Hydraulic rim brakes?

[mercalia]

Hydraulic rim brakes?

vsf fahrradmanufaktur T-900

what do people here make of that?

and this German maker?

interesting large frame bike with Rohloff other than that curiosity?


http://www.ebay.co.uk/itm/ROHLOFF-MANUFAKTUR-T-900-BIKE-63CM-FRAME-28-WHEELS-SUPERB-COND-/122432369536?hash=item1c8189b380:g:VG0AAOSwpP9Y5Ldy

[PDQ Mobile]

I have had them on two bikes for over a decade.
Maintenance consists of brushing them clean with a toothbrush twice a year! Otherise no issues.
Pad changing is simplicity itself.
Powerful and easy modulation.
One set has red lever button adjustable on the fly.
Using koolstops, rims stay polished and wear is minimal.
I think they are great.
They are not the most visually pleasing things though.

[Gattonero]

Magura HS brakes are quite reliable, can confirm what said above.
Won't advise them on frames with thin seatstays, they will give them a visible stretch when pulling the brake lever hard, as the hydraulics are powerful.

[psmiffy]

I have used them now for nearly twenty years on my touring bikes - brilliant - very positive - superb modulation - only maintenance I do is to change the blocks every now and then - brake boosters do help with the flex thing

[hamster]

My experience is exactly the same. Run them for 20 years, totally reliable, the only thing I ever do is snap in new pads.
I trusted them to stop a laden tandem on Devon lanes in torrential rain: they did - with zero drama.

[mercalia]

well it seems every one but me knows about them. Then why dont we see them on your Dawes Galaxys or Surlys?

[Halla]

The much maligned Dawes offered them as an optional extra on the Galaxy & Super Galaxy in 1993.

I wonder how many customers opted for them!

[Brucey]

these brakes are indeed powerful and fairly reliable. But....

1) Magura seem to have given up supplying levers for dropped handlebars.

2) the QR arrangements seem a bit hit and miss

3) when problems do occur with the hydraulics it isn't usually an easy roadside fix

4) there is no equivalent of 'an inspection that might reveal a fraying brake cable'; the system can fail to a leak at any time with no real warning

5) occasionally the slave cylinders decide not to move an equal amount, which can drive you berserk with brake rubbing.

6) the running clearance to the rim will vary with the exact brake and setup but it can be small; about the same as some V brakes, i.e. less than with most traditional cantis

7) there isn't much choice in brake pad compounds

8 ) using brake boosters is almost mandatory in many cases

9) the kind of knocks, tugs and scuffs that might cosmetically damage or slightly kink a brake cable can easily cause more severe damage to a Magura hydraulic hose

10) spare parts are 'not available in every LBS'; they usually need to be ordered in specially.

11) you will need a bleed kit, fluid, spare seals and other bits and pieces like a hose clamp etc if you want to work on these brakes, or know an LBS that can do the work

12) they still have the majority of shortcomings that are shared with all other rim brakes.

If there is a compelling reason to use these brakes eg they make an excellent rear tandem brake (vs a cable operated one,) because the hose length doesn't affect brake power, they can be a good choice. However it seems to me that most of the folk who have them on their otherwise ordinary bikes either appear to have wanted them just to be different, or they came on a bike that they bought because 'they thought it was the best' or something.

cheers

[markjohnobrien]

well it seems every one but me knows about them. Then why dont we see them on your Dawes Galaxys or Surlys?

Because they were never specced on production models of these bikes and drop bar model - Magura HS66 - are rare and been out of production since the early 2000s.

The last production run of Raleigh Randonneurs Reynolds 708 from 1999/2000 had these as stock items and most owners praise them for great stopping ability.

Magura continued to make hydraulic rim brakes but no longer for drop bar levers.

[Keezx]

Hydraulic rim brakes?

vsf fahrradmanufaktur T-900

what do people here make of that?

Worst of both worlds.

[peetee]

I have used a set of Magura HS-33 on my MTB for over 10 years now and they are excellent stoppers with good modulation. I have always found them a bit heavy in operation but that's only an issue if you are spending a lot of time on the brakes.

[Gattonero]

Let me be the Devil's advocate

these brakes are indeed powerful and fairly reliable. But....

1) Magura seem to have given up supplying levers for dropped handlebars.

Yes, silly choice in those days where people is using more different setups.

2) the QR arrangements seem a bit hit and miss

True, although this is often not a problem.
Also, they're not brakes for "racing" in today's day, so the user is usually not afraid of spending 1 (one) more minute with a common 5mm allen key? Or just deflate the tyre.

3) when problems do occur with the hydraulics it isn't usually an easy roadside fix

4) there is no equivalent of 'an inspection that might reveal a fraying brake cable'; the system can fail to a leak at any time with no real warning

Depends what the problem is. They are quite reliable and rotten luck can happen with everything

5) occasionally the slave cylinders decide not to move an equal amount, which can drive you berserk with brake rubbing.

OTOH, there is usually ample clearance with the pads/rim, plus the good amount of lateral/orbital adjustment does make up for uneven piston travel

6) the running clearance to the rim will vary with the exact brake and setup but it can be small; about the same as some V brakes, i.e. less than with most traditional cantis

I would add that it depends on the frame/forks as far as distance in the brake pivots. some frames are poorly made with silly narrow brake studs
Not a problem of the brake itself

7) there isn't much choice in brake pad compounds

True

8 ) using brake boosters is almost mandatory in many cases

True, but IIRC they come with the brake?

9) the kind of knocks, tugs and scuffs that might cosmetically damage or slightly kink a brake cable can easily cause more severe damage to a Magura hydraulic hose

OTOH, any "knock" that could damage the hose would certainly give some big damage to the frame or handlebars. The hose needs some tough electrician's scissors to cut it and is resilient to impact.

10) spare parts are 'not available in every LBS'; they usually need to be ordered in specially.

True, but see point 3&4

11) you will need a bleed kit, fluid, spare seals and other bits and pieces like a hose clamp etc if you want to work on these brakes, or know an LBS that can do the work

To replace the seals is not a common thing, it needs real neglicence (and bad planning if is a long trip) to damage them.
A Bleeding kit can be made simply with two suitable pieces of hose and an M5 bolt drilled trough. the hose can be cut with tough scissors or common pliers with no need for specific cutters as wire-brake housing.

12) they still have the majority of shortcomings that are shared with all other rim brakes.

Well, no rim brakes anymore then?

If there is a compelling reason to use these brakes eg they make an excellent rear tandem brake (vs a cable operated one,) because the hose length doesn't affect brake power, they can be a good choice. However it seems to me that most of the folk who have them on their otherwise ordinary bikes either appear to have wanted them just to be different, or they came on a bike that they bought because 'they thought it was the best' or something.

I don't think that those brakes in today's day are used for "show" or being "different".
It was in the 90's that they were the novelty and being used by John Tomac made them popular. Dowhiller would like them because of the less strain given to the hands (same braking power with less force in pulling the brake lever).
In my wiev, they are still a sensible choice if riding in places where long descents are axpected (and cannot switch to disk brakes), and the rider could benefit from less strain on the hands, like people who had CTS

[PDQ Mobile]

2) the QR arrangements seem a bit hit and miss

True, although this is often not a problem.
Also, they're not brakes for "racing" in today's day, so the user is usually not afraid of spending 1 (one) more minute with a common 5mm allen key? Or just deflate the tyre.

Quick releases on both my sets. I had assumed that was how all were manufactured?

QR works well and wheel removal is fast and simple. There is a spacer washer that one needs to keep an eye on though!
But realignment of pad and rim is easy.

Pad changing is simplicity itself much quicker than standard rim brakes.
Koolstop compound is available. Why use anything else!!

[reohn2]

I think the $64K questions are:-
1)How much better stopping power are they than full sized V's if at all?
2)Is the modulation better than V's?
3)Is there any chance of fluid boil on long descents?
4)Are they easily repaired/maintained at the roadside and at home by the owner?
5)are they better in the wet than V's

I've no experience of any kind of hydro bike brake system so these a honest questions a newbie to hydro rim brakes would/should ask IMHO

[Brucey]

I don't entirely disagree with Gatto's 'devil's advocate' comments (everything has a flip side) but

- boosters/QRs don't come with every brake model IIRC; check before purchase if you think you need them

- the hoses are clearly damaged (weakened) if they are kinked and anything that rubs or chafes on the hoses can soon breach them, or make the wall thin enough that it won't withstand the full brake pressure safely. If you subject a Bowden cable to similar treatment it will usually complain (go draggy) or the damage will be obvious (the covering gets chafed through), whereas with Magura hoses a more careful inspection is required.

- when Magura hose connections are remade, on the plus side this usually doesn't require an olive, but on the minus side you need a hose clamp to withstand the insertion load of the push-fit fitting. IME other ad-hoc methods of holding the hose (such as you might use in a pinch) risk that it is damaged; Magura certainly don't recommend such methods. [They will happily sell you a workshop tool that costs about £80; most folk make do with a simpler version that costs £10 but this needs a bench vice or a big set of mole grips, plus a deal more care, to work it.]

I'd also note that Magura rim brakes have been popular with trials riders; I think that the power makes it easier to lock the wheel completely (for wheelstands, hops etc) and the lack of friction in the hydraulics means that the modulation is likely to be slightly better than with cable operated brakes.

Re rim brakes in general; I think they are more than good enough for many types of cycling. However with the exception of small (but possibly significant) improvements in power and modulation, Maguras don't improve upon other rim brakes and leave the issues that drive some folk to disc or drum brakes unaddressed.

Re possible fluid boil; IIRC Magura's own fluid (which is biodegradable) has a very low boiling point vs other hydraulic fluids. Clearly they are bullish on this point. From a thermal perspective I think that Magura rim brakes are less of a worry than disc brakes. [TBH I am surprised that they get away with that same fluid in disc brakes; on long descents very many disc calipers routinely get hot enough to boil that fluid (if the information I have seen is correct)....]

cheers