Hi everyone, I've got another newbie question for you.
I'm getting along fine with my bike maintenance and building skills. I now build wheels. I can assemble all the main components on a bike. I built a fixie this month.
However, I have a 1991 Trek mountain bike with Koolstop salmon pads and the Shimano Alivio cantilever brakes are miserable. I can spend an hour trying to toe in the brakes properly using rubber bands on the leading edge and a clamp to properly position the brakes. Last time I did this, I got a dozen miles off-road without squealing. I have to toe it in a lot to keep it from squealing. Hung up the bike, commuted 200-300 miles on my singlespeed, it broke, I rode the mountain bike around for couple days while I repaired it.
SQUEAL SQUEAL SQUEAL even though no change in the position or tightness of the brakes occured.
What gives? It's literally been fourteen years I've had this problem. Constant brake adjustment. I follow the books and I'm almost at the point of wasting money replacing the entire brake system with newer V-brakes. It appears to me that the brakes are torsionally flexible (1991 Shimano Alivio) and therefore even a decent toe-in will be rotated into a reverse toe-in.
However, I have a 1991 Trek mountain bike with Koolstop salmon pads and the Shimano Alivio cantilever brakes are miserable.
Quoted message said:
SQUEAL SQUEAL SQUEAL even though no change in the position or tightness of the brakes occured.
Any thoughts?
I didn't notice where/if you indicated the age of the /pads,/ but I'll give you an easy one to /try/:
1) File down the pads with a mill file in case they've gotten glazed with age;
2) Take a Scotch-brite (or equivalent) scrubby pad and high-test isopropyl alcohol to the rims' braking surfaces.
Can't be sure that'll fix your problems if what you really have is that much flex in the brake arms, but it can't hurt. The arms (or the bosses) on the canti's on my mtb seem to flex, too, but I don't have the squealing problem with my Kool-stops.
However, I have a 1991 Trek mountain bike with Koolstop salmon pads and the Shimano Alivio cantilever brakes are miserable.
Quoted message said:
SQUEAL SQUEAL SQUEAL even though no change in the position or tightness of the brakes occured.
Any thoughts?
I didn't notice where/if you indicated the age of the /pads,/ but I'll give you an easy one to /try/:
1) File down the pads with a mill file in case they've gotten glazed with age;
2) Take a Scotch-brite (or equivalent) scrubby pad and high-test isopropyl alcohol to the rims' braking surfaces.
Can't be sure that'll fix your problems if what you really have is that much flex in the brake arms, but it can't hurt. The arms (or the bosses) on the canti's on my mtb seem to flex, too, but I don't have the squealing problem with my Kool-stops.
I was going to suggest not eating spicy foods before riding.
{pause}
Oh wait. That's for recurring /nightmares/ not brake squeal.
On Sat, 15 Jan 2005 04:06:42 GMT, Collin <[email hidden]> may have
Quoted message said:
Any thoughts?
You'll get lots of suggestions, and any of them may be worth trying. I had one canti-equipped bike whose brake squeal went away when I pulled the canti arms off and greased the pivots. This is one of the things that comes onder the heading of "might work, doesn't cost anything but a little time, and can't hurt." It also may have no effect, but then, it sounds like you've been trying some of the regular measures already...so this might be worth a shot.
-- My email address is antispammed; pull WEEDS if replying via e-mail. Typoes are not a bug, they're a feature. Words processed in a facility that contains nuts.
However, I have a 1991 Trek mountain bike with Koolstop salmon pads and the Shimano Alivio cantilever brakes are miserable.
Quoted message said:
SQUEAL SQUEAL SQUEAL even though no change in the position or tightness of the brakes occured.
Any thoughts?
I didn't notice where/if you indicated the age of the /pads,/ but I'll give you an easy one to /try/:
1) File down the pads with a mill file in case they've gotten glazed with age;
Moderately new pads - PLENTY of rubber left on them. I've filed them twice, in addition to scoring the rims with heavy grit sandpaper and wiping everything down to ensure I don't get a quartz crystal embedded in the pad.
Quoted message said:
2) Take a Scotch-brite (or equivalent) scrubby pad and high-test isopropyl alcohol to the rims' braking surfaces.
Haven't tried alcohol. This sounds like a better way to ensure everything's super clean. I'll give it a try.
Quoted message said:
Can't be sure that'll fix your problems if what you really have is that much flex in the brake arms, but it can't hurt. The arms (or the bosses) on the canti's on my mtb seem to flex, too, but I don't have the squealing problem with my Kool-stops.
On Sat, 15 Jan 2005 04:06:42 GMT, Collin <[email hidden]> may have
Quoted message said:
Any thoughts?
You'll get lots of suggestions, and any of them may be worth trying. I had one canti-equipped bike whose brake squeal went away when I pulled the canti arms off and greased the pivots. This is one of the things that comes onder the heading of "might work, doesn't cost anything but a little time, and can't hurt." It also may have no effect, but then, it sounds like you've been trying some of the regular measures already...so this might be worth a shot.
I've done this at least twice over its lifetime, primarily because when it gets too dirty only one pad engages, then the friction causes the other pad to roll over and engage. It actualy helped the squeal temporarily! Oh well. Thanks! -Collin
If the grease on the pivots stops the squeak then the squeak was from clearance in the pivot bushings. The grease effectively pads the surfaces to reduce the chatter. I had a set that the bushings got excessive and that didnt even help. When there is clearance in the pivots they can also allow the pad to effectively rotate in relation to the rim, thus negating the toe-in. To check for this, clamp the brake (with the lever) and push the bike back and forth. If there is a visible ammount of end-play on the arms (1/16-1/8) then you probbably have too much clearance.
