Hewitt Cheviot cantilevers

rampax

I got a Hewitt Cheviot SE a couple of years back, and to be honest I have always been underwhelmed by the braking. Looking around it seems this is quite a common thing.
Mine is fitted with Tektro CR 720 Cantilevers, and STI levers.
At the moment it requires quite some strength to bring the bike to a stop, sometimes this gives an unpleasant fork judder at low speed.
Descending long steep climbs can leave my forearms aching.
I assumed these blocks would bed in over time but I have not really noticed any difference.
I am getting it ready for its first tour, so as I will be panniered up I need the braking to be at least satisfactory.

Is there a brake block I can fit that will radically improve this existing setup?

Monty Dog

Firstly, make sure the brakes are set-up correctly, with canti brakes the length and angle of the straddle wire is critical - if too long, you get very spongey braking. Also make sure you have a decent quality cable outer. Suggest you look at a soft-compound pad like a Koolstop Salmon, even better with a cartridge-type holder which tends not to flex as much as a one-piece pad.

mercia_man

Koolstop Salmon pads should be a big improvement over standard. They are what I use on my tourer.

I think your brakes probably have cartridge holders already so you just need pad insert. Toeing them in slightly at the front edge of the pads can help reduce judder. The straddle wire should be adjusted so it has a 90 degree angle where it is pulled by the brake cable.

rampax

Ok, I have attached a photo of the setup. This isn't at 90 degrees to the callipers, but I can't see how you could get it there - the blocks are nearly touching the rim as it is?
Also, the blocks are the "all in one" type.

BigLee1

Nice retro brakes I`d be really tempted to try some V brakes, I'm only guessing they`d fit but they are cheap to buy. Good luck!

mercia_man

The 90 deg angle for straddle cable is not where it meets the brake arms, it's where that stirrup thing holds it above mudguard. It looks about right on your pic. You could perhaps undo cable bold on stirrup and move it slightly up along cable but it's not vital.

As for the blocks, done a quick Google and it appears new brakes like yours are fitted with cartridge pads. I believe yours are cartridge pads because I can see the little screw which holds the pad firmly in the cartridge holder.

You can take them off and compare with what's available. I guess standard V brake pad inserts would fit your cartridge holders. You can get Koolstop Salmon or dual compound (black and salmon) to fit most brakes.

Have a look at http://www.dotbike.com where they have Koolstop MTB threaded V brake pads in standard or slimline for close clearance frames like touring bikes. I reckon that's probably what you need. I have bought plenty of stuff from Dotbike - good quick service. If in doubt, ring them or touring specialists Spa Cycles who sell bikes with your brakes.

pete.whelan

got these brakes on our tandem and never had a problem with them.

mercia_man

A couple of further points. Looking at your pic you don't appear to need slimline pads on the rear. It may be a different matter on the front because the forks are closer together although I suspect standard could well be OK.

If you move straddle stirrup up the brake cable it will pull pads closer to rim so you may have to loosen bolt where straddle cable meets right hand cantilever brake arm so as to get a bit more slack (ie lengthening the straddle wire a touch) and then re-tightening. You may however be able to adjust the distance from rim sufficiently by using the cable adjuster on the frame cable hanger. Just edited: on second thoughts I wouldn't bother moving it. Too much hassle!

mercia_man

Yet another thought! Just done some more research and it seems Tektro CR 720 cantilever brakes have a cartridge holder that takes 55mm pads - shorter than the usual V brake pads which are 70mm long and curved to match the rim.

So you need inserts to fit a 55mm holder which is the same as a standard Shimano fit road bike. Take them out and have a look and I reckon you will find the Koolstop salmon pad insert for Dura Ace/Ultegra/105 will fit. The pad inserts have a little indentation on the back where the retaining screw goes.

You could also buy pads and cartridge holder that are 70mm and fit them but I think the straightforward replacement 55mm inserts are the answer.

rampax

Cheers for being so thorough!
Ok, I will take one of these apart to make sure, but it's sounding like I am after these then:
http://sheldonbrown.com/harris/brakeshoes.html#vrefill
The BRK25 "refills"
That semi circular nook on the back, is that for the retaining screw?

mercia_man

Feel I went on a bit too much! But I was initially confused as I hadn't expanded your pic for full view.

Yep those are the ones. Wiggle have them in stock £8.99 a pair. That nook is for the screw. The inserts can be a bit tough to get out. Undo the retaining screw and push them out with something like a screwdriver. Those salmon pads work really well on my cantilever brakes and have a plough tip for correct toeing in.

Monty Dog

You've got standard road-brake size pad holders - swapping to an MTB Vee-brake holder will allow you to use bigger pads. For cheap Vee-brake cartridge holders, try International Bike Disc seller on ebay.