boneshaker78

Hello all,

Hoping the community could help me with my mechanical disc brake install. I’m accustomed to rim brakes, but have rarely dealt with disc and I want to feel confident installing these on my bike. Any advice would be greatly appreciated.

My understanding is that isopropyl alcohol should be used on the rotors. Torque to spec in the manual it came with, torque evenly alternating bolts on the rotors.. right?

One thing I noticed is that the mounting bracket for the front brake looks different and appears to be thicker than what was sent with the new TRP CX Spyres. Should I mount the bracket that came with the bike to the TRP or would the bracket that came with the TRP suffice? If I did change the bracket on the front brake, what kind of torque value should I use to attach it to the brake?

Thank you

FBinNY 

Generally I prefer to use the bracket that comes with the brakes rather than the one with the bike. This isn't based on hard science, but on a tendency to defer to the closest expert, in this case those who made the brakes.

boneshaker78

I agree, I’d rather use what came with it. Do you think the difference in thickness will cause an issue with where the brakes line up? Seems like it could.

FBinNY 

Could is very different from will.

In any case, you have both. Why not try both before deciding?

boneshaker78

Fair enough. Just trying to save myself some time and help the install go smoothly.

boneshaker78

Looks like the thicker bracket is designated for Promax brakes specifically.

FBinNY 

Save time, go with your instincts and call it a wrap, UNLESS you find a reason to consider the alternative.

boneshaker78

Got started on this project and decided to use compressionless housing. Any tips on using this housing? How to cut it? etc.. Very expensive compared to what I’m used to and I don’t want to cut or use it wrong. Thanks

AndreyT

Use good dedicated housing cutters. Install ferrules. Good cutters usually produce an adequate cut right away, but I personally prefer to follow it up with Dremel to ensure the end is perfectly square.

Keep in mind that compressionless housing is usually noticeably more rigid than classic spiral-wound housing, which means that it will often call for wider, more gentle curves, i.e. you'll need longer housing. Also, plan ahead and watch for interference with other cables and equipment, since once installed that rigid housing is much harder to get out of the way.

boneshaker78

I would use side cutter pliers for brake housing usually. What you are referring to is cutters for cables and compressionless shifter housing… correct?

This is what I typically use for cables and shifter housing.

FBinNY 

WARNING --- Compressionless housing is a bit of a misnomer. More importantly, it may introduce a hidden danger when used for brakes.

Conventional housing supports the compression load with coil on coil all steel support. However, the near lengthwise strands of gear housing are only kept from buckling by the plastic cover. Time and UV can degrade the plastic and lead to catastrophic failure under load. Of course, that failure is mist likely to happen during a hard stop when you probably need the brakes the most.

So, you have little to gain by using gear housing for brakes, and stand to lose more than the wasted extra dough

That said, there is long spiral rated for brakes. It does so by using specific structural elements to prevent buckling. Look for the maker to specify "suitable for brakes" or pass.

boneshaker78

Indeed. I certainly wouldn’t buy shifter cable housing for brakes. I bought Yokozuna Reaction compressionless cables designed for brakes. I guess I’ll just use my best judgement to cut them. It’s either no big deal or obscure enough that it’s difficult to find those with much experience cutting them.

boneshaker78

I found this kit and I think it might have worked out better. They appear to come with short lengths of cable to assist with the first turn out of road levers.

How stiff are compressionless brake cables and should they not be used to make the first turn out of road levers and along the drop bar?

Rick

Most of the compressionless Brake housing bought in kits comes with two short pieces Of traditional or old school housing. in sharp bends the round housing starts to flatten out or malform just enough to create friction on the brake cable. The Yokozuna Reaction Brake cable housing has the inner quality greased liner, the straight like piano wires and additional coil wires so this rubbing of the brake cable doesn't happen. The Yokozuna Reaction Housing is by far the stiffest I have ever used. I have only used it on my Paul Klampers with Paul Canti levers. These are made for flat style bars. The Klampers are really wide off of the frame and the angle coming of to the rear caliper is very tight. The brake cable coming Into the cable adjuster had enough friction that the brake handle had trouble returning to the open position. This problem was solved with a Jagwire insert style end cap.

Rick

In addition to the previous post. The Yokozuna Reaction Housing required extra care in preparation. I used quality bicycle cable cutters, a file, an icepick. The Jagwire insert style end caps come in 4mm, 4.5mm and 5mm. I happen to have some. I don't know what size they were. They were a little to small so I trimed enough of the outer coating to start them on and thread a cable through and used my Hozan 4th hand brake tool. There are Youtube Videos on cable prep also.

FBinNY 

You can cut this housing with any shear type cable cutter. The same "passing V's" action that prevents fraying will keep the housing round. You'll need a sharp point to pick the liner open, and may want to file the end square, but usually don't need to.

Want doesn't work well is diagonal cutters or anything similar, intended for solid wire.

boneshaker78

Perfect. These were the answers I needed. Looks like I will purchase the TRP kit designed for drop bars and use proper cable cutters. Thank you everyone.

AndreyT

No, they are not "only kept from buckling by the plastic cover". Nobody makes compressionless brake housing like that. The enabling technology that made compressionless brake housing possible is Kevlar sleeving. Compressionless housing contains a layer of Kevlar reinforcement, which is specifically there to prevent the problem you are describing. Without an extra layer of ultra-strong material providing the necessary reinforcement, compressionless brake housing would not be possible.

FBinNY 

Check the depth before diving in.

This is the last line of the post you quoted (which you conveniently left out).
That said, there is long spiral rated for brakes. It does so by using specific structural elements to prevent buckling. Look for the maker to specify "suitable for brakes" or pass.

I posted the warning because the OP mentioned "compressionless housing" with being specific. This was made for gears for about 2 decades before a brake compatible version was introduced, It was fairly common for folks to this for brakes, without knowing the problem.