Replacing cheapo plastic mountain bike caliper brake systems

[sablewing]

I have just bought myself a super-cheap city runaround to get into town and back (There is little point leaving anything that looks expensive in town - there are high bike theft stats where I live, and it -or bits of it - would just walk.)

As in I paid just £10.... for the whole bike! It's an old Ammaco mountain bike, still in solid condition - the frame, the saddle and even the tyres, and though the rims are rusty a lot of it is cleaning up quite well. So I say the bike's worth a little bit more than I paid for it.

However, regardless of how intentionally crappy it looks I still want to make sure it's safe to ride. The brake setup is still the standard mountainbike caliper one that came with the bike, (see bottom photo) so is probably 10-15 years old.

The brakes still kind of work, the levers and calipers spring back ok, but all the cables are old and stiff, on the front brake it's permanently kinked on the metal yoke(?) so the cable doesn't sit in the centre, and keeps creeping back to the kinked bit, throwing the brake pads off balance. The braking power isn't great (even after adjusting the pads to toe them in, and also replacing the front pads)

The nuts and bolts are also rusty all over. What's also not nice is that the brake levers are nasty cheap plastic ones and are not kind to the hands! Also, due to the state of the nuts and bolts around the brake levers I'm not keen to press down on them too hard incase they break...

Questions -

1. Is it possible for me to replace the plastic brake levers with standard polished metal ones?
2. Would it be possible to replace the old cables myself too? If it would be too difficult for a noob, then how long would the new brake levers + cables replacement job take at a bike shop, and how much should they charge for the work?

I know it's a cheap, basic old bike by today's standards, but it would be nice to have a crappy-looking bike that I didn't have to worry about, AND that I could use safely without fear of dying... so it would be worth a few pounds to make it roadworthy.

Many thanks.

[DaveM]

Replacing the levers and cables shouldn't be very hard and will improve your braking. Note that you have "cantilever" brakes (not "caliper" and not "v-brake"). You need to get levers that are made for cantilevers, but there are all different kinds available.

Get decent mid price cables. They do work better than the cheap stuff and definitely replace cables and housing.

Better brake shoes may help as well. Kool Stop Salmons seem to be everyone's #1 choice. If your rims are steel, that will always make your braking a bit weaker than aluminum rims, especially when wet.

Note finally that toeing in the pads is done to get rid of squealing brakes. If you toe in too much in can actually hurt the stopping power a little, so don't toe in more than needed to keep the brakes quiet.

Not bad for $10!

[cyclerUK]

The front braking will be improved if you lower the "straddle" cable.
If you don't require the front reflector then take it off or move it.
Shorten the straddle cable so that the "yoke" is slightly nearer the tire (just about where the reflector bracket is).
This will give some more effort to cantilever arms and brake force.

You can do the same for the rear if nothing is in the way.

Sheldon Brown calls it "mechanical advantage".
:- http://sheldonbrown.com/cantilever-geometry.html

Basically the longer the straddle wire the less effort is applied to the cantilever arms. You can shorten the wire but it becomes impractical if too short and could even catch the tire.

[webj2001]

can anyone tell me if you can use a front disc caliper on the rear?

[X-RAY]

i have those exact same levers on my v-brake bike. i dont think they are correct for your caliper brakes.

[GeorgeET]

Hmm.. some interesting info from CyclerUK. Ye Sheldons site has lots of info. I am always finding more stuff.
From what I remember of engineering vectors 45 degree is optimal . I looked at my bikes and the cable angle in rear is similar to yours, the front is less. Never felt I had breaking issues. If your rims are steel there is only so much you can do especially when wet. Check if rims are magnetic if you do not know. Replacing pads would be the best thing to do first or at least dress them with rough sandpaper on a flat surface..

As far as replacing everything, why don't you go through the bike first spray some Liquid wrench on rusty parts and than wait a bit and remove and clean them. The parts look OK lubricate and tune everything well than see what needs replacing. For the cables you can take them off put a plastic baggie on one end and with cable end in it and cinch to cable with a rubber band, put in some lube and hang overnight till lube drips out the bottom, if not frayed this should help. I like using Tri Flow Teflon lube for general applications and liquid wrench for cleaning rust.

You can also service the wheel bearings first and than crank and head. Info on this site.

[Cheule]

Ahhhh a good old Ammaco Screwdriver, I used to love the paintjob on those, well, second to my Raleigh Amazon

A colleague at work has one and commutes in every day on it, yours actually is in better shape! I think what it needs is some good old love and attention and it will be back up to speed again

To answer your questions:

1) Yes! I've just replaced some Alhonga (who?) V-Brake levers with Shimano Deore's. Far, far and away more comfortable. The only thing to remember is you will need to remove the handlebar grips to slide off the old brake levers.

2) Any good LBS shouldn't charge more than £30 for the work (although they will charge for the new parts too) and take no more than 2 hours to fit. However you are on the LBS's schedule and you'll get the bike back when they say it's ready.

Alex does some great videos on the subject, the following should interest you:

http://bikeride.com/replace-cable-housings/
http://bikeride.com/inner-brake-cable/
http://bikeride.com/inner-shift-cable/

[cyclerUK]

(08-28-2010, 05:55 PM)X-RAY Wrote:  i have those exact same levers on my v-brake bike. i don't think they are correct for your caliper brakes.

I think you will find that, though the levers look similar, there is a difference.
"V" brakes require a different amount of cable pull than cantilevers.

I'm sure the above are the right ones for this bike. Having said that we have used standard cantilever brakelevers with "V" brakes when they first came out.

[GeorgeET]

I was curious about all this talk about cheap plastic brakes that for me lasted a long time. I got a setup similar to yours on one of my bikes by Shimano. The brakes work fine so the levers are OK as are the calipers.

Just for the hell of it I tested them with a magnet today and found that its a metal core encased in plastic composite. Thats OK with me they still work and are rust free on a 20 year bike.

Magnet is a good thing to have , very useful in testing spokes to see if they are high quality stainless.

Most stainless is non magnetic except some special application ones.

IMO if it aint broken don't fix it. We see lots of people here breaking things trying to fix working components. Guess thats the school of hard knocks. BTDT. :-))

However, customize as you chose. :-)) Brake levers are not expensive.

[Robb]

Well, hmm, for that weathered look, you just gotta keep those weathered parts, especially all that rust on the heads of those hex bolts. But that doesn't mean you can't remove those bolts, clean the threads, lube, and re-install. Just keep the rust on the heads as a theft inhibitor--nothing says 'you don't want to steal this funky bike' better than rust And I would angle those levers down from their present position--adjust to your preference--so they are easier to reach and pull.