Our Toronto dealer Blacksmith Cycle has published a long-term review by customer Seetoh Lang on his Great Divide Disc, and especially his experience with road disc brakes. We've posted an excerpt from that review below along with some of the post's great images. Be sure to check out Blacksmith's blog for the full review.
"When deciding on a new road bike a year ago, I was nervous about the idea of potentially switching brake systems. I’ve happily ridden thousands of miles on caliper rim brakes, and they’ve been tried and tested by riders for decades. But my experience with disc brakes on mountain bikes got me curious - how would the all-weather prowess of a hydraulic disc brake system translate on a road bike?
My curiosity got the better of me, and I got delivery on a No. 22 Great Divide Disc a few months ago. I’ve since ridden 4,000 km on it in various conditions - from group rides in tropical downpours, to solo descents in desert heat, to hating the weather in winter ice and snow. [Note: now Seetoh lives in Austria, so add the Dolomites to that list]
This is what my experience with disc brakes on a road bike has been so far.
THE DECISION:
First, there were the choices of which standards to go with. There were quite a few of them.
Wheel mount:
Quick Release / 12mm thru-axle / 15mm thru-axle
Brake caliper mount:
Flat mount / Post mount
Disc mount:
Centrelock / Bolt On
Rotor size:
140mm / 160mm
Cabling:
Hydraulic / Mechanical / Hybrid
Since disc brakes are relatively new in road biking, this is all a leap of faith. The industry hasn’t had enough time to settle on reliable standards yet, so my choice was based on weighing calculated risks.
Eventually, I went with the following: 12mm thru-axle, flat mount, 140mm, centrelock, and hydraulic.
Build-wise, this translated to Shimano ST-RS685 brakes and Shimano SM-RT99 Ice Tech Centrelock rotors, mounted to White Industries CLD hubs on No. 22’s Great Divide Disc 12mm thru-axle system.
THE RIDE:
In good weather, these disc brakes have noticeably more power than my previous caliper brakes do, but it’s not out-of-this world different. As for modulation, these discs are definitely an upgrade, providing finer control of speed. The whole system is definitely an upgrade over rim brakes when the sun’s out, but not enough that I’d go screaming to the hills about it. Probably the biggest difference is being able to brake later into corners, which is an advantage in descents.
In rain, grit, mud, ice or sleet however, conditions that previously had me begging for my rim brakes to bite just don’t bother me anymore. They are incredible - the different between rim brakes and disc brakes in bad weather is absolutely significant. Bad weather has little effect on the modulation or stopping power of disc brakes.
Out on the road, this means I think less about braking. For example, if it’s raining on a descent, I don’t have to start braking earlier to clear water off my rim brake track, and I never wonder when my brake pads are going to bite. These brakes give me modulation or pure stopping power consistently everywhere, all the time.
As for the specifics, disc rub is quite rare on this system, which I am thankful for. They only squeal in very grimey conditions when the pads and rotors are in need of cleaning. When there is rub, the fix is usually really easy. I am relieved about this, as noise was one of my biggest trepidations when taking the leap. I did warp a disc from leaving the disc on the wheel when traveling, and have since learnt to take the discs off before the wheels go in a bike bag, which is very easy to do with centrelock."
Head on over to Blacksmith Cycle for the complete review.