I fixed cantilevers Forever. Trek 830

gag4o

Retro Newbie
Growing up in the 90s and early 2000s every normal 26" MTB and most lesser MTBs had terrible brakes - those cheap Diamonbacks and unknown eastern european bike brands that I rode. Rusted cables, worn out noisy pads etc I had to pull the lever so hard to barely slow down and most of the times I had to use my feet to stop by dragging them on the street or sticking foot between the rear tire and frame. Of course later on I figured It's mostly all due to bad or no maintenance at all and not the cantis themselves. But in my own mind cantis were way worse than even V brakes. I, nowadays love the easy and reliable stopping of hydraulic brakes but as I will explain I came back to cantis.

Last year I bought a very lightly used Trek 830 and looking at the cantilever brakes I kind of fell back in love with them. What cantis beat any other brake system for me is the LOOKS. I love exposed cables and cable actuated mechanical stuff. Here are a few inspirational pictures of cable usage.

Airplane avionics for small or older planes maxresdefault.webp


And some cranes
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I like how they have that ridiculous long and visible cables..I don't know, just fascinated.

Back to my project and my original idea to add second set of brake bosses. So I welded another set of brake bosses and a hanger that I cut off of another old steel bike i had.

This way looks better in my eyes and now it stops pretty much with double the force. I will maybe never ride this bike in actual rain or mud conditions. But I believe I do have better chances of stopping with a wet rim. Its just a project to have fun and in the first place I did save it from almost sure dumpster destiny.
I did tested the brakes and they feel great. They do not lock up immediately as I was first worried. Modulation is just as easy if not better than before. The new dual brake lever say short pull on the package so It is the right one for the job

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Parts so far
New and lubed cable housings
New SS cables 1.3mm
New short pull dual lever
New brake arm set Shimano BR-CT91 ($7 each set)

This bike will get new paint and many new parts I have laying around but when I do I will open another thread for the restoration only. I just ordered some parts so i should be this year I hope

I am planning on installing 7x grip shift, new cranks and 1x front conversion, new grips, stem (Girvin flextem) and handlebar
 
I have seen al those and I do have aluminum bike that the V brakes easily "stretching" and it is visible. HOWEVER this is steel frame and the flex is non visible at all. It may happen if I find a cheap used booster, they are all overpriced for me
 
I have seen al those and I do have aluminum bike that the V brakes easily "stretching" and it is visible. HOWEVER this is steel frame and the flex is non visible at all. It may happen if I find a cheap used booster, they are all overpriced for me
I'm surprised it's not flexing.
The braking power may be less than hoped - there's only the same leverage at the bar, after all. 🤔
 
Put some Scott Pederson front and rears on...the rim crushing force would be amazing
I did see few sets for sale recent month but I have heard they are not very reliable and stop on their own. They look good though

Still this is beyond the point which was to be able to have the cheapest crappiest $7 cantilevers be able to stop.
I can put Paul or something good and never need a second set as normal person would do
 
The force applied to the frame wont have increased, nor with the "crushing force" to the rim. You've increased the surface area over which the force is applied to the rim is all (2 sets of pads). you can only apply as much force as your hand can squish (or using a longer lever at either the bar or the brake as a modifier).

you could get the same from a longer set of pads, only they'd flex and thus negate some of the force.

a better set of pads with a high CF would have a bigger change but wouldn't look as crazy.

I'd do the maths, but I really can't be bothered :) something along the lines of combining these 3 calculations and knowing what you can squish with your hand will tell you the force at the frame and at the wheel from the pads.

(force) F=P*A
(friction) u=cf*F
(lever force) f1*r1=f2*r2
 
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