What's Wrong With These Cantis

[Hindmost]

Above are good suggestions for adjusting and balancing the canties. The rim still doesn't appear centered in the fork? Install the wheel flipped around and see where the rim sits. This should tell you whether you might have a wheel or fork issue.

[kbone]

Also adjusted the toe-in and straddle cable. Messed with the spring tensioners too. Lessened the shudder, but didn't resolve the core issue.

Took Hindmost's suggestion to flip the wheel again (image below). It looks more centered when flipped. Also provides more clearance on the quick release side of the cantis. What does this mean in terms of a "fork problem"?

[harlond]

Maybe it's the picture but the wheel appears to be closer to the non-drive side fork blade than to the drive-side blade.

[GScot]

Just to add to your variables, I had bad results with the brake pads on Tektro 720s with regard to shudder. Switched to Kool Stop thinline and after adjustment I was happy with brake performance. Put them on two bikes at the same time. One has never required more than maintenance, the other one can't decide which way to go on the front. After one ride the left pad will start dragging and after adjustment by the end of the next ride the right will be dragging. I've tried half adjusting but 20 to 30 miles and one pad will always be dragging. I'll probably solve the problem with some Pauls at some point.

[ultraman6970]

IMO the adjustments using the screws at the canti arms should be enough even if the fork has a problem.

If the wheel was checked at the LBS then i will say it is right at the middle spot, then the next one imo is that you have a problem in the drop outs, maybe one is longer than the other one?

If the bike doesnt pull anywhere while riding even no hands then the fork and the frame are straight, but that doesnt mean one of the drop outs is a mm off. Maybe paint is under one drop out and thats why the wheel is off center??

Seen chromed fork with this problem.

Remove the drop out and check if the axle fits flush in the drop out (both sides), if not then you found the problem.

[Hindmost]

Originally Posted by kbone

...What does this mean in terms of a "fork problem"?...

From 3000 miles away, it sounds like your rim is slightly off center and you could have a "fork problem". Both could be very minor but somewhat irritating. As ultra mentioned a "fork problem" can mean something a little wonky in the way the axle engages the dropout.

The wheel flip test in general tells you: When the wheel is properly dished and the rim stays in the same location but off center--it's a fork problem; When the the fork is straight and the rim moves from side to side--the wheel dish is off.

[fogrider]

https://www.amazon.com/Tektro-Front-.../dp/B006GHDS5A

I have given up on canti brakes! the shudder comes from the flex of the fork with the long exposed cable. the above hanger lessens the exposed cable, so less shudder.

for the same price of the hanger, I would (and did) go with mini Vs.
https://www.jensonusa.com/Tektro-926...RoCj74QAvD_BwE

[pdonk]

If the cantilever springs are different colors- one silver one gold they may have been inadvertently swapped. Try switching them to the other arm. May even out tension.

I know Paul's and old shimanos use this system to differentiate left from right.

[pinkshogun]

if the fork legs/wheel are straight, one of the drop outs could need a filing to get the rim centered between the legs

[Gummee]

IME if toe in doesn't fix it, try toe out. IOW the back of the pad hits 1st.

There have been a few 'problem children' over the years that had that problem.

...but... I'd say 'mini-V' before those cantis all day, every day. The mini-V removes some/most of the flex from the system so reduces chatter. Mini-Vs also actually stop you. Bout the only down side to v-brakes is mud clearance.

M

[thwart]

Originally Posted by fogrider

https://www.amazon.com/Tektro-Front-.../dp/B006GHDS5A

I have given up on canti brakes! the shudder comes from the flex of the fork with the long exposed cable. the above hanger lessens the exposed cable, so less shudder.

Good point. On this bike, you are lucky enough to have a front brake hole to mount this, and it will help.

The V-brake vs canti brake debate rages on...

[notsew]

Originally Posted by fogrider

https://www.amazon.com/Tektro-Front-.../dp/B006GHDS5A

I have given up on canti brakes! the shudder comes from the flex of the fork with the long exposed cable. the above hanger lessens the exposed cable, so less shudder.

for the same price of the hanger, I would (and did) go with mini Vs.
https://www.jensonusa.com/Tektro-926...RoCj74QAvD_BwE

Agree, your underlying problems is that the brakes are canti-"they work great when you set them up correctly"-lever. Mini-Vs 4 life

[jc031699]

One of your pads (right) is installed at a substantial angle to the brake arm which is holding it, compared to the left one. It’s visible from the front view pics. This is in the direction perpendicular to what you would set for toe in. That seems to be the main difference between the two sides.

If it’s tight either way you can get more clearance by using v brake shoes with thinline pads. Some CR720’s were sold with those so it works.

Also, as others said squealing should be adjusted with toe in.

If you are getting shuddering on the front, you may need a fork mounted cable hanger instead of stem or steerer mounted. Tektro has those.


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