenance advantages have become apparent over the years.

Would I get another set? Depends how the Vs on my wife's birdy last - if
they start giving me hassle, I'll put a set of HS33s on there. My road solo
uses dual pivots, which give me all I need, and they're not compatible with
ergo/STI anyway. But I did persuade at least 4 other tandem teams to get
HS66s, and I've not been lynched yet :-)

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...

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!

Thanks,

Duncan

Membrane said:

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.).

--
Membrane

My Meridian has Hydraulic brakes while my Hawk has cable.

I prefer the the hydraulic there just smoother, more responsive, take
less effort to apply quicker stopping power.

Breaking just seems more smooth as well.

Weight wise I dunno, can't see that there would be any major
difference from looking at the different mechanisms.

If I had the choice I would go hydraulic, just feel better, the bike
stays more stable specially at breaking at high speed, you don't tend
to get the "Shudder Effect" that you get with cable breaks.

Fikeus

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

Quoted message said:

Clive George said:

"Membrane" <[email hidden]> wrote in message

news:[email hidden]...

Quoted message said:

Hydraulic rim brakes, what's the point (for on road use)?

At the risk of sounding repetitive, given we had a thread on this subject
not very long ago at all, the point is they're really great brakes to use
and own.

Quoted message said:

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 ones I've got (HS66, HS11 (or 22?)) aren't really lighter to operate.
HS33 may be better in this regard. The feel is actually rather different,
reminiscent of Citroen brakes - pull the lever till the pads hit the rim,
then the lever mostly stops moving as you apply more pressure to it.

Quoted message said:

The drawbacks are easy to imagine (more expensive, heavier, changing
fluids every so often, harder to maintain etc.).

However some of your drawbacks are about as far from the mark as it's
possible to be :-)

Price, yes. Weight, dunno. Changing fluids every so often, harder to
maintain? Nope, that's where they beat every other rim brake hands down.
They're a closed system, so don't need the fluid changing - the ones on our
road tandem haven't been opened since I bought them 10 years ago. There's no
cables to wear, snap, stick or otherwise cause hassle. Pad changing is
wonderfully easy : wind back the adjuster at the lever, pull the old pad
off, pop the new one on - no tools required. No need to realign the pads in
their many degrees of freedom, toe in, etc - they just go on, since the
slave cylinder has all that adjustment done on installation, once.

The sets I have are on tandems. The big winner there is no cable stretch on
the back, but they're very good brakes too, and the aforementioned
maintenance advantages have become apparent over the years.

Would I get another set? Depends how the Vs on my wife's birdy last - if
they start giving me hassle, I'll put a set of HS33s on there. My road solo
uses dual pivots, which give me all I need, and they're not compatible with
ergo/STI anyway. But I did persuade at least 4 other tandem teams to get
HS66s, and I've not been lynched yet :-)

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...

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!

Sounds like you may have had some air in the system that percolated to
the caliper while the bike was upside down and got trapped there.
Pulling the lever will then be compressing the air more than moving the
cylinder. BICBW

--
Tony

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

Tony Raven said the following on 23/10/2007 08:29:

Quoted message said:

We have them on our tandems and interestingly while nowhere near as bad
as cable stretch there is a definite "hose bulge" equivalent that makes
the rear brake lever much softer than the front.

You want some bling braided hose for that :-)

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

In article <[email hidden]>,
Duncan Smith
[email hidden] says...

Quoted message said:

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!

Air from the reservoir has got into the 'active' fluid. If you're lucky
it will right itself (air will slowly work its way back up and into the
reservoir - try leaning the bike with the brake lever uppermost) if not
you'll need to do a full bleed. In future stick the bike on a stand or
hang it from something when you're working on it. :-)

In article <[email hidden]>,
Fikeus
[email hidden] says...

Quoted message said:

If I had the choice I would go hydraulic, just feel better, the bike
stays more stable specially at breaking at high speed, you don't tend
to get the "Shudder Effect" that you get with cable breaks.

Cable rim brakes shouldn't judder if they're properly set up, although
some brake block compounds seem to cause problems no matter how clean
the rims are.

In article <[email hidden]>, Paul Boyd
usenet.is.worse@plusnet says...

Quoted message said:

Tony Raven said the following on 23/10/2007 08:29:

Quoted message said:

We have them on our tandems and interestingly while nowhere near as bad
as cable stretch there is a definite "hose bulge" equivalent that makes
the rear brake lever much softer than the front.

You want some bling braided hose for that :-)

I remember that from my motorcycling days - Goodridge braided hoses and
anodised alloy fittings were quite the thing to have, apparently. I
remember one local lad who'd fitted ape-hangers to his bike and replaced
the brake hose with a length of clear plastic tubing (the stuff you get
from homebrew shops) and jubilee clips. :-)

In news:[email hidden],
Duncan Smith <[email hidden]> tweaked the Babbage-Engine to tell
us:

Quoted message said:

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.

Quoted message said:

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.

--
Dave Larrington
<http://www.legslarry.beerdrinkers.co.uk>
Never trust a man with more than one moustache.