Bicycle Brake Adjustment

Yes, I know--an exciting post about installing replacement cantilever brakes on my beater commuter bike. The operation involved far too many trips to the bike store, but was ultimately successful. Hopefully, it will be useful to some reader, sometime--and save them some trips.

After riding my Dahon Jack folding bike around for a bit, I realized, "Man... the brakes on my normal commuter bike are really crappy in comparison." I figured it was high time to tune up the brakes on the vehicle I use for 80% of my commuting. So, first trip to the bike store:

1. Bought a new set of pads--I figured the old ones were worn.

Then, I started reading Sheldon Brown's article on adjusting cantilever brakes. A wealth of information there--but what was really informative was the section on centering the brakes. For most of the time I have ridden bikes, it always seemed like one brake shoe would end up closer to (or even dragging on) the rim. So in order to make the brakes not drag, I'd have to adjust the brakes "open" enough that it really diminished braking power.

It turns out that you ought to be able to adjust the spring, so that the two brakes pull evenly, with the wheel centered between them. Went to check out my front brakes, which definitely had the problem described above.


Multiple adjustment holes: nope. Adjustment screw: nope. Huh. Turns out that I have old-and-cheap brakes:

Non-adjustable springs are found in older or cheaper cantilevers. If these need adjustment, you must physically deform them. You can sometimes increase the tension of the spring by unhooking the transverse cable and forcing the cantilever out much farther than it would normally go. If that doesn't work, you may need to slide the shoe in or out of the eyebolt to adjust clearance.

So off to more trips to bike stores:

2. Bike store A: "You should be able to adjust the springs." "I checked, I can't." "There should be an adjustment screw." "No, it's not there." "There should be a few holes you can choose from." "Nope." "Try cleaning off and regreasing the brake pivots, to even out the friction." Already did that. Can I get a replacement spring, to try it out?" "You can, but it won't make a difference." [Leaves]


3. Bike store B: "Can you sell me a new spring?" "Um, sure... don't think it will work though. $1 from the spare parts bin. You should probably just buy new brakes."
   
   Tried it out--no dice. Another trip to the store.


4. Bike store B: "New brakes? And returning the unused brake pads and spring?" "You got it. With those returns... $5.25."
   
   Started the installation... looked pretty good; the new brakes have that adjustment screw. But then I realized I was changing from a straddle cable/yoke to a link wire. Which requires a new brake cable. Arrrgh!


5. "New brake cable? And a crimp anti-fray cap?" "You got it... $4.19"

Finished off the install... front and rear. Both brakes nicely centered. Stops on a dime; no brake squealing (that's a toe-in adjustment). Yay!



You can see the adjustment screw (the one sticking out the side of the cantilever body, upper photo), which changes the spring tension. Man... it's embarrassing that I've been tinkering with bikes for so many years, and I only figured out that adjustment now.

Hey--no wisecracks making analogies to my social life! Not nice.