Tektro Mechanical Disc Brake Advice

[lejogger]

Afternoon all,

The missus has purchased a Boardman ADV 8.6W which came equipped with Tektro MD-C511 flat mount disc brakes.

The calipers seem okay - fairly simple to adjust, but we're really struggling with stopping power. I'm not a mechanical disc brake novice, for example I have BB7s on the winter bike, and set those up without issue. However these seem to really be taking their time to bed in.

As soon as I'd built the bike I spent a decent amount of time tearing up and down the road building up some speed and hauling on the anchors. We've also done around 50 miles on the road with them so far, but improvement is minimal. Bedding in was not an after-thought. I was always aware that this needed to be done.

It's her first bike for years so am trying to build her confidence, but needless to say this isn't helping matters - especially if a swift stop is required.

What I'd like to know is:

a) Do we just have to keep working on bedding them in, and be assured that they will achieve a reasonable level of grabbiness in the near future?

b) Should I be looking to upgrade the pads from the OEM for significant improvements? If so, what do you recommend? Is there a fancy brake pad website that might be useful?

c) Should I throw in my hand and look to replace the calipers for something of better quality?

Thanks in advance.

 

[si_c]

I'm not a fan of single sided calipers personally, but they can be set up to work adequately. Might be worth winding the cable tension up a little bit so they engage faster. Also make sure the inner pad is very close to the rotor so it doesn't need too much movement to press up against it - use the allen bolt on the inside to wind it in, I'd do so until the rotor scrapes the pad and then back it off a bit.

Also worth checking is if the brake cables are compressionless or regular brake outers - if the latter then that will affect how the brake engages as well, so hopefully it should be compressionless. If not then changing these will help.

 

[Sterlo]

I'm assuming they are similar to hydraulic in their operation. If they don't seem to stop quickly, the pads may be contaminated. If you haven't got some already, but some brake cleaner, remove the pads, sand them lightly with some fine sandpaper then spray some of the cleaner on, give them a wipe, then spray some cleaner on the discs themselves and wipe it off, then put the pads back in. It sounds worse than it is, takes about 10 minutes to do front and back.. If it's a fairly new bike, there could be a bit of oil or grease on them which will take a long time to wear off.

 

[lejogger]

I'm not a fan of single sided calipers personally, but they can be set up to work adequately. Might be worth winding the cable tension up a little bit so they engage faster. Also make sure the inner pad is very close to the rotor so it doesn't need too much movement to press up against it - use the allen bolt on the inside to wind it in, I'd do so until the rotor scrapes the pad and then back it off a bit.

Also worth checking is if the brake cables are compressionless or regular brake outers - if the latter then that will affect how the brake engages as well, so hopefully it should be compressionless. If not then changing these will help.

Hi Si,

Thanks for your reply - agree regarding the single sided calipers - it's why I swapped out the BB5s for BB7s on my winter bike - but I was still hoping these wouldn't be so bad that I wouldn't be able to get them to perform better than they are doing.

I've dialled in the pads/adjusted the cable as close as I can get without them rubbing, also adjusted the levers so that they're more suited for her pathetic girly hands. I don't think it's necessarily that the pads and discs are too far apart, it's more that when the pads and disc engage, they're just not grabbing as much as I would expect.

 

[si_c]

Screw it then I'd throw some Spyres on and be done with it. At the very least swap the front over - I've got a used one going spare if you want it.

 

[lejogger]

I'm assuming they are similar to hydraulic in their operation. If they don't seem to stop quickly, the pads may be contaminated. If you haven't got some already, but some brake cleaner, remove the pads, sand them lightly with some fine sandpaper then spray some of the cleaner on, give them a wipe, then spray some cleaner on the discs themselves and wipe it off, then put the pads back in. It sounds worse than it is, takes about 10 minutes to do front and back.. If it's a fairly new bike, there could be a bit of oil or grease on them which will take a long time to wear off.

Thanks Sterlo,

Yes it's a brand new bike so it could be oil/grease.
Agree it's definitely worth cleaning the discs and pads before leaping to anything more drastic.

 

[lejogger]

Screw it then I'd throw some Spyres on and be done with it. At the very least swap the front over - I've got a used one going spare if you want it.

Thanks Si,
I'll bear that in mind if a clean doesn't sort it.

 

[si_c]

Thanks Si,
I'll bear that in mind if a clean doesn't sort it.

No worries, it's had about 12k miles on it but still works perfectly and has got a relatively new set of pads on it. Only have it lying around as I moved to full hydraulics.

 

[Cycleops]

I’ve got a set of what must be the same brakes. They do stop okay but not the best. They’ve now developed a annoying squeak and the pads are quite new. Upgrading may be the best way to some decent stoppers.

 

[Sterlo]

Another quick thought as well, depends on the pad material. If they are sintered pads, they are a lot harder to last longer, they also IMO, don't stop as well and tend to squeal more. If you decide to stick with the brakes, if they are sintered, change them to resin/organic, they still last a good while but make less noise and I think stop better.

 

[Drago]

Have you adjusted the static pad so it is as close to the disc as possible?

 

[lejogger]

Another quick thought as well, depends on the pad material. If they are sintered pads, they are a lot harder to last longer, they also IMO, don't stop as well and tend to squeal more. If you decide to stick with the brakes, if they are sintered, change them to resin/organic, they still last a good while but make less noise and I think stop better.

Yes they have come with the A10.11 metal ceramic compound.

Tektro alternatives appear to be either:

E10.11 organic compound or
P20.11 high performance metal ceramic compound

Will see if I can find any reviews for these anywhere.

 

[lejogger]

Have you adjusted the static pad so it is as close to the disc as possible?

Yeah, although the rotors don't appear to be particularly true so are tracking through the gap at an angle at times. Which obviously makes getting close to the pads tricky without there being rubbing.

I guess it's not even worth spending ages truing the discs if the single caliper braking process involves bending the rotor onto a static pad.

 

[Drago]

I guess it's not even worth spending ages truing the discs if the single caliper braking process involves bending the rotor onto a static pad.

That's pretty much it on race cars and motorbikes it would be a floating disc, but bicycle discs are thin enough to flex into position. For all its crudity, they should work fairly well.

 

[I like Skol]

I wouldn't waste much time trying to clean pads, once contaminated it is game over. 1st thing would be get back to the shop that supplied the bike (Halfords?) and get them to sort it. Could be that someone got a bit overenthusiastic with the spray lube and killed the pads during the build.
A new set of pads and good clean of the rotors before thinking about swapping out the brakes altogether.