Radius Cantilever Adjustment Problems

Erik Voldengen said:

I've seen this type of canti brake work very well with great rim-pad clearance as well. But I
can't seem to get it right on my own bike. Has anyone used these brakes with success? How high did
you put the yoke? I'm using these with Shimano STI levers. I can't seem to get good braking power
or pad clearance. Any tips would be greatly appreciated.

Bikes vary somewhat in spacing between the canti bosses, as well as rim width and boss-rim height
difference. If your bike has canti bosses that are close together, high profile cantilevers will
always point down (cable anchor at or below boss). If this happens, lowering the straddle cable will
not increase mechanical advantage. The cure is really to switch to a medium profile canti. I have a
bike with high profile cantis (Diacompe 983) and they just could not be set up well on the front, so
I had to switch the front. The rear works ok though because the bosses are farther apart.

"Erik Voldengen" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

I recently bought a pair of radius cantis for my cross bike. I'm having trouble finding the "sweet
spot" for the staddle wire carrier position.

I've looked at Sheldon Brown's canti geometry page which was helpful, but the angles are way
different on these brakes and are more like the "wide profile" design that he dismisses as
obsolete and inferior to low/medium profile cantis.

I've seen this type of canti brake work very well with great rim-pad clearance as well. But I
can't seem to get it right on my own bike. Has anyone used these brakes with success? How high did
you put the yoke? I'm using these with Shimano STI levers. I can't seem to get good braking power
or pad clearance. Any tips would be greatly appreciated.

Thanks, Erik

I have a friend with the Spooky brakes. Looks like he runs the straddle cable about an inch higher
than the bottom of the HS.

Try that.

Mike

Quoted message said:

Erik Voldengen said:

I've seen this type of canti brake work very well with great rim-pad clearance as well. But I
can't seem to get it right on my own bike. Has anyone used these brakes with success? How high did
you put the yoke? I'm using these with Shimano STI levers. I can't seem to get good braking power
or pad clearance. Any tips would be greatly appreciated.

Benjamin Weiner said:

Bikes vary somewhat in spacing between the canti bosses, as well as rim width and boss-rim
height difference. If your bike has canti bosses that are close together, high profile
cantilevers will always point down (cable anchor at or below boss). If this happens, lowering
the straddle cable will not increase mechanical advantage. The cure is really to switch to a
medium profile canti. I have a bike with high profile cantis (Diacompe 983) and they just could
not be set up well on the front, so I had to switch the front. The rear works ok though because
the bosses are farther apart.

Moving the pads in from the arms is a variable often overlooked. Set them such that the brake shoe
post is not past the pivot bolt when it hits the rim.

If you try that with unlubricated shoe holders, the shoe posts will slip which is yet another reason
to lube every fastener.

Then set the transverse to a ninety-degree angle ( again, with the pads on the rim). Our culture
produces lots af gauges. Grab any paper and hold the corner in your field of view between you and
the wire. Lastly ( or simultaneously for a Link Wire setup) bring up the main cable tension .

After you've ridden it you can decide whether it needs to be either firmer-feeling or more
effective. Lower or raise the carrier accordingly. Sheldon addresses this very well.

I don't recall a case of having to actually change the style of brake to get a positve nice-braking
setup with any cantilever.

My only beef with the Radius brake is that if you set it up at all well you cannot disensgage the
transverse wire for a wheel change without tools. You might add another adjuster inline and leave
them both up a bit.

As with any brake work, if you don't do this sort of thing regularly, give the levers a good hard
pull with all your might before getting on the bike.

--
Andrew Muzi www.yellowjersey.org Open every day since 1 April, 1971

Erik Voldengen at [email hidden] wrote on 10/28/03 12:19 AM:

Quoted message said:

I recently bought a pair of radius cantis for my cross bike. I'm having trouble finding the "sweet
spot" for the staddle wire carrier position.

I've looked at Sheldon Brown's canti geometry page which was helpful, but the angles are way
different on these brakes and are more like the "wide profile" design that he dismisses as
obsolete and inferior to low/medium profile cantis.

I've seen this type of canti brake work very well with great rim-pad clearance as well. But I
can't seem to get it right on my own bike. Has anyone used these brakes with success? How high did
you put the yoke? I'm using these with Shimano STI levers. I can't seem to get good braking power
or pad clearance. Any tips would be greatly appreciated.

The stock pads with the Radii brakes are pretty mediocre. They get a little better as they wear,
but they don't inspire confidence. I picked up a set of the KoolStop dual compounds from Sheldon's
site, which make a noticeable difference. You can also modify the pad clearance by changing the
washer stack.

I got them to work well by setting the cable straddle holder at about an inche above the tire top.
This on Michelins which are about 35mm (measured).

I use 'em with STI brake levers

Sheldon's reference is always excellent (which I realize you'd visited):

sheldonbrown.comcantilever adjustment.htmlOpen ↗

KB has a canti set-up "rant" here:

bontrager.comrants.aspOpen ↗

Hope that helps,

-- Jim

Quoted message said:

I got them to work well by setting the cable straddle holder at about an inche above the tire top.
This on Michelins which are about 35mm (measured).

Thanks for the tips. I'm not exactly sure what a "tire stop" is. Do you mean the top of the tire?

-Erik

Quoted message said:

Moving the pads in from the arms is a variable often overlooked. Set them such that the brake shoe
post is not past the pivot bolt when it hits the rim.

Thanks very much for the information, but I'm not sure what you're saying here. These brakes use
v-brake style pads, so I don't see how I'd possibly achieve what I think you're suggesting. It is
quite possible I just don't understand what you mean here, so could you perhaps clarify?

You are saying to extend the pads as far away from the brake arms as possible, right?

Erik Voldengen at [email hidden] wrote on 11/1/03 10:41 PM:

Quoted message said:

Quoted message said:

I got them to work well by setting the cable straddle holder at about an inche above the tire
top. This on Michelins which are about 35mm (measured).

Thanks for the tips. I'm not exactly sure what a "tire stop" is. Do you mean the top of the tire?

yep - about one inch above the top of the tire.

-- Jim

Erik Voldengen at [email hidden] wrote on 11/1/03 10:48 PM:

Quoted message said:

Quoted message said:

Moving the pads in from the arms is a variable often overlooked. Set them such that the brake
shoe post is not past the pivot bolt when it hits the rim.

Thanks very much for the information, but I'm not sure what you're saying here. These brakes use
v-brake style pads, so I don't see how I'd possibly achieve what I think you're suggesting. It is
quite possible I just don't understand what you mean here, so could you perhaps clarify?

Kool Stop pads give you a set of washers that you can shuffle to change distance from the rim.

Erik Voldengen said:

Quoted message said:

Moving the pads in from the arms is a variable often overlooked. Set them such that the brake shoe
post is not past the pivot bolt when it hits the rim.

Thanks very much for the information, but I'm not sure what you're saying here. These brakes use
v-brake style pads, so I don't see how I'd possibly achieve what I think you're suggesting. It is
quite possible I just don't understand what you mean here, so could you perhaps clarify?

You are saying to extend the pads as far away from the brake arms as possible, right?

Not always, but somtimes it is a big help. You would want to avoid a setup where the brake shoe
mount is past the pivot when it hits the rim.

VBrakes commonly use a nutted brake shoe holder. Those are supplied with various spacers which can
be placed between the arm and pad or on the outside of the arm.

The variables here are the brake stud position (how far apart they are) and then the rim width.
IIRC, this started with a description of a brake setup where the posts were far apart and the
symptoms led me to think the pads should be moved in a bit.

I just worked on a bike a few days ago where the relatively new pads didn't touch the rim when the
arms themselves caught the nubs on the edge of the tire! Clearly the wide brake stud position, a
skinny rim and a fat tire combined to require pads farther from the arm.

--
Andrew Muzi www.yellowjersey.org Open every day since 1 April, 1971