Modifying Kool Stop Brake Pads

Updating vintage brakes with modern pads and cables is a great and easy way to improve their performance. Modern cables often have less friction, which can lighten the "feel" of an old pair of brakes, and modern brake pad compounds are quite a bit better than what was available "back in the day." If you have vintage brakes and are still using vintage pads, those pads may not have been anything great to begin with, and by now they are probably so hard and dry that it's a wonder they can stop a bike at all.

I've found the brake shoes from Kool Stop to be a good choice for improving older brakes - they come in a couple of different compounds (black, or salmon), have some adjustability for toe-in, are fairly inexpensive, and will work with a lot of different vintage brakes. One issue with them, however, is that they are made to be uni-directional, with a long "tail" that sometimes interferes with the forks on older bikes. In some cases, the tail of the pads gets caught up on the forks with the result that the brakes won't open up wide enough to get the wheel out. Kool Stop does make a version they call "Continental" pads which are shorter and simply rectangular - but they also don't have the toe-in adjustability, which in my view is a strike against them.

The good thing is that the longer pads can be easily modified - and here I'll show you how.

I just installed these new Kool Stop Eagle Claw Salmon shoes on this set of vintage Dia Compe center pulls. You can see that the tail of the pads extends back into the fork. In this instance, the spacing is actually not too bad and the brakes will probably open up wide enough despite the pad/fork interference - but I'm going to trim them anyhow.

 One thing you need to know about the Kool Stop brake shoes is that they are molded around a steel "foot" that runs most of the length of the shoe - stopping just short of the tail end of the pad. If you cut the shoe, you want to make sure you clear the metal foot.

Looking at the braking surface of the shoe, you can see there are two "rain grooves" that divide the pad into 3 sections. The metal "foot" that is inside the shoe ends just about where the second rain groove is at the tail end of the pad. That little ¼ in. section at the tail is the part we're going to cut off. You could probably use a basic utility knife for this, but I personally prefer a straight razor blade (nice, new, and sharp) for the job.

The blue lines show the approximate location of the metal foot. I suggest cutting on a bit of an angle through the tail end of the rain groove and outward - to make sure you don't run into the foot. If you do hit and expose it, it's not the end of the world (once on the bike, it's doubtful anyone would notice) but I'm anal retentive enough that it would drive me nuts.

Cuts like butter.

The cut is smooth and straight. When on the bike, the cut will disappear. 

It's usually only necessary to do this to the front pads - as the rear brakes often have a little more space between the seat-stays - and the brakes are usually oriented so that the long tail of the pads points away from the stays to the rear of the bike.

On the bike, you can't tell the shoe was cut, but it has increased the clearance. The next thing is the mounting posts. On the threaded versions of these shoes, the post is really long. It's possible they make it long so it works with more models of brakes - but I can't imagine any brake that needs the posts to be as long as these are. No problem. After the brakes are set up, with the position and angle you want, it's easy to cut off the end of the post with a Dremel tool. I do it with the pads mounted in the brakes, and use a file or a small abrasive wheel (also mounted in the Dremel tool) to smooth the end. If you cut the post prior to mounting, you might find it hard to get the nut started on the threads after cutting.

That's all for now. More updates on the bike projects will be coming soon.