Retro Cantilever Brake Adjustment

nmfeb70

Well-Known Member
Location
Tonypandy, Wales
Hi everyone, I recently acquired a mid 90's GT MTB with cantilever brakes which now needs a cable adjustment (I've pushed the blocks inwards to the limit). I've included a photo and would appreciate any advice about the purpose of the small round disc and the sheath which covers part of the cable as I obviously cannot tighten it with these two as they are? Do these have any bearing on the cable adjustment? Thanks.
493780
 

Spokesmann

Keeping the Carlton and Sun names alive...
Location
Plymouth, Devon
One of the canti arms has an adjustment screw which can be screwed in or out to micro adjust the whole set up so the arms are equally angled and hence the blocks adjusted to the rim equally too. Make sure the brake shoes are set to the same position in the clamps as well.
 
OP
nmfeb70

nmfeb70

Well-Known Member
Location
Tonypandy, Wales
One of the canti arms has an adjustment screw which can be screwed in or out to micro adjust the whole set up so the arms are equally angled and hence the blocks adjusted to the rim equally too. Make sure the brake shoes are set to the same position in the clamps as well.
Thanks, so does the cable need any adjustment whatsoever ala V brakes?
 

SkipdiverJohn

Deplorable Brexiteer
Location
London
I would shorten the main front brake cable slightly and reset the shoes to give running clearance. Then I would fit a front reflector bracket through the hole drilled in the fork. Or fit those unbreakable MTB mudguards that use the same mounting hole. You don't want that straddle wire to ever be able to come into contact with the top of the tyre if you run on knobblys. Too much risk of coming off!
 
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mjr

Comfy armchair to one person & a plank to the next
Nothing to add to the adjustment advice, but please fit at least a front reflector bracket (or mudguards) to deflect a snapped cable before it catches the tyre, locks the brakes on and sends you flying.
 
OP
nmfeb70

nmfeb70

Well-Known Member
Location
Tonypandy, Wales
I would shorten the main front brake cable slightly and reset the shoes to give running clearance. Then I would fit a front reflector bracket through the hole drilled in the fork. Or fit those unbreakable MTB mudguards that use the same mounting hole. You don't want that straddle wire to ever be able to come into contact with the top of the tyre if you run on knobblys. Too much risk of coming off!
Good advice there about the tyres catching the cable, hadn't thought of that! How would I shorten the main front cable? Does it unclip from the small round disc? Cantilever brakes are a first for me.
 

raleighnut

Legendary Member
Good advice there about the tyres catching the cable, hadn't thought of that! How would I shorten the main front cable? Does it unclip from the small round disc? Cantilever brakes are a first for me.
That type of cable is an 'answer' to this problem,

I would shorten the main front brake cable slightly and reset the shoes to give running clearance. Then I would fit a front reflector bracket through the hole drilled in the fork. Or fit those unbreakable MTB mudguards that use the same mounting hole. You don't want that straddle wire to ever be able to come into contact with the top of the tyre if you run on knobblys. Too much risk of coming


It isn't a straddle wire, if one side breaks it's 2 wires that can't catch on the tyre. It was Shimano's answer to prevent that as the 2nd wire clips onto the main wire.
 

raleighnut

Legendary Member
It's a 'Y' type cable link, they are available in different lengths to change the angles the canti 'arms' sit at,

41pF8gaGVpL._SY355_.jpg

but were designed to stop the danger of the saddle wire snagging on the tyre.
 
OP
nmfeb70

nmfeb70

Well-Known Member
Location
Tonypandy, Wales
Hi everyone, I recently acquired a mid 90's GT MTB with cantilever brakes which now needs a cable adjustment (I've pushed the blocks inwards to the limit). I've included a photo and would appreciate any advice about the purpose of the small round disc and the sheath which covers part of the cable as I obviously cannot tighten it with these two as they are? Do these have any bearing on the cable adjustment? Thanks.View attachment 493780
Thanks all, but I still haven't got the answer I was look
One of the canti arms has an adjustment screw which can be screwed in or out to micro adjust the whole set up so the arms are equally angled and hence the blocks adjusted to the rim equally too. Make sure the brake shoes are set to the same position in the clamps as well.
There is only a screw on the front cantilever arm and turning it clockwise/anti-clockwise makes no difference.
 

raleighnut

Legendary Member
Thanks, but all I want to know is how to adjust the Cantilever Brake in the photo?
The answer was given upthread,

One of the canti arms has an adjustment screw which can be screwed in or out to micro adjust the whole set up so the arms are equally angled and hence the blocks adjusted to the rim equally too. Make sure the brake shoes are set to the same position in the clamps as well.
 

chriswoody

Legendary Member
Location
Northern Germany
Looks to me like your brake blocks are to far in on the arms. What your looking for is the inside vertical face of the arms to be parallel to each other your arms are noticeably leaning back from each other. When setting my canti's up, I sometimes go right back to the start and systematically set every bit up in order. Just found this video that looks like it will be far better at explaining than me trying to write it all out.

 
OP
nmfeb70

nmfeb70

Well-Known Member
Location
Tonypandy, Wales
Looks to me like your brake blocks are to far in on the arms. What your looking for is the inside vertical face of the arms to be parallel to each other your arms are noticeably leaning back from each other. When setting my canti's up, I sometimes go right back to the start and systematically set every bit up in order. Just found this video that looks like it will be far better at explaining than me trying to write it all out.

Thanks Chris, looks like I've finally got the answer I was looking for.
 

SkipdiverJohn

Deplorable Brexiteer
Location
London
How would I shorten the main front cable?
Depends where the outer cable is attached at the non-lever end. Your picture doesn't show enough of the brake system. Essentially, you need to either lengthen the outer cable using the barrel adjuster to pull up slack on the inner, or you need to raise the handlebars slightly, if the lower end of the outer cable is secured to the stem rather than the headset.
 
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