Roller Cams On The Brain

Roller cam brakes   (Image from a sale ad on social media)

Years ago when I started poking around on the internet, one of the rabbit holes I went down concerned flared drop bars for mountain bikes. If you decide to dive into that hole it won't take you long to find the name "Charlie Cunningham". 

Charlie was a tinkerer, a co-founder of WTB (Wilderness Trail Bikes), and had his own mountain bike frame building company with his name on the downtube. Amongst his many contributions to mountain biking, and cycling in general, Charlie developed a braking system which had better modulation and power than typical cantilever brakes of the 1980's. They had a look unlike anything else out there and were called "roller cam brakes" because they featured a triangular shaped "cam" and rollers, or little wheels, at the ends of the brake arms. 

When I saw that SunTour had licensed the design from Charlie, I started keeping an eye out for a bicycle with those brakes on it. In fact, I had one, (and still do) back in the 90's. It was a Mongoose All-Mountain Pro. It featured the "Cunningham Design" SunTour roller cam on the rear stays. Back in the 1990's, no one knew anything about these weird brakes, and so I was kind of left in the dark, besides some tantalizing tidbits I'd see from time to time in magazines, or in a WTB catalog of the day. 

So, I was fascinated with roller cam brakes from that time onward. I ended up with a bicycle that has them front and rear, (a Schwinn High Sierra), which will be featured soon here on the blog. But recently we had a "barn find" come into the Cedar Valley Bicycle Collective which had the brakes on it front and rear. What is more, this bike had the "proper" arrangement: The rear brake was under the chain stay, where it was intended to be. 

See, Charlie Cunningham thought that traditional cantilever boss design placement on the seat stay and lower on the front fork blades was inferior. This traditional placement allowed the stays and fork to bow outward under braking pressure, which represented a loss of braking efficiency. What is more, those typically spindly rear stays could also twist, further degrading braking performance. Charlie's design placed the bosses higher up on the fork blades, near the base of the Unicrown, which was a lot stronger and less prone to flexing outward. In the rear, Charlie advocated for a placement of the bosses to be on the chain stays, which were vastly stiffer and less prone to twisting than the rear seat stays were.Not every bicycle that used roller cam brakes on the rear put them on the chain stays though. Neither of my two examples have that placement.

The red arrow points to where the brake boss is on the chain stay

The roller cam brake idea caught traction, and in the years 1986, 87, and 88 roller cam brakes were a big deal on many mountain bikes with probably 1988 being the "high water mark" of the "under-the-chain stay brake" fad. 

However; riders revolted against these saying they were "mud-catchers". Many were decrying the difficulty in getting rear wheels off to repair flat tires, and their voices were heard. By 1989 rear and front cantilever brakes returned to their "proper places" on frames and the roller cam idea was relegated to WTB bikes, for the most part. They were never heard from again, especially when dual suspension bikes were developed and after 1996, when Shimano introduced the linear pull, "V" brake. WTB folded up production of roller cam brakes in the late 1990's. 

So, roller cam brakes are not often seen anymore since any bike you'd typically see these on is going to be rare, as MTB bikes weren't the big deal in the 1980's as they were in the 90's, and these examples are around 35 years old or so by now. So, when a Dorado branded bike slid into the Collective last week with these brakes, in a size I could ride, well, my brain went into hyper-drive about what I could do with it. 

I don't need this bike. However; I am so smitten by roller cam brakes that I cannot stop thinking about restoring this old, rare beast and turning it into a touring bike, or a gravel rig, or..... Who knows?! 

A little about this bike: It is a "Dorado" branded bike, which, as far as I can come up with, was a house branded MTB made for sale at Costco stores. But instead of being some cheapo, big-box type quality sled, they actually made these out of decent ChroMoly main triangles and slapped quality SunTour bits on them. I also gathered that in today's dollars, a bike like this cost about $700.00, so there probably are not too many "Dorado" bikes around anyway. 

The Bad: It needs paint. The bike sat in a barn for decades and it got pretty scratched up. The wheels need redone, and the cables, housings, and that sort of stuff is needing attention.

The Good: the roller cam brakes are intact, work, and the drive train is also intact with SunTour top mount friction shifters also intact. And....it would fit me like a glove. I took some basic measurement and not only is the saddle already at my optimum height, the top tube is perfect. It has a 9" long head tube, so I could even put drop bars on this.

What Will I do: Don't know yet..... Stay tuned, but I may just salvage the brakes and bits and keep them for spares for my two other roller cam bikes. OR- I may build this up and replace my current 'townie'. Again- I don't need another bike! 

Note: Charlie Cunningham is still alive and has fallen on some difficult times in terms of health. If you are so led, here is a link to a fundraiser to help with his medical bills and recovery costs.