Canti brakes not good enough - change?

[jbstumpy]

If you want mini-v's Tektro RX5's are probably the best bet. Spa do them at around £15 a pair, so well priced.

I raised the post mentioned above. In the end I went with mini-v's although have a second bike with disc brakes. I personally really love disc brakes. They last ages, need little adjustment and run with a buckled wheel, and are exceptional in the wet. That said, they cost more, weigh more and I've yet to find a disc fork as comfortable as a nice curved fork.

My mini-v's are great too. However, a few things I find frustrating:
- Removing the wheel. You'll need to file down the brake noodle in so that you can unhook the brake in order to remove your wheels
- No inbuilt cable adjusters, you'll need to buy a set
- Limited clearance, I found getting my 45cm SKS mud guards under them a fiddly affair, but once done, they've been fine since.
- Compared to discs, once they're wet and there's grit in there, they just don't work as well.
- Compared to discs they require more attention to ensure they're always perfectly set.
- Damn they can be noisy if not set correctly! Safety bonus as it alerts *everything* around you.

Would I get mini-v's again. Yes until I find a comfortable disc fork, then I'm sticking with mechanical discs.

Thanks for the link. Disc aren't an option on this bike of mine. Thanks for the info on mini V's

[jbstumpy]

I would expect 20-year-old pads to be useless. That's the easiest upgrade, and will probably make a huge difference.

if they were (say) rubber that clearly degraded over time I'd agree. But they are not, they are 'something else'. They were rock hard on day one and they seem to stay that way. I agree 100% that they can likely be improved upon, but the original ones (good or bad) will probably be in the same condition in another 20 years....

cheers

The pads certainly do not appear to have deteriorated in any way - just rock hard, they seems to be quite a 'fiberous' pad.

[jbstumpy]

Brakes like this?



IIRC these are the same blocks as fit BR-M550, BR-M454, BR-M450, BR-M351, BR-M350, BR-M250 brakes. They were hard on day one.

The brake arms are IIRC 55mm long. The brake blocks look as if they could be replaced with 'V' blocks but in fact the bolt on most 'V' shoes isn't long enough for the thicker BR-M450/454 arm. On some cartridge shoes you can remove the bolt and replace it with a longer one + washers, but a small amount of engineering is required to do this. Once done, the brake will accept any cartridge pad though.

A simpler solution is to fit these;



but I've not BTDT myself, they may not give the correct spacing without washers etc. If they fit, they should improve the brake power. Several different compounds available.

Mechanical advantage of the brake is geometry sensitive. In a nutshell with these brakes the lower you can get the straddle wire the better. If you can space the brake blocks out to make the arms as wide as is practical, the geometry will change a little less harmfully as the brake comes on.

Note also that brake levers that pull enough cable for DP brakes pull a little more than is needed for these cantis, and this correspondingly reduces the brake power acheived. These brakes were originally paired with a long four-finger lever with a high MA on flat-bar bikes.

I'd try with a lower straddle cable first, then try brake blocks.

However you could just buy mini-Vs if you have DP pull levers and do it that way. Much less faffing about.

cheers

I have these canti brakes (though with the word Mountain on as well) and they do work very well with the MTB levers. I bought lots of cheap brake blocks, because they can be hard to find, that look the same, not Shimano, in France and they are nice and soft.
These pads are surprisingly deep, if I was to use the Eagles I would need to pack lots of spacers on the stud to avoid the canti arms being almost vertical, that may be due to my frame but I doubt it.

Yes mine have 'mountain' on them as well. Really intrigued as to weather I could obtain a set of softer pads as you did (without going to france). I am concerned that the Koolstops will need a lot a spacing, I am aiming to widen them as far as I can as per 'Brucey's suggestions.......

[jbstumpy]

I wonder if the Pads on my exage have hardened with age, they were new old stock (NOS) last year, 20 years old however.

Welcome to the forum.

I would expect 20-year-old pads to be useless. That's the easiest upgrade, and will probably make a huge difference.

Thanks for the welcome!

[meic]

Yes mine have 'mountain' on them as well. Really intrigued as to weather I could obtain a set of softer pads as you did (without going to france). I am concerned that the Koolstops will need a lot a spacing, I am aiming to widen them as far as I can as per 'Brucey's suggestions.......

They do come up occasionally and the good point is that when they do, they are very cheap as the shop cant sell them!
I bought all the pads the stall in France had, They were either 1 or 2 Euros a pair.
I had cleaned out my LBS's stock a few years ago.

Chain Reaction were selling some very cheap ones very recently called economy pads for something very cheap like £2 for 4, they have gone now. At that price it was worth taking a chance.

[pete75]

Nowt wrong with Tektro pads

[jbstumpy]

Lowered the straddle wire today and I am really surprised the difference made. Much improved. Noticed one of the pads making only 50% contact, so adjusted that also. The pads were a right faf to adjust. so far so good, going to have a ride out and decide wether to change the pads etc........

Thanks for the advice

[snibgo]

Thanks, Brucey, for putting me right on these blocks not becoming hard and useless with age.

I don't know what materials are subject to this. As well as my bike, my aged Land Rover had the problem -- the drum brakes became useless, and I couldn't find anything wrong. A garage said the pads were too old, replaced them, and all was well.

[Brucey]

I don't know what materials are subject to this. As well as my bike, my aged Land Rover had the problem -- the drum brakes became useless, and I couldn't find anything wrong. A garage said the pads were too old, replaced them, and all was well.

I don't know how all different materials 'age' either. But I've had new M-system blocks in the past and noted they were hard as nails (barely any thumbnail impression was my scientific test...) and I've got various old ones kicking about now and they seem little different TBH.

Brake friction materials for cars are a subject in their own right. I've done a little bit of work in this field. Pads can glaze over, the binder resins can degrade, the metallic components in the linings can oxidise.... all kinds of interesting things can happen.

I need to sort the brakes out on my landy, too. I've got discs all round (apart from the handbrake of course). Pads are easy, but discs are a faff, because they are bolted on the far side of the wheel flanges. ..

cheers

[NetworkMan]

I have old Shimano BR-M454s on my Dawes horizon (spaced about 65 mm apart at the front) and am almost out of suitable pads which are often also a little too thick to align properly. I tried a V-brake pad from some recently bought Tektros but as Brucey observes the thread is a little too short. The V-brake pad has two plano-concave spacers, one thin and one thick, and I need the thin one to get the spacing right which leaves the thick one under the retaining nut, but if I were to replace this with a second thin spacer the whole thing ought to work OK. Has anyone tried this I wonder? Is there a source of extra spacers apart from buying extra pads just to get them? Surely there are others with the same old brakes.

[Brucey]

pretty much every LBS workshop floor is decorated with V-brake spacers, so I'd try there if you can.

cheers