Planet X CNC Ultralight Brakes

I've been riding Planet X brakes for a year now and felt it was time to write about my experiences with this product. It has mostly been very positive, but there are a few things about the brakes that might make some folks think twice about them.

The first thing I noticed about the brakes when they arrived was how nice looking they are. The finish is much better than I expected and after a year of all-weather riding, they have held up extremely well.

The next thing I noticed is just how light the brakes are. These have a claimed weight of 205 and came in a touch lighter than that at 197g on my scale. When you start to examine the brakes you can pretty easily see where some of the weight is cut. The adjusters are a mix of plastic and very cheap feeling aluminum. There is a visible spring on both brakes that does not look quite as stout as what I am used to from Campy brakes, but still seems to be fairly solid in construction.

My brakes shipped with SwissStop black pads which have been solid performers for me. The brakes also ship with a small wrench for holding the cable barrel in place, an extra barrel, and I believe an extra grub bolt or two. Unfortunately, the directions were not that good and and installation (specifically the initial adjustment) was more difficult than it should have been.

Installation is similar to pretty much any other dual pivot brake out there. Simply insert the main securing bolt into the fork or frame and tighten the bolt. I don't recall any specific torque settings being provided with the instructions. One key point is to make sure the brakes are as centered as possible before you begin attaching the cables.

This is where the installation is quite a bit different than other brakes. The cable runs through a standard type barrel adjuster attached to one arm and down through an aluminum barrel that has a hole drilled through it. The cable goes through the hole and there is a small grub bolt that presses the cable against the inside wall of the barrel to hold the cable in place. When I first saw this design, I thought it would be absolutely horrible and slip. Sure enough, it did the first time I tried to tighten the bolt down. Then I realized that the small wrench is used to hold the barrel in place which allows a lot more torque to be placed on the bolt. Once I mastered this little move, the cables have stayed secured with zero slipping.

Once the cables are attached the brakes can be centered by using the small hex bolt on the front of the brakes. The brakes are adjustable from 35-50mm which is plenty for the wheels I run which include 24mm wide Hed wheels with 25 mm tires down to 19mm race wheels with 21 mm tires. If you tried to run super wide tires you may run into problems but they would have to be well over 30 mm tires IMO. There are two adjustments for opening and closing the calipers, the first is the traditional barrel adjuster that the cable runs through. Turn it clockwise and the calipers open, counter clockwise closes them. There is also a cool little grub bolt on the arm of each caliper where the cable attaches that presses on the spring. This will also allow you to open and close the calipers (same directions to open and close).

The brake pads are easily adjustable up and down via a bolt on the side of the pads. The pads are Shimano compatible which is kind of odd when you really think about it. There is no lever on the brakes to open and close them like you would find on Shimano or Sram brakes so they would ideally be run with Campy levers, but they went with Shimano pads. I actually prefer the Shimano pad design as I think that even though you have to loosen a bolt to change the pads, they come out much easier than Campy pads. Also, most bike shops have a bigger selection of Shimano pads as well. To clarify my statement, these brakes will work with Shimano/Sram levers, the caliper release just does not exist so you may have to loosen them using the barrel adjustment which would take a few seconds longer.

The brakes are absolutely fantastic on the road. They provide more than enough stopping power for my giant carcass and they have a really nice feel. The brake modulation is excellent for me. I have read several people say that the forged version of the brakes are stiffer, and I guess I could see that, but with the stopping power more than adequate, I'm not sure I would want to give up any of the feel that I have with the CNC version of the brakes. I would need to ride the forged version to be sure.

So what are my dislikes? The big one has to do with the barrel adjuster interface with the brake cable. It could just be me, but they seem a hair small. I run Gore Ride On Professional cables and the ends fit in easily enough, however when I try to adjust the brakes it turns the cables with the adjusters. It has gotten so I just grab a pair of pliers when tuning the brakes this way. I have tried to make some Jagwire ends work, but that has not helped. I even tried a little lube, but that still did not fix the problem. Another hit for some users would be that there is not a mechanism for quickly opening and closing the brakes to change tires. With Campy this is not an issue and in most cases you could probably run the brakes a couple of mm more open and be fine, but for some users this might be a problem.

Those issues aside I would highly recommend these brakes to any racer or recreational cyclist. They work well, seem to be reliable and have extremely high value relative to pretty much any other brakeset on the market.