Cantilever brakes

[nashd]

I've bought set of wide mudguards for a Moulton TSR.

Installation got off to a bad start due to receiving incorrect instructions for one part of the job, and no instructions for another.

Anyway, I eventually got around to attempting to fit the front mudguard, only to find that there's insufficient clearance for the front brake.  The brake is a Paul Components MiniMoto, which is a mini V-brake.  The cable between the two arms rubs on the top of the mudguard, and the drive-side arm presses against the side of the mudgard and knocks it when the brake is applied.

I'm contemplating buying a cantilever brake, but due to bad experiences with cantilevers in the past, I'm dithering about buying one.  Online reviews don't help much - opinions range from 'terrible' to 'better than discs', and all the theory about mechanical advantage makes my eyes glaze over.

Paul recommended their 'Touring' model.  Of course, there are other options from Tektro, Avid Ultimate Shorty, Shimano CX50, and Rene Herse, etc.

I'm also not sure about cable hangers for the Moulton - there's a long drop from the stem to the fork crown, and the canti bolts are on the stirrup fork, so they're quite a bit in front of the stem. It looks like it won't be a straight drop from the hanger down to the brakes, so the cables will be exiting\entering at an angle.

By the way, the bike is configured as a fixie (no rear brake caliper) with drop handlebars.

Other options include buying a standard V-brake with a Travel Adapter, or replacing brake levers with V-brake compatible ones and using a standard V-brake.

I'm not sure of the best way to go.  I didn't expect to run into this problem!  Perhaps the best thing would be to give up on the idea of mudguards...

[LittleWheelsandBig]

Because of the front suspension, the cable stop for a front cantilever must be attached to the fork stirrup. Otherwise your front brake stops working when the front suspension compresses. I don’t know if your TSR has a bolt hole on the fork stirrup but that is also where you need to fit your front mudguard.

https://www.edinburghbicycle.com/tektro-fork-mount-cable-hanger is one version.

Depending on how much clearance you need to fit your front mudguard, you can:
- Fit a slightly longer mini-V. Arms 5mm longer might be enough. There is a range of mini-V arm lengths from e.g. Tektro.
- Fit a full-size V-brake and matching brake levers or a Travel Adaptor.
- Fit a cantilever brake and bolt on a fork crown cable stop. These cable stops were commonly used by cyclocrossers when they used cantilever brakes.

[BFC]

Fettling of the mudguard could be a better solution - depends on material but cutting/grinding or bending of material out of the way would leave you with a brake you trust which is a key consideration with front brake only fixed set ups (I have run a few!).

[nashd]

Thanks very much!

I had been thinking about buying a fork crown mounted cable stop, but didn't know a stem mounted one wouldn't work because of the suspension.  Physics was never my best subject!

Yes, my fork stirrup is threaded, and the Moulton wide mudguard boss kit includes a spacer which is screwed onto the top of the mudguard, and then secured with a long bole to the fork stirrup.  If I got the Tektro stop would I put that in front of the mudguard boss (ie stirrup, then mudguard boss, then Tektro stop)?

 I hadn't actually thought about looking for a mini V-brake with longer arms.  Documentation on the Paul site says the height of the arm is about 78mm, but it could effectively be less than that due to the curve of the drive-side arm:-

[nashd]

Thanks, BFC.  I might take a closer look at that, too, but I think things seem quite tight.

Like you, I really place a lot of trust in the front brake of a fixie.  My last one had a Dura Ace dual pivot caliper with Swissstop pads, and it was brilliant - even on really steep descents in the wet.  The problem is not knowing how a brake will work until you've tried it, and some of the cantilevers are quite expensive.  Paul said their Touring cantilever would be a good option, but not as good as the brake I already have - I'm not sure what that means, but if it means I'd need to really squeeze the lever hard then I'd prefer a better option.

[LittleWheelsandBig]

My Moulton Stowaway is set up as 56x13 fixed with no rear brake. Make sure your rim tape is not heat susceptible otherwise a long steep descent could be a problem. DAMHIKT.

[nashd]

I've had a look, and seen that the Tektro RX-6 mini-V brake has arms which are 90mm long. 

I'll measure up when I have a chance, but perhaps these are the sensible choice! 

Are they good brakes, or to be avoided?

[nashd]

My Moulton Stowaway is set up as 56x13 fixed with no rear brake. Make sure your rim tape is not heat susceptible otherwise a long steep descent could be a problem. DAMHIKT.

Oh, that's another thing to worry about!  Especially with the small wheel, even if a TSR's is slightly larger than a Stowaway's!  I have a drum brake on the front of my F-frame, but I've not taken it down any really long, steep descents. 

[Paul H]

The Paul Components Touring looks very nice, particularly in the polished silver bling version, It works just as you'd expect a good quality canti would. It's no better, possibly not quite as good, as a Shimano full size V brake (I've had several versions and don't notice any difference). What I have noticed is the cantis require more fettling to keep working well, whereas the V brake is pretty tolerant of not being set up perfectly.
That's my experience based on changing from the V brake (With Cane Creek brake levers and bar end shifters) to the Touring (With Campag Ergo) everything else remained the same.

[LittleWheelsandBig]

I have a RX6 mini-V on the front of the audax tandem (I think, need to check). It is cheap but works well enough with Koolstop Salmon pads. I replaced the flexible guide pipe with a rigid pipe with an adjuster.

How much more room do you need? If the arm length gets close to a full size V-brake, you are going to need a V-brake compatible brake lever.
https://www.gravelbike.com/v-brake-arm-lengths/amp/

[fruitcake]

Travel adapters can work well, with the only drawback being they make it fiddly to replace cables. I've found the same problems as described in the OP even with standard v-brakes on a bike with 2" tyres and 60mm mudguards, so going to full v-brakes is no guarantee of success here.

It should be worth persisting with the cantis, if you can bear to.

The low profile design as fitted to MTBs in the early 1990s are tricky to set up and can be ineffective, which is why touring cyclists and tandemists used wide cantis or frog leg cantis which were much easier to adjust to the recommended 90 degree angle for the straddle wire. Brake blocks with softer rubber can make enough difference that an ineffective brake can become effective. (Not Shimano brake blocks which were famous for being poor.)

Those canti brakes made in the last couple of decades, and marketed for cyclocross bikes, can be very effective.

Additional benefits of cantis are that they work with standard drop bar brake levers and that the brake blocks generally last longer than v-brake blocks.

[nashd]

Thanks, everyone.

I don't think I would need to much additional height in order for the link cable to clear the mudguard.  I think the RX6 or even the Shimano BR-R353 (in that list) would just about do the trick.  They don't have the curve of the Paul brakes, so I think it's less likely the arms will foul the mudguard.  I think they're both mini V brake, and are meant to work with road levers, so perhaps 85-90mm arm length is the cut-off point before needing V-brake levers.  Thanks also for the tip about using a rigid pipe with adjuster.

The more positive comments about the Paul Touring canti are making me reconsider them, too.  That's a lower profile canti, but the one Paul recommended.  He said to fit the mudguard and then adjust the straddle wire so it's as low as possible.

[WOT]

Cx-50 or even better cx70 as they use standard road pads. Super easy to setup, work perfectly.

[DuncanM]

It looks like Shimano discontinued the cx70 canti brake.

I've been hunting through canti brake options recently because my cross bike has oldis Avid Short 4s on there, and they aren't brilliant. Plus the fork is a bit flexy so I get lots of judder - the nicer canti units have much simpler adjustment meaning you can keep them in better fettle and reduce the judder. The problem is, the nice ones are super expensive. In general, low profile ones are harder to set up and have less mud clearance, but have much greater power than the super wide ones - pick your poison. Personally, if I could get the clearance with mini-V then I'd go with them...

[Paul H]

The problem is, the nice ones are super expensive. In general, low profile ones are harder to set up and have less mud clearance, but have much greater power than the super wide ones - pick your poison.

The Paul Touring, like the discontinued Shimano, could be considered mid-profile, or low profile with longer arms, giving a degree of flexibility in the set up.
Have you come across the VO ones? Not cheap but you get a pair for the price of a single Paul Touring I haven't tried them, but they look like they'd be a good choice, they also have the cable adjustment on the straddle wire, which ought to make keeping them well adjusted easier. 
https://freshtripe.co.uk/velo-orange-grand-cru-zeste-cantilever-brake/

[DuncanM]

The problem is, the nice ones are super expensive. In general, low profile ones are harder to set up and have less mud clearance, but have much greater power than the super wide ones - pick your poison.

The Paul Touring, like the discontinued Shimano, could be considered mid-profile, or low profile with longer arms, giving a degree of flexibility in the set up.
Have you come across the VO ones? Not cheap but you get a pair for the price of a single Paul Touring I haven't tried them, but they look like they'd be a good choice, they also have the cable adjustment on the straddle wire, which ought to make keeping them well adjusted easier. 
https://freshtripe.co.uk/velo-orange-grand-cru-zeste-cantilever-brake/

I'd seen them online - they look a lot like a shiny version of the TRP RevoX cantis that were the main alternative to Avid Short Ultimates when the 'cross world was running cantis. I didn't realise they were £135 a pair, I thought that was per wheel. At that price they are almost good value for something so shiny!

[nashd]

Thanks for the additional suggestions.

I'm still undecided.  I'll need to have a closer look at the bike in the daylight sometime to see how a crown-mounted hanger would combine with the mudguard boss.  I'm not sure about fore-aft cable angle, and the VO brakes look like they have quite tall arms, so the straddle wire might end up really close to the cable hanger.

If it all looks a bit uncertain I'll probably just buy a cheap mini V-brake and see how I get on with that.

[iandusud]

Hi, You don't say what brake levers you are using. This is relevant 

[nashd]

Hi, You don't say what brake levers you are using. This is relevant 

I've had a wee look, and they're "Shimano Exage Action". 

[DuncanM]

A question about canti brake pads/blocks, hopefully it's not too off-topic.
I think I've discovered why  my brake judder is so bad. Currently I have these pads:
2021-11-05_03-55-24 by duncancmartin, on Flickr
You can move the insert back and forth inside the holder by around a mm - the split pin stops them falling out but doesn't hold them solid. I assume I should replace them - is there a specific setup I should look for? Price isn't an issue (within reason) as this is a CX bike, and the judder makes it basically unrideable.
Edit - alloy rims.

[LittleWheelsandBig]

That probably isn’t the issue. Front cantilever brake squeal can be caused by a lot of things but it is often a flexible forks versus headset-mounted cable stop problem. As the fork flexes backwards, the brake cable tightens, the pivots flex outwards easing off the brake and the fork flexes forward. Combine with the difference in static and sliding brake pad friction and repeat at a high frequency. A fork crown cable stop usually improves things considerably.

[DuncanM]

That probably isn’t the issue. Front cantilever brake squeal can be caused by a lot of things but it is often a flexible forks versus headset-mounted cable stop problem. A fork crown cable stop usually improves things considerably.

I've seen that mentioned, but there's no hole for a fork crown mount, and I don't want to drill the carbon! New brake blocks are worth a go, before I have to start considering a new fork (or dealing with mud issues from mini Vs)!

[LittleWheelsandBig]

I would use a road-length brake pad (tend to be thicker) and add some toe in. It can be tough toeing in a MTB-length pad.

[iandusud]

Hi, You don't say what brake levers you are using. This is relevant 

I've had a wee look, and they're "Shimano Exage Action".

OK, then if you wish to use linear pull brakes I think you will need short ones. OTOH I have recent Tiagra brake levers (SSLR) on our tandem and they work very well with full length linear pull brakes.