Author Topic: Let's talk Hydraulic brakes  (Read 2065 times)

Re: Let's talk Hydraulic brakes
« Reply #25 on: January 20, 2020, 11:45:36 am »
Avoid DOT 5.1 systems and anything without provision for fluid expansion.

Interestingly, the only hydro brakes I has problems with were some Giant (IIRC) proprietary ones, with a large (relatively) reservoir at the lever. In hot weather that heated up and caused fluid expansion that locked the brakes on.

Shimano have a tiny sealed reservoir in the lever, and work well.

We are making a New World (Paul Nash, 1918)

Regulator

  • That's Councillor Regulator to you...
Re: Let's talk Hydraulic brakes
« Reply #26 on: January 20, 2020, 11:54:55 am »
I was thinking more about the reduced cabin pressure,

Passenger aircraft holds are normally pressurised.  There's really no reason these days to deflate tyres...


I'll throw a curve ball in... hydraulic rim brakes.  I have Magura's on my vsf Farrhadmanufaktur touring bike and my Kalkhoff electric bike.  Great stopping power - even with a lard arse like me on board.
Quote from: clarion
I completely agree with Reg.

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Re: Let's talk Hydraulic brakes
« Reply #27 on: January 20, 2020, 12:05:19 pm »
Big fan of HDB. So nice to use on the sort of races we do.
35,000 km on my endurance bike and no problems.
Ive had the brakes serviced once by a mate. (Im not capable and would be in trouble if a drama happened mid ride)
The one thing that concerns me is when travelling with a fairly small soft bike bag.  I have to twist the fires which does put strain on and pinch the brake line.
Other than that they have been bomb proof.
often lost.

FifeingEejit

  • Not Small
Re: Let's talk Hydraulic brakes
« Reply #28 on: January 20, 2020, 12:59:59 pm »
I have not yet had a problem stopping with BB7 roads on the recumbent, even on a loaded tour. I can't think where it would have been to my advantage to have been able to lock up more quickly.

The advantage of the Bb7s to me is road side fettlability, just a quick tweak on the adjusters at a control, spare cable and pads in rack pack.

In the case of hydraulics though, I'm not sure I'd bother with carrying repair kit, other than perhaps spare pads. I'd simply accept that I ride cautiously with one brake until I can deal with it properly.

The one major downside of BB7s that I will claim is their use of the Avid Juicy pads and retention spring.
That and being tricky to set up just right are about all I can fault them on in terms of being decent brakes.

Hot Flautus' list however does give a good idea of where Hydraulics really are better.


The M535s needed bled regularly,
I've only bled the newer shimano ones when building or replacing the calipers  I broke the pistons on.
They're probably due a full oil change now I think of it.

Kim

  • Timelord
Re: Let's talk Hydraulic brakes
« Reply #29 on: January 20, 2020, 01:15:14 pm »
I was thinking more about the reduced cabin pressure,

Passenger aircraft holds are normally pressurised.  There's really no reason these days to deflate tyres...

There never was a reason to deflate tyres, they'd be fine in hard vacuum (it's only another 14.5PSI).  Hydraulics might be more fussy...


Quote
I'll throw a curve ball in... hydraulic rim brakes.  I have Magura's on my vsf Farrhadmanufaktur touring bike and my Kalkhoff electric bike.  Great stopping power - even with a lard arse like me on board.

For something that combines the disadvantages of both, these are unexpectedly lovely.  You get the power and modulation (and sometimes self-adjustment, depends on the model) of hydraulic discs, low maintenance and much simpler pad adjustment than V-brakes (more like a disc brake).  But you also get the water-clearance lag and rim wear you expect from rim brakes.  I don't think you can get road levers for them, though.
Careful, Kim. Your sarcasm's showing...

LittleWheelsandBig

  • Whimsy Rider
Wheel meet again, don't know where, don't know when...

ElyDave

  • Royal and Ancient Polar Bear Society member 263583
Re: Let's talk Hydraulic brakes
« Reply #31 on: January 20, 2020, 01:38:13 pm »
I was thinking more about the reduced cabin pressure,

Passenger aircraft holds are normally pressurised.  There's really no reason these days to deflate tyres...

There never was a reason to deflate tyres, they'd be fine in hard vacuum (it's only another 14.5PSI).  Hydraulics might be more fussy...


Quote
I'll throw a curve ball in... hydraulic rim brakes.  I have Magura's on my vsf Farrhadmanufaktur touring bike and my Kalkhoff electric bike.  Great stopping power - even with a lard arse like me on board.

For something that combines the disadvantages of both, these are unexpectedly lovely.  You get the power and modulation (and sometimes self-adjustment, depends on the model) of hydraulic discs, low maintenance and much simpler pad adjustment than V-brakes (more like a disc brake).  But you also get the water-clearance lag and rim wear you expect from rim brakes.  I don't think you can get road levers for them, though.

Yes aircraft holds are pressurised, but only to about 8-10000ft.  There is a manufacturers warning on my insulin pump that it might behave oddly at those pressures, so monitor blodd glucose more regularly.  I'm joining ...
“Procrastination is the thief of time, collar him.” –Charles Dickens

Cudzoziemiec

  • Waking up now, put the kettle on!
Re: Let's talk Hydraulic brakes
« Reply #32 on: January 20, 2020, 01:40:53 pm »
A fellow crashed during the last day of PBP Audax 2016, twisting a brake lever and pulling the hydraulic line out. A crash could fairly easily take out a road hydraulic brake when a cable lever could just be pushed back into place. You pays your money and...
I heard of a similar incident on one of the TINATs. In that case, the rider was able to carry on, though injured, riding carefully with only a rear brake.

But it's just something I was told about, albeit by someone who was riding with the person, I didn't see it myself. And we probably don't hear if crashing happens with cables leads to a smashed lever, for instance, unless we know the rider. And all of these are going to be rare cases.
I do not ride a great big Mercian, gangster tanwalls, fixed cog in the back.

LittleWheelsandBig

  • Whimsy Rider
Re: Let's talk Hydraulic brakes
« Reply #33 on: January 20, 2020, 01:42:52 pm »
I've crashed during races and general rides, pushed the brake lever back straight and continued riding more than once.

I see hydraulic brakes as akin to electronic shifting - great if it works and it probably will continue to work but if it stops working, it is probably a pain in the arse/ expensive to fix.
Wheel meet again, don't know where, don't know when...

simonp

  • Omnomnomnipotent.
Re: Let's talk Hydraulic brakes
« Reply #34 on: January 20, 2020, 02:54:39 pm »
I had a hydraulic brake failure, rear Shimano caliper had a leak, most likely from the transfer port seal (the caliper is made in two halves and there is a port between them with a small rubber seal). This was a warranty replacement, it was likely something like the seal having been pinched during assembly in the factory, or perhaps a casting issue. It was slowly losing fluid and replacing it with air, and this showed up when I inverted the bike to work on something, and the air got into the hose, and suddenly no rear brake.


Wowbagger

  • Dez's butler
    • Musings of a Gentleman Cyclist
Re: Let's talk Hydraulic brakes
« Reply #35 on: January 20, 2020, 03:13:50 pm »
We've got the on the Circe tandem. I have had to bleed the rear brake a few times. It's a bit annoying.
Oh, Bach without any doubt. Bach every time for me.

Re: Let's talk Hydraulic brakes
« Reply #36 on: January 20, 2020, 03:20:45 pm »
What I do find is that I have to drop the wheel out and pump the pistons out to lessen the travel every few weeks.

fuaran

  • rothair gasta
Re: Let's talk Hydraulic brakes
« Reply #37 on: January 21, 2020, 12:37:05 am »
Avoid DOT 5.1 systems and anything without provision for fluid expansion.
Most Hope brakes use DOT 5.1, they work great. Its not really a problem.
Just don't leave the bottle with the lid open, or spill it over your bike, or drink it... 🤢

ElyDave

  • Royal and Ancient Polar Bear Society member 263583
Re: Let's talk Hydraulic brakes
« Reply #38 on: January 21, 2020, 07:01:53 am »
Whereas Shimano hydraulic fluid makes an interesting martini?
“Procrastination is the thief of time, collar him.” –Charles Dickens

Re: Let's talk Hydraulic brakes
« Reply #39 on: January 21, 2020, 07:08:10 am »
Well, it's not hygroscopic and isnt a paint stripper. It also doubles as a lube for mavic hubs.

Re: Let's talk Hydraulic brakes
« Reply #40 on: January 21, 2020, 09:21:27 am »
I've got some Juin Tech F1s waiting to go on my new bike. I don't know if i like them yet, but they seemed like a reasonable compromise on features.

Why not hydraulics? (I think I've said it before, but) partly the roadside fixability. Mostly that i haven't found integrated shifters that i like. When I've felt lack of stopping on a road bike it was mostly at the tyre / road interface rather than the brakes.

Sent from my SM-G930F using Tapatalk


Re: Let's talk Hydraulic brakes
« Reply #41 on: January 21, 2020, 10:29:47 am »
It's not really about stopping power.

I had some Juins. I no longer have Juins.

Re: Let's talk Hydraulic brakes
« Reply #42 on: January 21, 2020, 10:53:53 am »
The useful travel on drop bar levers is so short that self-adjustment is essential* with disc brakes to avoid them bottoming out on the bar, unless you plan to fettle them every 12 minutes. I don’t think the hybrid brakes come close to the feel of proper hydraulics though, if that’s the goal.

(* in my personal experience. I’m sure I’m an idiot who Isn’t Doing It Right)

Re: Let's talk Hydraulic brakes
« Reply #43 on: January 21, 2020, 11:51:10 am »
When I first got hydros the travel really bugged me. I bked and bled thinking that was the issue. Then I realised I just needed to periodically pump out the pistons by operating the brakes with no wheel every few hundred miles.

zigzag

  • unfuckwithable
Re: Let's talk Hydraulic brakes
« Reply #44 on: January 21, 2020, 02:58:48 pm »
there are pros and cons with every system, for me there is no clear winning technology. failures are very rare, it's pure chance whether something happens to you or it may never happen.
let's take my example on tinat 600. i crashed at around 160k, nothing major, only handlebars twisted to the side, right shifter/lever turned inwards 45 degrees and bent derailleur hanger. it took me a few minutes to sort it out and carry on. back then i was wondering if i'd been able to carry on had my bike had hydraulic brakes and electronic gears. maybe, maybe not.
another example. on hydraepic challenge my bike fell into muddy water and the left shifter filled up with mud. shifting became stiff and jammy. in this case electronic shifting would not have been affected at all (imo), so swings and roundabouts. touch wood i haven't had a ride ending mechanical on any of my long rides so far.

i like and use hydraulic brakes on one of the bikes, they work fine and don't require attention. as for "adventure" cycling, i'm not yet convinced they are the most suitable option (for me).

Re: Let's talk Hydraulic brakes
« Reply #45 on: January 22, 2020, 01:55:35 pm »
Avoid DOT 5.1 systems and anything without provision for fluid expansion.

Interestingly, the only hydro brakes I has problems with were some Giant (IIRC) proprietary ones, with a large (relatively) reservoir at the lever. In hot weather that heated up and caused fluid expansion that locked the brakes on.

Shimano have a tiny sealed reservoir in the lever, and work well.

Giant MPH brakes (and some other models) were 'closed system'. If they are not bled properly they behave exactly as you describe. If they are 100% gas free and full of clean fluid, they rarely give the kind of trouble you describe.

Any hydro brake can of course misbehave if it is not bled or has the wrong amount of fluid in it (surprisingly common).

Shimano calipers fail to leaks either at the caliper half seal or in the piston seals. The cause is usually corrosion. I have a box full of failed calipers.

cheers

Re: Let's talk Hydraulic brakes
« Reply #46 on: January 22, 2020, 04:55:57 pm »
Just back from a ride this morning. Sheeting rain, slick oily roads. Sand and grit.
I was on the endurance bike that has hydro brakes and wide tires so continued on.
On the regular road bike I would have gingerly headed straight home.
often lost.

Re: Let's talk Hydraulic brakes
« Reply #47 on: January 22, 2020, 05:38:23 pm »

Shimano calipers fail to leaks either at the caliper half seal or in the piston seals. The cause is usually corrosion. I have a box full of failed calipers.

cheers

Given you are not a mechanic and don’t work in a bike shop. How did you acquire a box full of failed calipers?
If you don’t make time for exercise now, sooner or later you’ll need to make time for ill health.

ElyDave

  • Royal and Ancient Polar Bear Society member 263583
Re: Let's talk Hydraulic brakes
« Reply #48 on: January 22, 2020, 05:48:43 pm »
Just back from a ride this morning. Sheeting rain, slick oily roads. Sand and grit.
I was on the endurance bike that has hydro brakes and wide tires so continued on.
On the regular road bike I would have gingerly headed straight home.

I test rode a bike with 28mm road tyres and BB7s today, not raining heavily, light drizzle and shitty cambridge roads with construction and farming mud all over. I carried on.
“Procrastination is the thief of time, collar him.” –Charles Dickens

Re: Let's talk Hydraulic brakes
« Reply #49 on: January 22, 2020, 06:00:10 pm »

Shimano calipers fail to leaks either at the caliper half seal or in the piston seals. The cause is usually corrosion. I have a box full of failed calipers.

cheers

Given you are not a mechanic and don’t work in a bike shop. How did you acquire a box full of failed calipers?

I offered an LBS to see why these brakes were failing so often.  With my own brakes I would probably take the trouble to maintain them better and to perhaps repair them. However at shop labour rates it just isn't worth it, and even a tiny chance of a repair not being successful is enough to kybosh it entirely; a new caliper is a pretty reliable solution, for a year or so at least. After that if the caliper hasn't been treated with silicone grease and has been used on our lovely salt encrusted roads, chance of failure seem pretty high.

cheers