Roadies with disc brakes

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Re: Roadies with disc brakes

Postby biker jk » Thu Jul 03, 2014 3:10 pm

barefoot wrote:
Duck! wrote:
CKinnard wrote:... wondering how finicky and expensive they are to maintain.

They're not. Cable discs need periodic manual adjustment to compensate for pad wear, either by an allen key or integrated dial depending on model to wind in the inboard stationary pad in, and the barrel adjuster to tweak the "active" pad.


Kind of like how you need to adjust rim brakes slightly as they wear.

Just not as often. And easier.

You might need to tweak them a few times when new, as they bed in (and/or new cables stretch and/or new cable outers compress), then you really don't need to touch them... like... for ever.

And there's no risk of ham-fistedly misaligning a pad and putting it into the tyre sidewall either. Not that anyone has ever done that with rim brakes :oops:

I wouldn't bother with hydraulics. They're newer to market, they're still having teething problems, they're expensive, and I'm not convinced of the benefits. I've been a big fan of cable discs for ages, and I'd still be running them on my MTB except that I got a new bike, and all new MTBs come with hydros... which aren't all that much better (although they're Avid hydros, which are notorious for being rubbish, but that's another matter).

tim


Having owned a MTB with Avid BB7 disc brakes they were a pain to adjust and get right plus regular squealing. Rim brakes a far easier to adjust. There is no comparison.
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by BNA » Thu Jul 03, 2014 10:43 pm

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Re: Roadies with disc brakes

Postby Nobody » Thu Jul 03, 2014 10:43 pm

Wakatuki wrote:The front seems to grip but not as strong as I would like. Will see how I go on Saturday.
If it doesn't go that well, a bigger disc should help.
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Re: Roadies with disc brakes

Postby ldrcycles » Tue Jul 08, 2014 10:11 pm

Just a quick question, i have a fork with disc mounts, and a disc hub, is there a specific kind of rim i should be looking at? I vaguely remember reading somewhere that eyeletted rims were necessary with disc brakes, or at least highly recommended?
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Re: Roadies with disc brakes

Postby Duck! » Tue Jul 08, 2014 10:24 pm

First I've heard of that. I've seen heaps of non-eyeletted disc brake-specific rims (and own a pair myself).

You can use any rims, but disc-specific ones are a bit lighter 'cos they don't need the thickened sidewalls for the brake tracks. The sidewalls can also be shaped differently to improve rim strength with the thinner walls (and potentially smooth out the tyre/rim interface for aero gains similar to tubulars).
I had a thought, but it got run over as it crossed my mind.
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Re: Roadies with disc brakes

Postby Wakatuki » Wed Jul 09, 2014 10:20 am

Just an update to my earlier posts. Although I have not been back to the hill on the bike since, I have been riding it to work and out and about with the GLW. I am much happier with it. I have had to trim the front brake in enough to make it also go ting ting on occasion, it just adds to the work out! I am sure it will settle into its position soon enough.
I can confirm the roll into Palmwoods from Woombye was uneventful and the brakes felt fine at the bottom before the left hand pinch.
It will be next Tuesday night 15/7/14 before I see the hill again. (unless Pam wants to climb on Sunday.)
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Re: Roadies with disc brakes

Postby Dragster1 » Wed Jul 09, 2014 11:35 am

Wakatuki wrote:Just an update to my earlier posts. Although I have not been back to the hill on the bike since, I have been riding it to work and out and about with the GLW. I am much happier with it. I have had to trim the front brake in enough to make it also go ting ting on occasion, it just adds to the work out! I am sure it will settle into its position soon enough.
I can confirm the roll into Palmwoods from Woombye was uneventful and the brakes felt fine at the bottom before the left hand pinch.
It will be next Tuesday night 15/7/14 before I see the hill again. (unless Pam wants to climb on Sunday.)

I would consider metallic brake pads after seeing the end result of those in the picture. After years of "ting ting " I have done away with fixed pad calliper brakes as soon as you heat the disc up on a large down hill run the heat buckles the disc rotor and a lot of the times when they cool down the rubbing goes away but its just annoying. The noise seems to echo more in front carbon forks and also the flexing around corners can make the brakes just rub.
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Re: Roadies with disc brakes

Postby Bentnose » Wed Jul 09, 2014 1:02 pm

I replaced the cable discs on my MTB (BB7's) with hydraulic SLX after a couple of wet races were I spent the whole races constantly stopping to adjust brake pads, most of the time braking power was reduced as the brake pads wore. New cables were required after each race and a complete strip down and rebuild of the calipers. They were fine when we had a drought, I'll never go back to cable discs on the MTB and the newer Shimano brakes are actually easy to set up and work on unlike the older Hayes ones I had before I got the cable discs. With the disc brakes on my commuter I seem to be adjusting the pads quite often, I have the Shimano CX70 brakes, almost every ride seems to be in the rain lately, I don't mind the adjusting in this case as it is quite easy and not too often.
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Re: Roadies with disc brakes

Postby m@ » Wed Jul 09, 2014 1:27 pm

What're people's thoughts on the new TRP Hy-RD hybrid cable/hydro brakes? They run a brake cable to the brake body, where it connects to the hydraulic system.

Can't quite decide whether they're the best of both worlds, or a cheap compromise... at $150 an end I might end up with a set to test the theory. For C/X, I suspect their previous system of a cable/hydro converter mounted under the stem might actually be better as it keeps the cable section away from dirt and mud.

Pros:
  • Maybe better modulation than cable
  • Maybe better power than cable
  • Auto-centering pads
  • Very low volume of hydro fluid - should rarely need bleeding and avoid 'spongeyness' due to air in lines (esp rear).
  • Cheap, and works with cable-based brifters

Cons:
  • Cables are heavier than hydro hoses
  • Cables still subject to dirt/water contamination and friction
  • Low, but not non-existent, risk of hydraulic leaks/air bubbles
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Re: Roadies with disc brakes

Postby mitchy_ » Wed Jul 09, 2014 2:13 pm

from everything i've read, they sit between cable and hydro.
they have many of the pro's you listed such as self adjusting, double sided pads.. however they still have that "cable" feel unlike the rock solid hydro feel.

at 200 grams each, they aren't as light as a spyre either (~150 grams)

i was going to try sram hydro... however i'm giving the TRP Spyre's a crack. if they aren't up to par i'll put them on my CX bike and then try proper hydro.
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Re: Roadies with disc brakes

Postby thomashouseman » Wed Jul 09, 2014 2:25 pm

biker jk wrote:Having owned a MTB with Avid BB7 disc brakes they were a pain to adjust and get right plus regular squealing. Rim brakes a far easier to adjust. There is no comparison.

Bentnose wrote:I replaced the cable discs on my MTB (BB7's) with hydraulic SLX after a couple of wet races were I spent the whole races constantly stopping to adjust brake pads, most of the time braking power was reduced as the brake pads wore. New cables were required after each race and a complete strip down and rebuild of the calipers..


Wow, you MTB'rs must hammer them... I have a commuter roadie with cable road BB7's and I only give em a single click on the adjuster every few weeks and I'm good to go. Have replaced the pads once in the past year and do several hundred km's a month.

I use the bike rain, hail or shine (except when sick).

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Re: Roadies with disc brakes

Postby jacks1071 » Wed Jul 09, 2014 2:30 pm

Duck! wrote:
CKinnard wrote:I am looking at buying a CX or enduro road bike. I've never had disc brakes before, and am wondering how finicky and expensive they are to maintain.

They're not. Cable discs need periodic manual adjustment to compensate for pad wear, either by an allen key or integrated dial depending on model to wind in the inboard stationary pad in, and the barrel adjuster to tweak the "active" pad. Hydraulics are even easier - they do it themselves. Pads cost a little more than rim brake pads, but last considerably longer (=> cheaper in the greater scheme of things).


I'm going to disagree with you on pad life.

A set of rim pads will last significantly longer than disc pads on a road bike. Probably something like 4 - 10x longer.
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Re: Roadies with disc brakes

Postby Wakatuki » Wed Jul 09, 2014 2:33 pm

I have read and followed the article Forum review well written and someones real cash not a magazine review. Oh and they have them fitted to a Kona :roll:
I think they are an improvement BUT if I could go full hydro I would be there in a shot.
Buying the HY/RD I would just be another $300+ further away from doing so when they do become available. (now searching for metallic pads! :D )
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Re: Roadies with disc brakes

Postby m@ » Wed Jul 09, 2014 3:13 pm

mitchy_ wrote:from everything i've read, they sit between cable and hydro.
they have many of the pro's you listed such as self adjusting, double sided pads.. however they still have that "cable" feel unlike the rock solid hydro feel.

at 200 grams each, they aren't as light as a spyre either (~150 grams)

i was going to try sram hydro... however i'm giving the TRP Spyre's a crack. if they aren't up to par i'll put them on my CX bike and then try proper hydro.


Cool, might wait for your feedback before taking the plunge... I would love to throw on SRAM S700 brifters and Red brakes, but the cost is prohibitive ATM.
Wakatuki wrote:I have read and followed the article Forum review well written and someones real cash not a magazine review. Oh and they have them fitted to a Kona :roll:
I think they are an improvement BUT if I could go full hydro I would be there in a shot.
Buying the HY/RD I would just be another $300+ further away from doing so when they do become available. (now searching for metallic pads! :D )

Yeah, that's my worry... I do have a set of cable BB7s (on my Kona commuter - Honky Inc - as is @thomashouseman's IIRC?) which I could borrow in the meantime (will be cannibailising the 105 brifters and FD from that bike anyway).

Thanks for the link - will add to my read-at-home-later list :)

Similar experience to others with the BB7s - still on the original (used) metallic pads that were on the bike when I bought it 18 months ago; it's ridden mostly in the rain (though not all that much of late). Once I got the brake housings parallel to the rotors I've found adjusting the pads trivially simple, but do tend to get some light rubbing when it's wet, especially hammering around corners and out of the saddle (the Melburn Roobaix was pretty good for all of the above!). Being Avid, they do squeal though!
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Re: Roadies with disc brakes

Postby mitchy_ » Wed Jul 09, 2014 3:18 pm

m@ wrote:Cool, might wait for your feedback before taking the plunge... I would love to throw on SRAM S700 brifters and Red brakes, but the cost is prohibitive ATM.


will let you know how they go when they finally arrive!

the CX has Hayes CX Experts on it, and i had BB7 S Road's on the roadie.. so i should have a decent comparison of the 3.
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Re: Roadies with disc brakes

Postby outnabike » Wed Jul 09, 2014 5:28 pm

It won't affect me, but what is the solution to changing a wheel quickly in the new disc brake line up. I imagine a new wheel ready with brakes attached with a ball joint Hydraulic bayonet fitting or a split coupling if cable operated.
I am thinking it would be Hydraulic wouldn't it? Or would boiling fluid and air in the line dictate brakes that are cable operated?
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Re: Roadies with disc brakes

Postby mitchy_ » Wed Jul 09, 2014 5:34 pm

outnabike wrote:It won't affect me, but what is the solution to changing a wheel quickly in the new disc brake line up. I imagine a new wheel ready with brakes attached with a ball joint Hydraulic bayonet fitting or a split coupling if cable operated.
I am thinking it would be Hydraulic wouldn't it? Or would boiling fluid and air in the line dictate brakes that are cable operated?


what does cables have to do with changing the wheel? :?

it's the exact same as changing the wheel on a rim brake bike. undo axle, drop out wheel and slide new wheel in place (make sure the rotor slots into the caliper, a lot of brakes have tapered pads, etc to guide the wheel in) do up axle and ride away.
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Re: Roadies with disc brakes

Postby Dragster1 » Wed Jul 09, 2014 6:04 pm

Just for the record I can change my disk front wheel faster than my rim braked bike, the rear would be about 3 to 5 secs slower a little care is needed to feed it around the chain and slot it in the rotor in the gap. The heat of the disk doesn't matter because I don't need to touch that part.
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Re: Roadies with disc brakes

Postby Mulger bill » Wed Jul 09, 2014 7:42 pm

outnabike wrote:It won't affect me, but what is the solution to changing a wheel quickly in the new disc brake line up. I imagine a new wheel ready with brakes attached with a ball joint Hydraulic bayonet fitting or a split coupling if cable operated.
I am thinking it would be Hydraulic wouldn't it? Or would boiling fluid and air in the line dictate brakes that are cable operated?

Removal is easier and quicker because you don't have to release the brake. The callipers are attached (and stay that way) to the frame, only the rotor comes away with the wheel.
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Re: Roadies with disc brakes

Postby outnabike » Wed Jul 09, 2014 9:25 pm

Ok, with the questions I had seen on removing and replacing pads, I thought it would be a bit of a slow down..stupid question. Believe it or not I have never removed a wheel with a disc brake... Yet. :)
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Re: Roadies with disc brakes

Postby MattyK » Thu Jul 10, 2014 10:10 am

m@ wrote:What're people's thoughts on the new TRP Hy-RD hybrid cable/hydro brakes? They run a brake cable to the brake body, where it connects to the hydraulic system.

Can't quite decide whether they're the best of both worlds, or a cheap compromise... at $150 an end I might end up with a set to test the theory. For C/X, I suspect their previous system of a cable/hydro converter mounted under the stem might actually be better as it keeps the cable section away from dirt and mud.

Pros:
  • Maybe better modulation than cable
  • Maybe better power than cable
  • Auto-centering pads
  • Very low volume of hydro fluid - should rarely need bleeding and avoid 'spongeyness' due to air in lines (esp rear).
  • Cheap, and works with cable-based brifters

Cons:
  • Cables are heavier than hydro hoses
  • Cables still subject to dirt/water contamination and friction
  • Low, but not non-existent, risk of hydraulic leaks/air bubbles


Apparently they have a fair bit of lever travel before they start to move the pads. So you end up pulling close to the bars.

For CX I would get Gevenalle CX Hydraulic levers (based on a TRP Hylex full-hydro lever):
http://www.gevenalle.com/store/products/shifters/

jacks1071 wrote:I'm going to disagree with you on pad life.

A set of rim pads will last significantly longer than disc pads on a road bike. Probably something like 4 - 10x longer.

But the rims will last infinitely longer. Pads are much cheaper than wheels...
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Re: Roadies with disc brakes

Postby MattyK » Thu Jul 10, 2014 10:11 am

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Re: Roadies with disc brakes

Postby ldrcycles » Thu Jul 10, 2014 3:46 pm

In looking around at various STI compatible discs, i've noticed a common theme with BB7s is noise, what do the BB7 users here think?
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Re: Roadies with disc brakes

Postby Wakatuki » Thu Jul 10, 2014 4:05 pm

ldrcycles wrote:In looking around at various STI compatible discs, i've noticed a common theme with BB7s is noise, what do the BB7 users here think?

It will be equal to or less than the un-oiled chain on your bike!! :P
Hayes CX Expert (CX5) and matching pads and disks, noisy when wet but I think that's common across the board.
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Re: Roadies with disc brakes

Postby silentbutdeadly » Thu Jul 10, 2014 4:45 pm

ldrcycles wrote:In looking around at various STI compatible discs, i've noticed a common theme with BB7s is noise, what do the BB7 users here think?


A common Avid trait when you don't have the discs properly aligned and you haven't gone to the effort to properly bed the disc pads in.

I'm beginning to wonder if cable, cable/hydro and hydro discs on roadies are worth it when you consider that the magnificent Shimano XT brakeset for MTB can be had for as little as $100 per end including levers and calipers but not including the rotors. And yet Shimano does their Ultegra (and XT ) equivalent spec mechanical shift hydro road levers alone for $500 plus...700 if you want calipers and you still have to get rotors.

Even the TRP Hylex system is AU$180 per end plus rotors without the shift capacity though at least this is comparable with a Avid BB7 cable disc with no shift road brake levers

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Re: Roadies with disc brakes

Postby MattyK » Thu Jul 10, 2014 5:15 pm

ldrcycles wrote:In looking around at various STI compatible discs, i've noticed a common theme with BB7s is noise, what do the BB7 users here think?

With the old "roundagon" rotors they used to make a weird "turkey gobble" noise as people called it.
With the G2 rotors it's more of a whirring noise, not unpleasant.
When wet, get earplugs...
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