jm88

I made a post a couple weeks ago about getting my old Trek 820 back in shape as it has been sitting idle for over 10 years. I got it all cleaned and lubed up well and everything seems great except the rear brakes. When I pull the handle on the front brake, it pulls nicely, I can see the calipers pull evenly and stop the wheel, then retract properly when I let go. When I pull the rear, it feels a little different but mostly I notice the cable running to the rear across the top bar (inside of a thin jacket) seems to pull the whole thing (jacket and all) and almost spring and bounce against the top bar when I release it. ItAlso, the caliper does grab the wheel but seems to barely move and when I release it, it doesn't spring back like the front one does. I apologize if this is hard to visualize, but it just doesn't react like the front one does. I read about the Shimano Altus cantilever brakes with the plastic caps breaking and they are actually broken on both the front and back brakes. I tried adjusting the cable by giving it more slack or making it tighter where it screws in at the caliper but I am still not getting it to spring back like the front one. Does this sound like a caliper problem or a cable problem?

Tamiya

termv

Simple Test:

Take Off the cable. Squeeze the brakes. If the brakes return freely to their original position the brakes are fine. If not clean or replace.

However, I highly suspect that you have rust inside the brake cable.

Solution (obviously): replace the complete cable.

Also, front cable was also not used for 10 years.

So, just replace them all.

What about the shifter cable?

jm88

When I did remove the cable from the rear, the brake did spring back so I don't think anything is broken in there besides the cover. Maybe I will start by replacing the brake cable. It is a cheap fix and even if I have to replace brakes later down, it won't hurt to replace the cables. I have never done it but it looks easy enough. Is something like this set all I need? The shift cables seem fine and it shifts fine so I think those are alright.

termv

Yup. That will do.

Installation is easy. When in doubt watch YouTube.

capnjonny 

If the bike has been sitting for a long time you might want to disassemble the cantilevers and clean them. Doing this is easy. just remove the screw that is holding the arm to the stud and pull the arm off.
Before you do this look carefully at the brakes . often there is a tab on the stud with 3 holes in it. The spring inside the arm fits into one of the holes, usually the middle one. Make a note of where the springs go and put back in the same hole when re installing.
What these holes do is change the spring tension. If after many years the spring is week you can move it to the next hole to increase tension . Also some brakes have an adjustment screw in one or both arms. Screwing in increases spring tension . screwing out decreases tension. With everything cleaned and greased , operate the brakes. if only one side moves , increase spring tension on the other side (and decrease tension on the side that moves) till both arms move the same. If you have also installed new cables and covers your brakes should work perfectly.

Brian25

Frustrating!!! You mention that your Altus spring covers are indeed broken. I am familiar with that issue. As an ex store owner, I used to have a big bag of those plastic covers, because it's a frequent problem. The brakes will never work/ adjust without replacing them. before any thing else replace those bad boys!!!!

jm88

Are you saying replace the covers, or the whole brakes? Where do you find those covers? I also saw some videos on here about Shimano giving those covers out but they eventually ran out. The pads are rock hard (probably from being 20 years old), but they seemed to still stop ok. At least the front one since the back wasn't working!

jm88

I ordered that cable mentioned above and have a question. In all of the videos and instructions I watched, the cable goes from the lever to the front of the top bar in housing, a ferrule is attached and the bare cable runs along the top bar of the frame, connects goes back into housing at the rear all the way to the brake. Mine goes in housing from the lever to the front of the top bar, a ferrule attaches there but then the cable is run in a thin jacket all the way to the brake, going inside a metal tube around the seat post. I attached some photos. How do I run this new cable from where it comes out of that ferrule in the front all the way to brake? Should I just remove that thin jacket and try to put it on the new cable? Should I run it bare? There is place to attach a ferrule in the rear of the bike.

Cable running along top bar to rear brake.


Cable coming from lever.

Mr. 66

Your 820 is really clean, I'm thinking you do not have a cable issue. Can you take more pictures of the calipers, line and levers?

jm88

It is really clean now because I just cleaned it all up after sitting for 10 years. I'll take some pictures of it next week when I get home

jm88

A couple updates on this:

I think the cable is ok but one issue was in that jacket that runs the length of the top bar. It looks like it was catching on that hole that goes through the stem and I just pushed it back a little to a part where there was no gouge int he jacket and it seems to pull ok. When I pull the lever, it grabs the rim fine however I did notice one problem. The calipers will not center over the rim. The side where the cable goes has a big gap but the other side rubs a little. There is a screw for alignment adjust but since that plastic is cracked, it does no good. Would I be best off replacing the calipers?

Andrew R Stewart 

In the 1st post you gave your answer and a few have mentioned it also, the spring cover being broken won't evenly act on both arms equally. We see this a few times a year these days but back a bunch of years it was a few a month. While this doesn't effect the brake's stopping action it is frustrating to have one's brakes rubbing all the time. I still have a couple of replacement spring and cover kits but they are for when I find a bike I like that needs them, sorry. You might find a shop that still has some in their back stock.

The current fix is to replace the brakes, arms, springs, covers entirely. A low cost replacement set (one brake/one wheel) will run $10 to $20 typically, only slightly more then a new pair of pads and the new set will also have new pads. We stock Shimano's BR CT91 for this purpose. Andy

jm88

I don't know a whole bunch about brakes, but do see that modern brakes are either V-brakes or disc brakes. Just reading about V-brakes vs. the cantilever style I have, it sounds like V-brakes have the advantage. Since I am replacing them anyways (and I already bought new cables if that matters), can I or should I replace these with V-brakes? Or is there more to it than that?

cpach

You'll need new brake levers if you change to v brakes because they require more cable pull. It's not terribly expensive to get new levers with brakes so if your brakes aren't integrated with your shifters you may find it worthwhile. V brakes are generally a little easier to set up and work a little better, but traditional cantilevers work really well also. I like Tektro Oryx for an inexpensive cantilever because they use threaded V brake pads which are much easier to set up than smooth post cantilever pads and work well.

Andrew R Stewart 

The workaround for canti levers and linear arms is the Travel Agent. A cable routing pulley with two different cable groove diameters. The cable wraps around both diameters and the cable input travel is changed at the output side. Andy

cpach

Yeah, but with flat bars it doesn't really make sense. Adds another moving part and costs more than inexpensive v brake levers.

Andrew R Stewart 

We still don't know what style of shift lever this bike has. I agree that if it has separate shift levers and brake levers (as in each has it's own clamps around the bars) a Travel Agent is a bit more costly then just getting a pair of cheap brake levers. But if the levers are ganged together onto the same clamp then you'd also be buying the shift lever along with the brake levers.

My reply was to educate about options and not to say do this or that. Andy

samkl 

Absolutely right. The plastic spring covers are your problem, OP. Replace those or your efforts will be futile!

jm88

The brake levers are separately clamped onto the handlebars from the shifters and just briefly looking on Amazon, I see that brake levers are pretty cheap. Then wandering a little farther, I see integrated shifter/brake levers such as something like this for not much more. Mine has grip shifters which I don't think I am a huge fan of. Although it has been over 20 years since I had a different bike, and have not ridden much during that time, I did have one right before this bike which had rapid fire shifters and I seem to remember liking those better (that bike got stolen). The grip shifters do not seem like the most comfortable thing out there! I don't mind spending a little money on this since I am saving money by not taking it to a shop, but I just need to know where to draw the line so I am not spending more than what a new bike would be worth.

cpach

Good point.

OP: Some integrated brake/shifter units aren't a bad idea. You'll have to match the number of cogs/chainrings to the shifters but 7 and 8 speed integrated rapidfire shifters are still extremely common. Preference varies but I'd prefer these to grip shifters. Something like https://www.amazon.com/dp/B01FEWUVC0...&pd_rd_w=wk4gl would work well, and even comes with new der cables! I would recommend getting new derailleur cable housing while you're at it, and you'll need to buy brake cables and housing and brakes. Honestly most V brake/linear pull brakes work well--I'd stick to Shimano, Tektro, or Avid given that they make pretty affordable brakes. For the money I'd probably buy https://www.amazon.com/Shimano-BR-T4...himano+v+brake or similar.

jm88

Just to refresh my memory on how the rapidfire shifters work, do you pull one lever to go up/down and push the other to go the opposite way? Mine has 21 speeds so I'd have to get one like the one you mentioned with 7/3 but they all seem to be under $30. So with that and brakes, it's only going to be around $50 or so which is very reasonable. I already bought some brake cables so I have those to use.

When I run the rear brake cable, as I mentioned earlier there is only a ferrule at the front of the top bar as shown in the picture and the rest of the cable runs in that thin jacket or bare all the way to the brakes. That thin jacket is not like the other housings that remain stationary so it appears to be more protective as it moves with the cable. I don't know where I would find something like that so do I even need it? Can I run a bare cable through that tube near the stem? Or maybe just put this old jacket on the new cable?

cpach

If you change to V brakes you will no longer use any straddle cables so this won't be relevant. You don't need a cable liner from the stem to the cable straddle on the front.

jm88

I am not talking about straddle cables. I am talking about the main brake cable from the lever to the brakes.

cpach

OK, I see what you mean. That cable cover is totally unnecessary and I don't really like them. They can eliminate some cable slap against the frame but usually that's not really much of an issue anyways.