Bicycle Mechanics - Cantilever Brakes - Cable Question

I have late 80's MTB with Shimano DX cantilever brakes in which the main brake cable connects to one of the brake arms and the other brake arm is connected to the main cable with a short cable (barrel end x compression clamp).

After many attempts and once by LBS I cannot seem to ever make both cantilevered brake arms move in a mirrored synchronized manner. To resolve this I was thinking of installing a single cable both cantilevered brake arms to form the upside down "V" and then connect the upside down "V" to the main brake cable with a cable connecter.

Now for my questions.... do you recommend doing this? Or am I just not setting up the existing system properly?

The brake cable moves freely within the little housing there is. I hope you were able to follow my description.

PS Yesterday was the first time I was able to ride outdoors since I broke my collar bone 6 weeks ago (went down while riding in the rain). My shoulder is a little sore today but it was nice to get off the stationary cycle.

your brakes might have a small adjusting screw on one of the cantilever arms. this screw adjusts the return spring tension. fiddling with it will probably get your brakes working the way you want them to. if they dont have the small screw than the brakes are probably low end so you might want to upgrade.

I have late 80's MTB with Shimano DX cantilever brakes in which the main brake cable connects to one of the brake arms and the other brake arm is connected to the main cable with a short cable (barrel end x compression clamp).

After many attempts and once by LBS I cannot seem to ever make both cantilevered brake arms move in a mirrored synchronized manner. To resolve this I was thinking of installing a single cable both cantilevered brake arms to form the upside down "V" and then connect the upside down "V" to the main brake cable with a cable connecter.


This is a fairly typical conversion on old brakes. It can work if done right. The problem is getting the angle right. Suggest you take a look at Sheldon Browns site for starters:

http://www.sheldonbrown.com/brakes/index.html

And read through the Barnett manuals, found at the top of this forum. It might be a simple as having the wrong size straddle wire.

http://harriscyclery.net/site/page.cfm?PageID=49&Category=450

Also check that the bosses ( the frame anchors ) have the pins in the same hole (there are 3).
Both SHOULD be in the same position.
Pull the brakes apart ( grease them ) check that both
internal pin anchors for the springs are in the same hole,
Shimano has 2 internal pin positions.

legalize_it got it probably, I set them up as close as I can then adjust the screw.

Good luck!

Hi,
I found a straddle rod to be helpful. The knurled knob just underneath the yoke adjusts the legth of each rod seperately. Nice to eliminate some of the cable stretch
as well.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3664894730&category=27949

I have late 80's MTB with Shimano DX cantilever brakes in which the main brake cable connects to one of the brake arms and the other brake arm is connected to the main cable with a short cable (barrel end x compression clamp).

After many attempts and once by LBS I cannot seem to ever make both cantilevered brake arms move in a mirrored synchronized manner. To resolve this I was thinking of installing a single cable both cantilevered brake arms to form the upside down "V" and then connect the upside down "V" to the main brake cable with a cable connecter.

Now for my questions.... do you recommend doing this? Or am I just not setting up the existing system properly?

The brake cable moves freely within the little housing there is. I hope you were able to follow my description.

PS Yesterday was the first time I was able to ride outdoors since I broke my collar bone 6 weeks ago (went down while riding in the rain). My shoulder is a little sore today but it was nice to get off the stationary cycle.

Lets take one issue at a time. The cable routing that you are referring to is called a "link wire." The important feature of this system is that, if the brake wire ever breaks, it will just pull out of the way. Older designs that used a straddle cable would catch on one of the tire tred knobs and put you over the handlebars. I think that you should keep the link wire system.

If your brake arms aren't working in a synchronized manner, most likely your problem is return spring tension. Each arm has it's own return spring and, if the tension on them isn't the same, only the arm with the stronger spring will return. Most Shimano cantys of that era have a little screw on one of the arms. Adjusting that screw inward or outward will adjust the tension on that spring. Usually if you fiddle with it enough you can get the two arms to balance.

If that doesn't work, look to where the arms mount on the fork or stay. Most canty mounting studs of that era had a series of three holes in them for the end of the canty spring to poke into. By using one of the alternate holes on one arm or the other, you can affect the balbnce of the springs.