Help with disc brakes on new bike

[tincaman]

You need to be going downhill to bed them in, at about 15mph drag one of the brakes for 5 seconds to heat it up and then come to a full stop with maximum pull. Repeat 5 times for each

 

[G3CWI]

A mate has recently bought a Trek roadbike with disc brakes. He is underwhelmed with them. They faded when he did a long descent recently. They were also very noisy although that has calmed down now. He is now considering changing them to Shimano Icecools.

 

[sight-pin]

It may be worth a go with a cleaner, something like this could help
https://www.cycledivision.co.uk/muc-off-disc-brake-cleaner-400ml?gclid=CLzEiaL8vMcCFYu4GwoddX8E_Q

 

[Elswick Cotterpin]

Mine were the same; same make too, I think, not brilliant to begin with but working well now. I think it takes a while for them to come into their own, which is a bit unfortunate for something as important as a brake... They do get better, I try to avoid it but it is possible to lock the wheels, back one anyway, haven't tried the front. I like them; also, they look cool.

 

[Kbrook]

Thanks everyone, I have just about given up, today I've cleaned the pads and rotors with sandpaper and brake cleaner. I've adjusted the pads in and out and even when they are just about touching the rotors there is no way I can lock the back wheel up, in fact down a hill it won't even bring me to a stop without the front brake. The front brake isn't powerful enough to lock the wheel either. I know modulation is supposed to be a benefit of discs but surely if you press the levers sharply in it should lock the wheels up.
I'm going to stop messing now and take it out when it rains to see what it's like in the rain, which is why I got the thing in the first place as a wet weather bike.

 

[G3CWI]

It all sounds rather worrying. I hope that you don't have too many big hills nearby. The odd thing is that this is hardy new technology. It should work perfectly every time. You have to be able to rely on brakes.

 

[vickster]

Take it back to the shop and get them to check everything?

 

[Katherine]

It's after reading this thread that I realise how much shorter my stopping distances are now than 5 months ago when I first got the bike. The brakes worked ok but now they're great. I've done 1012 miles!

 

[DEFENDER01]

And yet i have a Carrera Vengeance MTB with cable disc brakes that'll shoot me over the handlebars

Yes dont they just i also have the Carrera Vengeance took a bit of getting use to even in the wet they were just as good.

 

[bikingdad90]

Stupid question. Was the bike new or used and new to you?

I have had a case where braking was rubbish because the pads were worn and also not even. There was a lip where the back would catch first then pull it forward so the whole pad caught best way to describe it was the opposite to toe in.

The best way I have found to set them up is to push the piston in so the pads grip the rotor tight so wheel cannot spin. Then loosen the caliper bolts slightly and back off the pads by a quarter of a turn. Give the wheel a spin then apply the brake. Hold it on while you tighten the caliper bolts. It is now centered with correct toe in.

To adjust the force and travel on the cable simply shorten or lengthen the cable pull at the caliper.

 

[Kbrook]

Thanks all for the replies. Chris Harte it's a new bike and I have tried your suggestion without success but thanks anyway. Emailed the manufacturer to see what they say. It appears from the research I've done that I'm not the only one with this issue but there are plenty of satisfied customers as well. Will update this thread if I solve the issue.

 

[Tom B]

Sounds an awful lot like the issues i had with my Tektro HDC-300 disk when new. I can only really echo what other people have said about bedding them in, they took a month or so of almost daily riding to get better and I have plenty of big stops around my commute. I found the less i faff around with them and just let them get on the better. Even cleaning and degreasing them dulls the performance. You really need to generate some serious heat in them to bed them in. Try running around with the brake rubbing for a few miles.

I eventually replaced the Tektros with Shimano M615 (thanks for recommendations guys) not because of poor performance, but because I wanted something with adjustable reach and again needed to bed them in. Some of the sintered pads are really hard and thus take a lot of bedding in, but last forever IMX.

 

[MichaelW2]

You need to be going downhill to bed them in, at about 15mph drag one of the brakes for 5 seconds to heat it up and then come to a full stop with maximum pull. Repeat 5 times for each

After bedding in, brakes should be smokin' hot; too hot to touch. Some people recommend splashing water over to cool them down.
Use the steepest hill you can find. Brake hard, but not so as you lockup and skid.

It may be that the OP has contaminated pads. I have never been able to remove oil from (resin) pads.

 

[Pale Rider]

As with all things bicycles, spending some money should cure the problem.

The hybrid cable operated hydraulic disc brakes are said to be excellent.

The reservoir is on top of the calliper, so no need to tinker with the brake lever/shifter - assuming you have drop bars.

The callipers should simply bolt on, but fit needs to be checked because clearance at the rear where the seat and chain stays meet is often tight.

http://www.bikeradar.com/gear/categ...hy-rd-cable-hydraulic-road-disc-brakes-47188/

 

[Tom B]

After bedding in, brakes should be smokin' hot; too hot to touch. Some people recommend splashing water over to cool them down.
Use the steepest hill you can find. Brake hard, but not so as you lockup and skid.

It may be that the OP has contaminated pads. I have never been able to remove oil from (resin) pads.

I would add to that brake while keeping pedaling down the steady hill will generate some heat.

Sprinkling water on to hothothot disks worries me about them warping, for the same reason you shouldnt hold the brake on after a long hard decent (same goes for cars) as the pad insulates the part of the disk it is touching and stops it cooling as the same rate, this coupled with the clamping action can lead to the disk warping and the chinkchinkchink /judder judder judder of warped disks.

I have had resin pads and have had some success decontaminating them by using brake cleaners and then cooking them with a couple of trips down the rammy rake at speed with repeat stops until they smoke and fade.