Thursday, September 18, 2014

Brakes compared - TRP CX9 and Tektro CR720

I went for a short 2-hour bike ride after work yesterday. Unfortunately, days are definitely getting shorter so 2 hours is max. I can ride for before it gets pitch black. I moved along Concord River from Billerica border to Concord, stopping by at the Greenough Pond.
There is a trail along the southern bank of the pond connecting with Maple St. That was supposed to be a nice shortcut, at least according to the map. What map didn't tell me was that the trail looked like this:
I have seen a lot of crazy trails in the woods around Boston but this one beats them all. No matter what bike you bring with you, good luck riding there. I wouldn't want to try it even on a fat bike. I ended up carrying my bike for more than a mile.

But I was supposed to write a bit about brakes. For the last 2 years, I have been using Tektro CR720 cantilever brakes on my Poprad. They were a big improvement over Avid Shorty 4 cantis that came with the bike. CR720s actually are able to stop this bike, something I couldn't say about Avids. These Tektro cantilevers are very nice brakes, especially when you consider that you can get them for $48. For a full set! A single brake pair weighs 144g (with hangers). In my opinion, CR720s provide sufficient stopping power for the money. Available in silver or black.
So why did I even consider replacing them in the first place? Two reasons, I could say. First, they are very wide, which isn't really an issue as long as you don't kick them with your shoe when mounting/dismounting or if they don't interfere with your panniers. The second reason is typical for all cantilever systems - they are really tricky to set up properly. Once you realize that you have to account for the right toe-in, pad angle, distance from rim, hanger cable angle, etc. you may just not want to deal with them at all. This is why I looked for something a bit different.
Tektro CR720 cantilever brakes:
+ cheap ($24 each)
+ quite powerful
- wide
- tricky to set up (typical for all cantis)

After searching through available options, I decided to bite the bullet and get what's supposedly one of the best brakes out there - TRP CX9. These are made by essentially the same company but are positioned in a different performance bracket. Maybe that's why they cost $144 for a full set. Oh, and of course, these are not cantilevers. Being mini v-brakes, they are much easier to install and set up. In fact, I didn't have to do much set up at all. Just align the pads a bit and they are good to go. A single brake weighs 146g (without adjustable noodles) so there isn't any weight savings in brakes, should you be concerned. But once you add the weight of cable hangers (back and front) you should be able to drop the weight of your bike just a little bit.
TRP CX9s are designed to work with road brake levers and they do indeed work very well. However, they have to be set up much, much closer to the rims than cantilever brakes. This is normally not an issue, as long as your wheels are perfectly true. Also, make sure your wheels are build well and strong so they don't deflect under load or you will hear constant pad rubbing. This is the main issue with mini v-brakes and probably the main reason why we don't see them on cyclocross bikes. I don't race in cyclocross so I'm perfectly happy with the new setup. The only other issue that I found with CX9s is very minor - edge finish. Edges of the brake arms are pretty sharp and should definitely be rounded a bit in machining. They just don't have a nice feel.
On the positive note, performance of CX9s is top notch. They are super powerful and locking the wheel has never been this effortless before, even with the stock pads. Speaking about pads - they have replaceable shoes that you can simply slide out and slip new ones in. No need to remove the entire pads from the brakes.
Also, CX9s have 90mm long arms (hence the name), which leaves plenty of space for fenders.

As a final note, the tiny M3 arm tension screws at each brake boss require 3mm hex key, which means that I quickly replaced them with standard slotted screwdriver screws. This way I don't need to bother with even carrying a 3mm hex around as I don't have such screws anywhere else on my bicycle.

TRP CX9 mini v-brakes:
+ super powerful
+ easy to adjust
+ adjustable noodles
+ plenty of space for a fender
- requires pads being placed very close to rims
- sharp edges of brake arms
- a bit pricy

1 comment:

  1. I've ridden 3-4 bikes that were equipped with CR720 brakes, and despite endless tinkering, I could never get the brakes to work to my liking. I tried different levers, straddle cable heights, and pad compounds. None of those things made an appreciable difference. After replacing the CR720s with $15 BMX mini-v brakes, I swore off cantilevers for good.