How to remedy spongey brakes
 

Cross posted with the Classic and vintage forum

Ever since I finished my Mercian I have had one nagging problem... spongey brakes. I mean really spongey... like coaster brake spongey. I ride in the rain and had to drag my feet on the ground going down hill towards an intersection.

Here is why this seems so wrong. I have modern Dual pivot calibers, aluminum rims, modern aero brake levers AND really fancy kool stop cartridge pads. I have cleaned the rims and pads with alcohol on more than a few occasions.

The only thing I can guess is that the no name old brake cable housing is to blame... the inner wires are stainless steel.

I recently installed these new calipers with no positive effect:

Tektro R559
http://farm7.static.flickr.com/6160/...e89700a7_b.jpg

Here you can see the kool stop pads:
http://farm7.static.flickr.com/6090/...92cd59bd_b.jpg

mkeller234: What kind of brake levers do you have? Caliper brake levers and v-brake levers have differing amounts of cable pull and mechanical advantage and need to be matched to the brake type.

Are the cable housing ends properly prepped (cleanly cut with ends filed flat) and the correct metal ferrules installed on all cable housing ends?

Those are long-reach calipers and it looks like the brake shoes are all the way at the tops of the mounting slots. Are the shoes centered on the brake tracks and contacting the tracks squarely? If the shoes are not parallel to the tracks they will not make firm contact.

The brake levers are tektro 200a, which I believe is the correct lever.

I do file the ends of the cable housings so that they are flat. However there are 2 things that I can think of being wrong with the housings. 1) the front is too short because I raised my stem after installing the cables. 2) They are new... but they are probably very old and cheap considering where I bought them.

-The calipers were a flub on my part... I measured incorrectly. The pads have do run parallel and centered on the rim surfaces... but just barely. It was pointed out in another thread that maybe the performance is suffering because they are higher than they ought to be.

they're long reach ? or so it appears..

Get the cables right then see where you're at. If the cable is too short and you pull the lever, it may have nowhere to go leaving you with little or no braking. I see brakes all the time that have poorly routed cables, or a system with excessive friction causing poor performance. Even some of the cheapest wally world components can be made to perform adequately.

Do your brakes "spring back" right away after you release the lever or do they slowly return and stick?

http://sheldonbrown.com/cables.html

They spring back very nicely and I don't have to pull the lever far to get the caliper moving. I think starting with the cables is a good idea considering that is cheaper. Jagwire seems to have a good reputation, I think I will look for a set of those tomorrow.

Toe-in was suggested to me in the other thread. The kool stop pads have that round adjustment bit on them and I believe the sit completely parallel to the rim surface. I'll try to get those angled a bit to see if that helps any.

Yeah, that was a mistake on my part. I could replace them and use the long calipers on another bike... but that will be my last resort I think.

I grabbed a penny and adjusted the toe-in. I'll see if that makes any difference on the ride home. I should have done that from the start.

mkeller234: Toe-in won't make your brakes any firmer, probably less so. Are the cable ends correctly and firmly seated in the levers and are the correct type of end? Most brake cables come with 2 different ends and you cut off the one you don't need. Are you using the right end?

If you have drop bars where the cable housings run under the tape, the housing MUST be properly seated in the levers before you wrap the bars, otherwise the housing will move under the tape when you apply the brakes, until it finally comes to a stop in the lever socket.

Don't ride this bike until you get the brakes right.

Brakes (and tires to a lesser extent) are the last places I would try to save a buck. Get some top-notch cables and install them carefully and correctly and you will save yourself a world of hurt, maybe literally.

Well, I did ride the bike home from work this morning... in fairly heavy rain. The toe-in did seem to help a bit, I was able to stop going down hill where I normally dragged my feet. I'm going to replace the cables today... probably with something like shimano or jagwire, whatever the lbs has.

Yes, I do have aero levers and housings and I made sure the cables housings firmly contacted the levers. I did that by setting the brake up, then squeezing the lever and taping the housing with electrical tape while under compression. I also file the ends of my housings after I cut them.

Actually having the pads at the very top of the adjustment slot gives you the best mechanical advantage so that isn't part odf the problem as long as the pads align properly with the rim.

One thing that might be happening is the housing (at least the cheap old stuff I have seen) is like a big coiled spring and if it gets stretched out, then when you apply the brakes it squeezes together and you don't get much braking. See if the housing isn't sprung apart somewhere.

Cables AND housing. The one is only as good as the other. And by your own admission you went cheap on the housing. Also if the housings are "tight" going to the caliper you won't get the same support for the cable as when they are in a proper short but loose and flowing curve.

Jagwire makes decent base model stuff but if this is your daily rider I'd suggest going upscale for housing by a step or two. No need to buy high end boutique stuff but something better than the basic bulk stuff WILL make a difference.

+1 that toeing in the pads will actually make things more spongy. For the most firmness, they should be flush with the rim.

BCRider, I agree that the better cables and housings really are better, but the really good stuff isn't necessary to achieve reasonable braking. Clearly, the OP is having a more serious problem. I was going to suggest that the housing wasn't pushed into the brake levers enough (common problem) but the OP said that was not the case.

First off, thank you to everyone for the helpful advice!

So I did buy new brake cables and bar tape today/ Performance has an exclusive deal with clark's brake cables, so that is what I ended up with. I've never heard of them or used their cables before. I installed the cables (sans those goofy red cable hotdogs they include) and took it out for a short ride... i'm talking 2 miles short. I'd say so far so good, the front brake is very much improved... I can stop abruptly, enough that the whole caliper flexes forward in a kind of scary way. The brakes are easy to actuate and feel more solid than before. I'd say the rear is a wash, no better no worse... but then it's the rear.

I jacked the stem way up and kept the cables long. I can trim them shorter if I want but this time I won't be trapped into keeping the stem low.

Here is the old cable, you can see how short the front is. If I turned the handlebars far enough it would actuate the break.
http://farm7.static.flickr.com/6176/...2f1368f3_z.jpg

See, I told you I finish my cable ends!!
http://farm7.static.flickr.com/6163/...2c08e58b_z.jpg

New cables installed and left long. I had my choice of black, black and black. I dont think the red fizik tape looks as tacky as I was afraid it would. Some red electrical tape is definitely in order.
http://farm7.static.flickr.com/6167/...86f8e61f_z.jpg

No need for the red tape. The black sets off the black hoods nicely.

I personally like a contrasting tape and red looks good on about any bike especially fairly subdued colors like yours. I think it looks great and actually might not look as good w/ red trim tape unless it matches the handlebar tape exactly. I trim my red tape w/ black for that reason (plus my bike and handlebars are black)

PS: how do you pronounce Mercian? I always thought it was "MER see un", but the only person I actually know who rides one pronounces it "MER shun".