Finally the day arrived when work schedule, weather, road conditions and newly installed metal pads all aligned. As I climbed, I was cautiously optimistic since I had installed the pads the night before and did a driveway test before this 4500 ft vertical descent. I leaned the bike against the snow plow and glanced over at the thermometer on the ranger shack which read 50F, within a couple degrees of the previous four rides. I rolled out of Glen Cove with the goal of repeating the experiment the same as the previous two runs with the thermal imager. As I entered the 3rd switchback the brakes were still quiet and smooth. I continued to descend. expecting the next switchback to heat the brakes and start howling but all was good. The metal brakes have a less smooth sound than fiber but were performing well. I double checked on Strava later in the day to verify the same descent time of about 9 minutes. As I stopped at the picnic area, I quickly dismounted and pulled the imager out of the Camelbak just like before. I pointed it at the rear and was shocked as it was 261F, or about 100 degrees hotter than I measured on the fiber pads. The run was fairly balanced thermally as the front fins measured 250F. I couldn’t believe the difference not only in the temperature but more importantly in the actual performance. It seemed the metal pads were doing a better job of conducting the heat of friction away from the rotor and brake pad keeping them quiet and smooth. I expected some improvement but not 100F hotter on the fins.
After five weeks and 22,000 vertical feet of descending since the first disheartening ride of the Pike Peak Highway, I finally had it dialed in.
Road Disc 
Very interesting. You are probably pushing disc technology far more than 99.9999 percent of consumers out there. I do have a question however – Have you done any test comparing a descent time between your rim brake bike and disc brake bike? I’d be interested to know the performance advantages in real terms.
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Actually I am not trying to push the technology as I have nothing to gain. I am just trying to get it out there that there are some caveats. I had 6 weeks of angst where I seriously questioned the purchase including possibly returning the bike, found little knowledge about road disc brakes even at the factory store where I purchased it, and have yet to descend from the summit (another 3000 ft). As mentioned you can’t even buy the metal pads in the US and this is 5 weeks after I started looking. Ultimately I am not sure road discs are the answer for all unless you tend towards the mountains and occasional precipitation as rims offers a lot of surface area to diffuse the heat compared to a 140mm rotor and inch square pad. I would hold off unless you have a pressing need or if you do buy make sure your LBS can back you if you decide you want metal pads.
As to your question I have not compared times and it is especially difficult as the road conditions vary especially this time of year with snow melt running across the road and occasional gravel dragged on the road from vehicles. I also don’t want to race downhill as descending the peak is typically more survival than a time trial especially in the high winds above tree line.
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