Help diagnose my brake issue

[russd32]

I built up a '13 All-City Space Horse not too long ago and the brakes suck. I'm not sure if I need to dial something in different, or replace some parts. The rear brake has very little power, even if you grab a handful it just feels like it's not doing much. Also, the lever acts like it sticks...so when you first grab the lever it kinda pops like it's becoming unstuck. The levers are 105 5700 series and the cantis are Cane Creek Shorty 4's.

What do you think? Try new pads? Ditch the Shorty 4's completely? Cables?

[DfCas]

Try some Kool stop salmon pads and check out Sheldon Brown's canti brake treatise at Harris cyclery.

[Dead Man]

I can't really be of much help other than to sympathize... cantis SUCK. Hard to get set up right, and they don't stop for crap unless you get them perfectly dialed in, if then. Maybe if you drop big bucks on expensive ones, they work better. I've not been able to bring myself to spend more money on a style of brakes that's known for sucking, though.

Mini Vs are where it's at, for non-caliper bikes.

[PSC]

Have the same bike w/ Tektro 720's. I swapped pads for Koolstop salmons and I use a fork mounted cable hanger. Braking is good, not great.

[RobJ]

The sticking issue almost seems like a cabling problem. That the cable isn't moving freely in the housing. Did you use new cables and housing? Any chance their frayed? Or us the cable catching somewhere in the lever? For the power problem check that you don't have the straddle cable too long.

[David Kirk]

canti's are super fussy in regards to the straddle cable length.....if that's not right the rest of it is moot.

The pop noise in the lever is likely caused by the barrel on the end of the cable binding in the hole in the lever. If you can slowly squeeze the lever and watch it carefully I'd be surprised if you don't see it suddenly release and rotate. A drop of chain lube should take care of it.

hope that helps -

Dave

[Peter P.]

I like Dave Kirk's suggestion about the lead cable end.

I wonder if the levers aren't a good mechanical advantage match for the cantilevers.

It might be worth trying a V-brake with a Travel Agent instead.

[marciero]

One other thing to check regarding the sticking is whether the top of pads come in contact with the tire as you squeeze or release the lever. This can happen especially with wide tires and narrow rims. Sticking can also occur when the pads are rotating downward when they contact the rim, and sort of get wedged against the rim. Both of these result due to the the canti brake arms moving in a circular arc when actuated, rather than traveling perpendicular to the rim throughout actuation.

In all the discussions on canti vs v-brake vs whatever, no one seems to mention how the rim plays into it. I have found vastly improved performance, including elimination of squealing and judder, when I changed rims. I believe this is due to a difference in rim width as well as better machining of the sidewall. Different rim widths can have the affect of changing the mechanical advantage, again due to the brake arms traveling in circular arc. One other thing that is not talked about so much is that the stiffness of the fork (or rear stays) plays a role in the performance of canti brakes.

As DfCas said-DO use Koolstop salmon and DO check out Sheldon Brown's article.

[russd32]

Thanks for the replies everyone! Upon further poking I believe the diagnosis of a craptastic cable is to blame. I put this thing together with spare parts and I used some cheap cable I had laying around my shop. I think it's either compressing, binding up, or something not good. I'll pick up some decent housing to replace it before I do much else.

Replacing the pads probably isn't a bad idea. After doing the cable I'll probably order a set for good measure. Hopefully that'll get it stopping at least comparable to my road bike

[catchourbreath]

Also make sure your cutters are leaving a nice clean edge on the housing and cable. Use something to poke through the cut end of the housing to ensure that no bits of the metal housing rub the cable.