Mechanical disc brakes lacking stopping power

Question

I bought a carbon road bike about 4-5 months ago with Tektro Spyre dual pivot mechanical disc brakes. Love the bike except for the brakes :(

Brakes are not too bad on the flat but when going downhill with my hands on top of the drops, i have to use all my hand strength to stop and even then it doesn't stop straight away.

This is my first bike with disc brakes and I am wishing I didn't buy it. The husband has the 'normal' brakes on his and they are fantastic.

Options offered by a bike shop were - sell the bike and get a new one (love everything except the brakes about this bike and they're sort of important :)), change the brake pads and they would bed them in for me by riding the bike for hours, change the brakes to hydraulic.

Would appreciate any advice about which way to go here. Obviously i am looking at the cheapest option first which is to change the brake pads.....thoughts???

Many thanks Cath

Answer 1

I have TRP spyres and while I find they perform better than BB7's when properly adjusted, they are very sensitive to adjustment. They have a very narrow range between rubbing the disk and too far away for proper braking. You may have to put up with a slight bit of rub to get proper braking performance.

While they are dual actuated[1] like hydraulic disk brakes, they are not self-adjusting. This means that as the pads wear the brakes need to be adjusted to compensate for the wear; it does not take much for these brakes to get out of adjustment.

You will need a 3mm hex wrench to do the adjustment and if you are going to stick with this bike, I recommend that you learn to do it yourself. You need to adjust both brake pads on a regular basis. I've gotten in the habit of checking my brakes before every ride. They don't need adjusting every ride, but it something to watch.

If that seems like more than you want to deal with, your options are to either switch to BB7's or a more expensive road hydraulic setup. BB7's work well and aren't nearly as sensitive being adjusted properly, but since they only have a single actuator they are not as easy to modulate. For a road bike that is much less of an issue than for a bike meant to function well on dirt. BB7's do require regular adjustment, but in my experience not nearly as much as the Spyre's. They also do not require a tool to do the adjustment.

The last thing to check is that your TRP's are the proper model. Mechanical disk brakes often come in both Road and Mountain models that work with different pull ratios. Since these brakes were on the bike to begin with it's unlikely, but it is something to check. Look online at both models and look at the length of arm that moves the brake pads to determine if you have a road or mtb version.

[1]- dual activation means both pads move toward the disk, most other mechanical disk brakes have one fixed pad and one moving pad.

Answer 2

The review I read indicates the Spyre are better than BB7's - being the gold standard for cable discs. If you cannot easily lock up the back wheel, the brakes are not working correctly.

If what you say is true about the advice you have been given you need another bike shop. There are two steps you need to go though - assess if the brakes are in fact performing as they should (I suspect not). This then guides you as to the next step - repair or replace if bad, if performing as expected, upgrade or accept them as they are.

Answer 3

I would suggest the following steps, in this order:

• Firstly and most importantly, verify that the brakes are correctly installed and set-up. Spyre's can be sensitive to pad position and cable setup. The bike shop should do this free of charge, assuming that you bought the bike from them
• Change the brake pads as suggested
• Upgrade the cables and housings to compressionless housing.
• If the above fail, you could change to hydraulic brakes, but it will be expensive

Answer 4

As others have said, first verify installation and adjustment. I would not be happy with the answers given by your bike shop if I were in your situation, and would consider using a different one. They seem to be more focused on getting you to spend money rather than fixing your problem

Look into upgrading brake pads. Either independently research alternative pads or ask for advice at a different shop. If or when you install new pads you can bed them in yourself, rather than paying a repair technician to do it.

If adjustment and upgraded pads does not work for you and you want to upgrade, you may not need to go full hydraulic (which would include replacing the lever/shifter units). Tektro offers the TRP HY/RD hydraulic cable actuated calipers which are an upgrade from the TRP Spyre model.

You may also find that you only need to upgrade the front brake to achieve the stopping power you are looking for.

Answer 5

One thing that I have found has a massive effect on the braking performance of cable brakes (both rim and disc) is the cables and housing. I started riding a long time ago, in 1994 to be exact, and at that time cable brakes were the standard and, as a result, shop mechanics and even regular Joes knew how to properly measure and cut cables and cable housing. In the last quarter century or so, hydraulic brakes have become the norm for high-end bikes and as a result, most regular Joes and even many shop mechanics don't know how to cut cables and housing. So it may be that your brakes have poorly cut cables and or housing, or have housing that is too long, or routed poorly (for example, with sharp bends that induce friction). Sheldon Brown's trusty old website has a great guide to how to cut cables and housing: http://www.sheldonbrown.com/cables.html Other causes of poor braking power may be, as others have noted: -contamination of the discs and/ or pads with oil (more likely on the rear brake, and easy to solve- remove the pads and hold them over the burner on the stove, and clean the disc with Dawn) -incorrect brake caliper for your type of brake lever (unlikely, but conceivable- the road-lever compatible Spyres are silver and black, while the MTB-lever compatible Spykes are all black) -pads too far from the disc (set them closer, so close that they almost rub, and then back them off if the levers feel too hard) -cable tension is low (loosen the cable bolt at the caliper, then move it up a little and retighten it until there is zero slack in the cable- you may need to reset your cable afterwards)

Answer 6

I have Spyres on a Orro Pyro and I can't say I'm that impressed with them. They are correctly set and not contaminated, but I suffer what I consider to be be poor stopping power. I'd fear for my life if I descended anything on the hoods. Descending anything above say 6%, I can slow the bike on the hoods, but not in a hurry. On the drops it is obviously much better but I'm not sure I could lock the brakes without Herculean effort. BTW, I'm 74Kg. Fitted as standard with compressionless outers. Have tried a variety of pads (organic / sintered) and not much changes. As with all these things there seems to be no common ground on opinion. My local LBS, that I think are very good, pour scorn on all mechanical disc brakes (mechanical and cable operated hydraulic). It's either Rim or full hydro for them - and they aren't trying to talk me into an upgrade as I know them well and have told them that is out of my budget. I was thinking about upgrading the rotors to 160mm, but they thought that would have very little positive effect. But then you have to contrast that with Orro themselves suggesting changing to 160mm being something well worth trying. Grey lines / semantics etc etc.