New disc brakes...

CharlieJohnson

Hi all, I'm looking to replace the disc brakes on my Dawes Super Galaxy (2014). It came with Shimano BR-R517 mechanical disc brakes with 160mm rotors, which are pretty terrible. They require regular adjustment as the lever travel steadily increases over about two weeks until the levers are touching the bar tape. They also do not have barrel adjusters (!!) which means I have to adjust by tightening the cable and changing the position of the pads. Which is a bit of a hassle at such regular intervals.
I've never had disc brakes before so I'm not too sure what the best course of action is. Any suggestions as to why they may be behaving like this? I was under the impression that disc brakes required less adjustment and maintenance than regular callipers.
Would it be possible to replace the callipers without getting new levers? Any suggestions for good callipers? Should I go for hydraulic this time or is that not possible with the levers I have (Shimano ST-4603 STI)?

Thanks for any advice!

ugo.santalucia

There seems to be consensus that the dual piston TRP Spyre are the best out there.

I run Hayes CX Expert (formerly CX 5) and they are very good, but like all mechanical calipers they need to be perfectly aligned and you do need to adjust periodically the pad-disc distance to compensate for wear. Avid BB7 road are also very good

marcusjb

I have had BB7s on one tandem and now have Spyres on another tandem.

Nothing wrong with BB7s - very competent stoppers.

Spyres seem to be (we've only done a few hundred km on them so far) a little bit better as a brake and much easier to setup. Impressed with them so far.

tehtehteh

it's normal to have to adjust the brakes as the pads wear, I take it you do a lot of miles on it if the lever travel is changing so much over 2 weeks?

though the lack of barrel adjusters sounds annoying you should still have a pad adjust on the caliper

you can't get a FULL hydraulic system and keep your mechanical levers, but TRP do a brake that has the reservoir on the caliper so that might be an option for you

personally though I think your brakes should work just fine as they are if they're set up right, changing the caliper would seem like a bit much..... have you thought about adding an inline barrel adjuster instead?

CharlieJohnson

Thanks for the responses. I'm doing about 60 miles a week at most - not a huge amount. Could it be that the cables are cheap and are stretching? Perhaps worth replacing these? I would be really surprised if the pads were wearing at such a rate - I'll get some new pads and see if it makes a difference.
Adding barrel adjusters sounds like a good plan, I'll look into this. Would these do the job for brakes? http://www.wiggle.co.uk/bbb-bcb-93-gear ... adjusters/

rafletcher

TRP Hy/Rd would be my choice. Mechanical actuation of a hydraulic brake - the reservoir is in the calliper. No adjustment required as (like all hydraulic units) the pads are self centreing. Excellent stoppers too.

tehtehteh

CharlieJohnson wrote:

Thanks for the responses. I'm doing about 60 miles a week at most - not a huge amount. Could it be that the cables are cheap and are stretching? Perhaps worth replacing these? I would be really surprised if the pads were wearing at such a rate - I'll get some new pads and see if it makes a difference.
Adding barrel adjusters sounds like a good plan, I'll look into this. Would these do the job for brakes? http://www.wiggle.co.uk/bbb-bcb-93-gear ... adjusters/

hmm yeah 60 miles a week isn't huge, and is similar to what I do and mine don't seem to wear that fast, though I do have a barrel adjuster on my caliper and I often give it a tweak without thinking

it could be you have a different compound pad which wears faster, maybe the conditions you cycle in are worse which will wear the pads faster, maybe the cable is stretching a bit, or a combination of all three, but it's nothing serious or unusual either way

in my experience all cables stretch a little bit early on so need adjusting after a little while, but I wouldn't get a new one just because of that

about the barrel adjuster - make sure you get one for brake cables as they're larger than gear cables

arlowood

CharlieJohnson wrote:

Would these do the job for brakes? http://www.wiggle.co.uk/bbb-bcb-93-gear ... adjusters/

The ones you've linked to are gear cable adjusters. Also with that type you need the appropriate threaded housing either at the lever end or the disc caliper unit for them to work effectively. Might be better to opt for an in-line barrel adjusted like this which is brake cable specific

http://www.rosebikes.co.uk/article/shim ... tAodpEYApA

ElectronShepherd

Something's not right there. Simply adding an inline cable adjuster isn't going to help - all that will do is mask the symptoms and save getting the spanners out once a week - it won't solve the underlying problem.

Cable disks that are working properly do not require adjusting every 60 miles. Cable stretch is a possibility, but unlikely since brake cables tend to be quite thick. If you're pulling on the brakes hard enough to stretch a steel cable that much in 60 miles of riding, you'd have been over the handlebars several times by now.

My guess would be that the clamp bolt on the cable at the caliper is not tight enough, and the cable is simply slipping through the clamp with each brake application. It's easy to tell; get the brakes working and then put a little blob of Tippex on the cable (borrow some of SWMBO's nail polish if you don't have any Tippex) to mark the cable position relative to the clamp, and see if it moves.

CharlieJohnson

Thanks ES, that's a good tip. I'm pretty sure it's tight enough as I've adjusted enough times but I'll give it a go. I know that the bike shipped with cheap cables, I had to replace a gear cable after a week as it began to fray so I think Dawes are skimping on the details. Maybe that's the issue...

rowlers

I have these brakes and I have no issue with them, they are powerful and modulate well.
You can adjust the lever travel using the caliper arm adjustment screw. I don't have barrel adjusters.

Monty Dog

Firstly, ditch the adjusters and try a stiffer outer cable like Goodrich. I have 2x bikes with BB7 but would go to Avid Spyres as the dual piston design is superior.

janwal

+1 for thr TRP HY/RD.Have them on my new Trek Domane and so far are excellent.

aberdeenal

rafletcher wrote:

TRP Hy/Rd would be my choice. Mechanical actuation of a hydraulic brake - the reservoir is in the calliper. No adjustment required as (like all hydraulic units) the pads are self centreing. Excellent stoppers too.

I've got a set of these for my Genesis Croix de Fer - hopefully get them fitted this week - the OEM Hayes CX brakes are pretty pants

cycleclinic

Spyres or Hy-RD unless you can afford Shimano hydraulic disc brakes. Having the pleasure or displeasure of setting up many different brands of mechanical calipers, the ones that are a pleasure are the tektro's. the real bonus is they work well too.

ugo.santalucia

AberdeenAl wrote:

I've got a set of these for my Genesis Croix de Fer - hopefully get them fitted this week - the OEM Hayes CX brakes are pretty pants

No, they're not, yours must be badly fitted

jomoj

I have the BR 517 brakes on my cx bike and have found them to reliable stoppers and easy to maintain. It's annoying that you have to use 2 different allen keys to adjust pad and cable but its a 30 second job.

As others have said, cabling is important. I fitted Jagwire compressionless housing front and rear and feel is really smooth and positive, it certainly doesnt feel spongy. Also fitted a pair of these:

http://www.sjscycles.co.uk/jagwire-mini ... prod24781/

for easy adjustment on the fly but the brake does have a little adjuster bolt on the outside pad that accomplishes the same thing by moving the pad closer to the disc, you shouldn't need to keep adjusting the cable at the the clamp.

meanredspider

thecycleclinic wrote:

Spyres or Hy-RD unless you can afford Shimano hydraulic disc brakes. Having the pleasure or displeasure of setting up many different brands of mechanical calipers, the ones that are a pleasure are the tektro's. the real bonus is they work well too.

Just make sure the HyRds aren't the faulty first gen.

cycleclinic

You can't buy the first gen brakes of upgrade. I buy of distributor not online shops. Besides no one should be selling brakes that were recalled.

meanredspider

thecycleclinic wrote:

You can't buy the first gen brakes of upgrade. I buy of distributor not online shops. Besides no one should be selling brakes that were recalled.

They weren't recalled as far as I know (in fact when I suggested to them that they should be recalled, they ignored my emails (having been very responsive before)). I bought mine at my LBS. I'm suggesting that anybody buying from some of the less "official" sources of HyRds should be careful..

aberdeenal

ugo.santalucia wrote:

AberdeenAl wrote:

I've got a set of these for my Genesis Croix de Fer - hopefully get them fitted this week - the OEM Hayes CX brakes are pretty pants

No, they're not, yours must be badly fitted

They weren't badly fitted - I just don't think they were as good as the brakes fitted on previous CdF models - it's like comparing chalk & cheese against the TRP HyRd's

964cup

Another vote for TRP HY/RD here - with Nukeproof Enduro pads.