Gears & Gadgets: Disc Brake Alignment Tool
By David Cohen, Maryland National Capital Park Police Reserve Unit
Like many of us, I enjoy perusing social media apps like Facebook. These apps, though, have a spooky way of incorporating advertising as if they were reading your mind. With cycling being one of my pursuits, I get a fair amount of bicycle ads.
I had noticed that the rear brake on my 29er mountain bike had lost its effectiveness. I had just installed new pads during the bike’s winter overhaul, so the probable cause was that the pads got contaminated, or that the rotor had picked up some grime, reducing the brake’s effectiveness. I was not looking forward to pulling out the pads to clean them. This is because although on the Tektro brakes, the pads are fairly easy to remove by removing the brake caliper, lining the caliper back up again after putting everything back together has always been a pain.
As I contemplated this repair, an ad popped up for a “Cycle Bud Disc Brake Adjusting Tool”. The ad made it look as simple as this: loosen the caliper, insert the tool, tighten the caliper, and you’re on your way. It cost $19.95 for a pair of alignment tools. While I did not think much about how Facebook could possess such clairvoyance, for $19.95, I figured, “What the heck?” Of course, as soon as I purchased the Cycle Bud tool, my Facebook feed completely lit up with every other company that sells a similar tool.
I received the tool a couple of days later. The disc brake alignment tool is basically a pair of oval metal shims joined together by a clip. It is very small - about 2¼ inches long by ¾ inch wide at its widest point; small and light enough to be part of a rider’s on-bike tool kit. It even has a hole if you want to put it on a key ring.
Using the tool is every bit as simple as it appeared in the video: loosen the caliper, feed the tool into the caliper, tighten up the caliper bolts, and you’re ready to ride. If, for some reason, the tool won’t fit between the pads, it may be necessary to spread the pads. There are specific tools for this (such as the Park Tool PP-1.2 or PS-1), but if you’re out in the field, using your multi-tool will work. The one caveat for using the alignment tool is that the disc rotor needs to be straight. A disc rotor that is warped, bent, or otherwise out of true is going to rub, no matter what you do with the alignment tool. For those situations, you would need a rotor truing fork, like the Park Tool DT-2. I covered this topic in a previous Gears & Gadgets column, The Most Annoying Sound, Part 1, which can be found on the IPMBA website: https://ipmba.org/blog/comments/gears-and-gadgets-the-most-annoying-sound-part-1-disc-brakes.
After using the tool on my hydraulic disc brake-equipped personal bike, I next tried it on my department-issued bike, a Kona Dew, which has mechanical disc brakes. The brakes on my Kona have a history of being fussy in terms of rubbing or being noisy when applied. The only way to avoid the rubbing and/or the noise was to back the pads off so there is a longer pull to engage the brakes. I like to set my brakes very tight, so a long throw is uncomfortable for me. I had to back off the brake pads to get the alignment tool to fit. However, once the pads were backed off, the tool worked every bit as easily as it did on the hydraulic brake equipped bike. Once the pads are aligned, you can tighten up the pads to your liking.
Besides being easy to implement, the results were simply amazing. On the hydraulic brake equipped 29er, I’ve had issues with noisy brakes and poor engagement of the rear brake, specifically. No more. The brakes are quiet and engage well. My very fussy mechanical disc front brake on my department-issued Kona has never worked better. I was able to set my front brake tighter than I was able to do previously. It stops well and there is no brake squeal.
Surprisingly, Park Tool, which I would consider the gold standard for bicycle tools, does not offer a tool like the Cycle Bud alignment tool. However, these tools are plentiful on the internet. Among other names, they are sometimes called “Brake Fitting Assistant” or “Disc Brake Gap Regulator”. Prices range from about $15 to $20; money very well spent, in my opinion. Once you have one of these tools, you will wonder how you ever lived without it. I sure do!
Gears & Gadgets is a blog written by David Cohen #1116. It features various repair tips and tricks that David has picked up in nearly 25 years of cycling, including 12 years of public safety cycling. Gears & Gadgets will also periodically review some of the latest “gadget” items of potential interest to public safety cyclists. The advice and opinions in this column are solely the author’s and should not be interpreted as IPMBA mandates or recommendations unless explicitly stated.
About the author: David Cohen is a 12-year volunteer with the Maryland-National Capital Park Police. When he isn’t riding or tinkering with bicycles, David can be found tinkering with vintage cars or World War II airplanes. An avid historian, David enjoys researching and writing as well. He can be reached at onyxsax@aol.com.
(c) 2022 IPMBA. This article also appeared in the 2022 Conference Highlights issue of IPMBA News.