Cantilever brakes

[Stradageek]

Interestingly I decided to replace the Cantis with V-brakes on a bike build I'm doing.

Using the spare V-brakes in my bits box the problem I encountered is that the fork bosses were too short for the V-brakes. With a tight retaining bolt the V-brakes wouldn't move.

Is this a tolerancing issue or do some V-brake and Canti boss lengths differ?

[Brucey]

Avid shorty 6s (if they are like the ones I have) are probably best described as mid-arm cantis. They would be on my short(y) list for suitable brakes that would work with the OP's brake levers. Mini-Vs would, however, not be. Mini Vs work Ok with later model shimano STIs which have a lower MA (longer cable pull) in the lever.

The wide arm tektros are (as pointed out in a post above) a low-ish MA canti, and furthermore changing the straddle height doesn't alter the MA much. Mid-arm cantis such as the aforementioned shorty, shimano BR-CX50 and BR-CX70 have a higher MA to start with and furthermore this can be increased by lowering the straddle too. Any of those brakes will have a high MA and will work very well if fitted with decent brake blocks.


2012-on Avid shorty 6


older model shorty 6

The older model shorty has the same geometry and very similar performance to the newer one; the arms just look a bit different. The difference between shorty 4 and 6 is (IIRC) the type of brake block you get. If you want to run 'road' inserts in canti-compatible holders, best to get them with the brakes (as in the upper photo); they are expensive to buy separately.

FWIW canti bosses vary slightly in length. If you use a brake that has an integral pivot bushing, the exact length of the boss is almost irrelevant; it only matters for more basic brakes where the arm pivots on the boss directly. Br-CX50/70 and Avid shortys have integral pivot bosses.

cheers

[Sweep]

The wide arm tektros are (as pointed out in a post above) a low-ish MA canti, and furthermore changing the straddle height doesn't alter the MA much. Mid-arm cantis such as the aforementioned shorty, shimano BR-CX50 and BR-CX70 have a higher MA to start with and furthermore this can be increased by lowering the straddle too. Any of those brakes will have a high MA and will work very well if fitted with decent brake blocks.

mm - interesting brucey.

Thanks.

Am Nnot with the bike I had the frightening Dales experience with but it maybe has those brakes.

Set up by the folk who built the bike up.

And if so, confirms a general impression that although the bike is very nice (indeed) it was mis-sold/mis-specced for what I said I intended to use it for.

But I do like my Vs - two sets self fitted from scratch and it seems to me that if I can fit them from scratch without needing any tinkering there must be something inherently good about the system.

Do Vs have any disadvantages compared to the best cantis?

[Brucey]

Do Vs have any disadvantages compared to the best cantis?

yes; as previously noted most V brakes are easily damaged (in a way that isn't always obvious) if the steering swings to one side.

There is also a different range of brake levers for each brake type; this may affect your choice of brake as much as anything else, either because you like a specific shape, a specific shifter, or you just happen to own a set already.

cheers

[Sweep]

Do Vs have any disadvantages compared to the best cantis?

yes; as previously noted most V brakes are easily damaged (in a way that isn't always obvious) if the steering swings to one side.

There is also a different range of brake levers for each brake type; this may affect your choice of brake as much as anything else, either because you like a specific shape, a specific shifter, or you just happen to own a set already.

cheers

Have never despite my hamfistedness managed to damage a V brake brucey.


>>There is also a different range of brake levers for each brake type


don't understand this to be honest. Seem to reacall you saying that most Shimano V brakes were functionally pretty much the same

>>because you like a specific shape, a specific shifter, or you just happen to own a set already.

don't understand the reference to shifters. Gears rather than brakes?

[Brucey]

If you use STIs (for example) then you are stuck with whatever brakes will work with your STIs. This varies with the STI model.

Just because you have not managed to break a V brake doesn't mean that it isn't easy to do or commonplace; it is both those things.

cheers

[PH]

But I do like my Vs - two sets self fitted from scratch and it seems to me that if I can fit them from scratch without needing any tinkering there must be something inherently good about the system.

You can judge for yourself whether you think it inherently good - Seems to me the major difference is that poorly fitted and adjusted* V's still work reasonably well and that IME isn't the case with cantis. I use both, chosen on all sorts of criteria other than the braking - Levers, bars, light fittings, rim clearance, aesthetics and sometimes the choice has been made for me and I haven't felt the need to change.

*Edit - read that back to myself and it sounds like I might be suggesting yours are badly adjusted - I'm not!

[RickH]

Interestingly I decided to replace the Cantis with V-brakes on a bike build I'm doing.

Using the spare V-brakes in my bits box the problem I encountered is that the fork bosses were too short for the V-brakes. With a tight retaining bolt the V-brakes wouldn't move.

Is this a tolerancing issue or do some V-brake and Canti boss lengths differ?

When I switched the OEM cantis for Vs on my 1986 vintage Muddy Fox MTB I found the same - I had to leave the retaining bolts slightly loose. I ran them like that for quite a few years just checking periodically that the bolts weren't winding themselves out, which they never seemed to do. I did consider using threadlock but never got round to it.

[Stradageek]

When I switched the OEM cantis for Vs on my 1986 vintage Muddy Fox MTB I found the same - I had to leave the retaining bolts slightly loose. I ran them like that for quite a few years just checking periodically that the bolts weren't winding themselves out, which they never seemed to do. I did consider using threadlock but never got round to it.

Interesting observation Rick, I've often wondered how risky that would be but as most of my V-brake repairs are on bikes for charity sales I'm still scared of taking a chance

[pwa]

When I switched the OEM cantis for Vs on my 1986 vintage Muddy Fox MTB I found the same - I had to leave the retaining bolts slightly loose. I ran them like that for quite a few years just checking periodically that the bolts weren't winding themselves out, which they never seemed to do. I did consider using threadlock but never got round to it.

Interesting observation Rick, I've often wondered how risky that would be but as most of my V-brake repairs are on bikes for charity sales I'm still scared of taking a chance

I have cantis on a Thorn bike and if I do the retaining bolt up as tight as I can it will stop the brakes working. So I don't. And after many thousands of miles I have had no problems from that.

[Brucey]

if you can't tighten up the bolts without the brake binding there is something wrong for sure. It is best if there is an engineered solution of course, (and what you do on a bike that you ride is largely your own business, except to the extent that it endangers others ) but letting other folk ride bikes with loose brake bolts is completely unacceptable.

cheers

[pwa]

if you can't tighten up the bolts without the brake binding there is something wrong for sure. It is best if there is an engineered solution of course, (and what you do on a bike that you ride is largely your own business, except to the extent that it endangers others ) but letting other folk ride bikes with loose brake bolts is completely unacceptable.

cheers

It is probably a case of having a rummage in the parts bin. I got some new cantis, put them on a bike and did the bolts up tightish and they did bind. I took the new bolts out and installed the old bolts that went with the old cantis and they did up acceptably tight without binding.

[rjb]

if you can't tighten up the bolts without the brake binding there is something wrong for sure. It is best if there is an engineered solution of course, (and what you do on a bike that you ride is largely your own business, except to the extent that it endangers others ) but letting other folk ride bikes with loose brake bolts is completely unacceptable.

cheers

I've just encountered the same issue. Picked up a Ridgeback MX16 on flebay for my grandson. It's in good condition apart from the front V brake which was broken. No problem I thought as I have a box of recycled ones removed from skip bikes. I tried a couple of them and they protrude a couple of mm beyond the boss meaning they bind when you tighten the bolt. I am not prepared to run them with loose bolts, too much at stake here. So the options are, find ones with a shorter body, fit a version which has an internal pivot, or extend the boss using a short length of steel tube. ( My lathe could come in handy here). What is going on here. Don't brake manufacturers speak to the people that make the bosses!!!!!!
Do such things as brake standards exist or is the cycle industry still a free for all in the dark ages.