capnjonny 

When I do an overhaul on a bike that the bike exchange wants to sell I do the following ( on cantilever brakes) .
remove the brake arms and clean and grease the posts
Sand the brake shoes on my belt sander removing all glazing
clean and sand the rim s with 400 grit sand paper with a palm sander
clean off the rims with alcohol.
Adjust the brakes so the pads have good contact with the rims.

Doing all this , sometimes , while the braking is improved, I still can't get the bike to skid when applying the brakes.
Admittedly, I am 260 lbs. and that might have something to do with it but some bikes just stop better than others.

What, if anything can I do to improve things?

dsbrantjr

1) If the pads are old and hard they will still be old and hard after sanding.
2) Ditch link wires where installed and install straddle cables with the carrier kept as low as practical.
3) Don't double-post

FastJake

Don't sand the rims. You're just wearing them out faster. Cleaning them is enough.

+1 to new pads if needed. Kool Stop salmon work best.

I didn't see anything about replacing cables and housing in your post. That can make a big difference if you're fighting internal friction or poor cable routing and setup.

alcjphil

There is a reference to attending to the cables in the OP's other thread

mrrabbit 

Pretty much agree with everyone else...

replace the pads
clean the rims, no sanding needed in most cases.
check the cable, housing and straddles

I am a fan of cleaning posts on all type of dual post brakes - oftentimes you'll find factory overspray still present. Doesn't hurt...

When overhauling bikes, don't go overboard dude. Learn to stick to the basics, you'll still do quality work AND save some time.

Sanding hardened pads and the rims are two examples.

The overly detailed stuff time wise is much better spent on wheel truing, dishing and tensioning, dialing in shifting and that those things directly related to safety are in place or not compromised.

For example, are you keeping an eye out for Shimano recall cranks?

=8-|

trailangel

andrewclaus

Almost every cantilever brake I see at the non-profit where I volunteer has badly adjusted straddle cables.

near and far

I agree, use the salmon/black Koolstops with mini Vbrakes on my gravel/everyday bike. They are just great. And a huge improvement over the unes that came with the Tektro Mini Vs (which really harmed the rims, too)

capnjonny 

Thanks for all the reply's folks. At the Bike exchange we are told to always sand or otherwise rough up the brake pads and clean the rims. While I have the tires off (to replace) I sand the rims with a vibrator sander that lives under my work bench. It takes all of about one minute per wheel . Then I wipe the rim with alcohol to remove any remaining rubber dust and contaminants. If the brake shoes are old and hard I replace them. Often they are like new with almost zero wear. I take them over to the belt sander and rough them up removing any ridges that may have developed. I also grind an angle into them so they sit flat on the rim. Only takes a minute.

On just about every bike I replace the cables and covers.

These bikes are destined for sale and at the bike exchange we try to make sure that they are in like new mechanical condition before we sell them. From a professional mechanics perspective what I do might seem like overkill but I am not charging for my time and I enjoy the work and I think the results speak for themselves.

Drew Eckhardt 

1. Insure your straddle cable isn't too long which reduces its mechanical advantage.
2. Upgrade to better brake pads. Kool Stop Salmon work well.