Tandem Cycling - disc brake break in

I test rode a new C'dale recently. I commented on what lousy stopping power the brakes had.I was told that all disc brake pads have to be broken in and that it takes many miles of braking to do that. Is this true?
It's tough to think about how great the braking in the future will be when you are headed for a crash because you cant stop.
Somebody please give me the word on this. Thanks

I was told that all disc brake pads have to be broken in

True... However, you can expedite the break-in process by searching out hilly routes and using the brakes on the descents instead of blasting downhill sans brakes. Initial break-in also causes what appears to be rapid brake pad wear. However, once the pads are bedded-in with the rotors the pad wear normalizes. When it's time to replace the pads you will go back thorugh another break-in period, but it doesn't take as long since the rotors are already seasoned.

It's tough to think about how great the braking in the future will be when you are headed for a crash because you cant stop.

OK; how about the opposite situation where you have the utmost confidence in your rim brakes and then it starts to rain and you find you have no brakes. It's an extreme example; however, it makes the point that brakes and tandems involve making some trade-offs and also require an understanding of how you'll use your tandem and how much brake power it will need under expected conditions.

I have a '08 Cannondale 2 with disc brakes. The break-in period was only one evening ride. So it is nothing, I have not replaced the pads, but the rotors are different looking now, I was told that there was a coating on them from the manufacturing process that needed to be removed during the break-in period. I have discs on my commuter bike too and they both can stop on level roads very fast. All most too fast on my single...

OK; how about the opposite situation where you have the upmost confidence in your rim brakes and then it starts to rain and you find you have no brakes. It's an extreme example; however, it makes the point that brakes and tandems involve making some trade-offs and an understanding of how you'll use your tandem and how much brake power it will need and under what conditions.

35 years ago when I had sprained or broken something, and was down to one (arm/hand/wrist?) I bought a set of the best brake pads money could buy. With those pads, my rim brakes worked about as well as my tires in the rain. (Could someone do something about that thin film of oil that rises to the surface at the first rain?) Those were Scott-Mathausers, and I'll be putting Kool-Stop Salmon pads on my tandem. http://www.sheldonbrown.com/harris/brakeshoes.html (available elsewhere too).

I have a '08 Cannondale 2 with disc brakes. The break-in period was only one evening ride. So it is nothing, ....

When we change pads or the rear disc, I set them one notch too tight. The wheel would turn "almost" freely. After a 10 mile spin the pads are set and if we need to stop we get some stopping power from the rear disc.

With a dual disc rig, one could alternate the replacement of pads between front and back...

Yeah well, be careful. In my experience not even S-M or Kool-Stop Salmon work right away in a "damn, I wish I wasn't out on the road right now" kind of rain.

As others have said, it needn't take "many miles" if you consciously use the brakes more than needed in your first ride or two. Our new-in-June Periscope triple has discs front and rear. The break-in period was just that -- a ride or two. Braking power is now confidence-inspiring. (Though our team+bike weight is only ~390 lbs, so YMMV.)

The break-in period was just that -- a ride or two.

Let me throw some additional chum in the water here....

In my past experience breaking in Avid disc brakes I've noted what I believe are at least two distinct break-in periods.

1. The first is the most basic where the rotor and pads become seasoned and go from having less stopping power than new rim brakes to being on par with the better rim brakes and pads.

2. The second occurs when the pads finally wear off enough brake pad material such that the entire facing surface of each brake pad conforms to the rotor's position as it moves between the pads, remembering the Avid's use a 'single piston' with a fixed inboard pad.


The latter means the outboard pad is pressed up against the rotor which, in turn, is then pushed up against the fixed inboard pad before any significant brake energy is developed. This slight off-camber orientation of the rotor will eventually be easy to see when you look at your brake pads as the inboard pad will be worn more at the top and the outboard pad more at the bottom.

Anyway, the point is, it has been my experience that you will not experience the full braking power of an Avid disc until that slightly off-camber ]/[wear pattern had been created on the pads... and the full braking power of the Avids is quite impressive even on just a rear tandem wheel application. For me, it was an eye-opening experience when the pads finally wore-in to the rotor.

Note: Having a dual piston brake caliper that moves both the inboard and outboard brake pads up against the rotor is pretty critical when you use rigid rotors like those found on heavier go-carts, motorcycles, and cars. They also make a lot of sense on the downhill grade, hydraulic disc brakes like our 4-pot Hope Enduro's. However, when your rotor is as thin as the one's used on lightweight XC and road bicycles, any initial advantage / braking power over a single piston brake goes away once the pads wear-in to the rotor. Therefore, IMHO either design -- single piston or dual -- is as good as the other so long as they are both properly adjusted and broken-in.

Wow. What a great first post experience for a newbie! And what an education I got.Thank so much to all of you.
~Alex

35 years ago when I had sprained or broken something, and was down to one (arm/hand/wrist?) I bought a set of the best brake pads money could buy. With those pads, my rim brakes worked about as well as my tires in the rain. (Could someone do something about that thin film of oil that rises to the surface at the first rain?) Those were Scott-Mathausers, and I'll be putting Kool-Stop Salmon pads on my tandem. http://www.sheldonbrown.com/harris/brakeshoes.html (available elsewhere too).

Had Kool-Stops on the tandem, and have them on my commuter road bike.

Swapped to Swiss Stops on the tandem and holy smokes those things work awesome!!! Much better than the Kool-Stops.

I just put a set on my weekend (nicer) road bike, to try out. The commuter will get the Swiss Stops once the Kool-Stops are worn out.

Cartridge style: http://cyclocrossworld.stores.yahoo.net/swrxghpgrbrp.html
Standard canti style: http://cyclocrossworld.stores.yahoo.net/swratgrcabrp.html

I used to work for the local Cannondale dealer, back in '99 Cannondale's mountain bike team mechanic stopped into the shop one afternoon on his way to a race in Colorado [talk about schwag :)]. He gave us all kinds of tips for tuning headshoks and disc brakes. At the time the team mechanics were breaking in discs by squirting a dirt/water mixture from a water bottle onto the rotors as they rode around the "infield". Initially, I thought this was crazy but gave it a try and amazingly it works pretty well. We would do this for our higher end customers, and I've still do it on my new tandem.

The other thing I have found is cleaning ANY oil of the rotor with Isopropyl alcohol. I have seen oily figure prints cause the brake not to work for a while.

Matt

If the rotors had been handled or weren't cleaned before you braked, you might never get the stopping power. Whenever I install new rotors, I always clean them and never touch then on the surface with my hands. The oils will get into the pads and you'll loose stopping power or have none at all. When I was a newbie, I learned this the hard way. And I'm alway amazed how oily the rotors come right out of the package from the factory. I also clean my rotors after every ride. So much oils and silicones on the road. I've never had any problem with discs since. I would suggest cleaning them and possibly changing out your pads. They might be contaminated and will never stop you properly.
Good luck.

There is really no difference between these and disc brakes for cars really. Sure they should be clean, but if they are properly bedded in - it won't make that much difference. If it a rear brake - find a downhill and do several soft applications to seat the pads in the caliper. Then do several hard applications coming to an almost complete stop. This will bed the pads in. As Tandemgeek said - after a short while the pad will contour better to the disc and stopping power will increase. If you glaze the pads right up front - by not properly bedding them in - you'll always have compromised brakes.