Self Energising Cantis

Cyclopath! - Keiron said:

Hi All,

Despite the range of extremely average to poor reviews i went ahead and
purchased the Suntour SE cantis anyway, just needed to see for self. Unlike
any other canti's i've seen these have no exposed coil/spring end which
slips in to the hole on the boss. How the hell then do i install these (got
no instructions)? Do i rely on the pressure/friction of the bolt and caliper
on the boss or what?

Yes.. It has been a while but you are substantually correct. IIRC there
is a hex shaped plate (for want of a better description on the bottom
that you can use to adjust them with a cone wrench.

I don't know why most of the reviews are the way they are.. it seems to
me that the complaints are more due to poor set-up and lack of
understanding of what they are about.
The only valid complaints there are with them are:

i) they are a bit of a PITA to set-up service
ii) they can make feathering your brakes more difficult (though you'll
get used to it)
iii) when mounted on the "flimsy" rear stays they don't work as well as
they should since they actually torque the bosses away from the rim ..
a 7$ brake booster fixes that.

Cyclopath! - Keiron said:

Hi All,

Despite the range of extremely average to poor reviews i went ahead and
purchased the Suntour SE cantis anyway, just needed to see for self. Unlike
any other canti's i've seen these have no exposed coil/spring end which
slips in to the hole on the boss. How the hell then do i install these (got
no instructions)? Do i rely on the pressure/friction of the bolt and caliper
on the boss or what?

Thanks

I started a thread here a lot like this a while ago:
http://tinyurl.com/s68ne .

I haven't worked on the Suntour version but I understand they're a
fairly direct copy of the Pedersen brakes I got quite familiar with. I
don't remember all the details now, but on those, the brake mounting
bolt does pretty much everything. It holds the spring tension/centering
adjustment in place and also holds the brake on to the post. On the
brakes I worked on, I was forced to use much care and willingness to
shoot in the dark in setting the bolts tight enough while avoiding
mushrooming the canti posts. Using threadlocker may not technically be
necessary with these, but it's probably a very good idea since it gives
you a bit of safety net to make up for trustworthy. The Pedersens also
had aggressively toothed washers to help avoid loosening of the bolts.
They're hokey but probably shouldn't be left out.

Also, I believe it's possible to set these up in a way that could
eventually make it impossible for the pads to contact the rim once the
pads have worn enough. Each brake arm's range of motion is quite
limited due to the design of the brakes (the threads on the threaded
bushing-like part inside will become fully engaged with the threads
they mate with and not allow the brake to rotate any further). I'm not
sure what this would be like when it happens in practice, but I'm
guessing it could equate to a pretty sudden failure of the brake in the
right situation. Just take a look at how this all works during setup
and you should be fine.