Look at me talking when there’s science to be done.
This evening, I tried the Arthurs Seat loop on my mountain bike rather than my usual city bike. The mountain bike is much lighter, but the tyres have more rolling resistance. I was hoping that the weight reduction would see me fly up the hill fast enough to compensate for the drag0reduced top-speed. But I didn’t know whether the tradeoff would be worth it.
So, after powering up and down the hill, I was pleased to to see that I’d broken the twelve minute barrier for the first time – 11:44 for one lap. No idea what my heartrate was, because I’ve misplaced my monitor, boo. But twelve minutes is significant because it means that a “5 laps in one hour” target isn’t too far off.
But when I got home and looked at the GPX trail, I got a surprise. My climb been a whole minute *slower* than my previous ride. But the descent was 1m20s faster. Not sure what happened on the way up. The gearing is all different, and maybe without the HRM I wasn’t pushing as hard as I could’ve?
It’s not a huge surprise that the descent was faster. On the last ride I took the cycle path, whereas this time I had a clear run on the road. I also pushed 30mph the whole way, thanks to the big gears I have on the MTB. On the city bike, my nexus hub runs out of ratios and I have to freewheel part of the way. Either way, it looks like drag wasn’t a big deal. The Panaracer Razer tyres I have on the MTB are pretty quick too.
It’s not that long ago that this kind of analysis would’ve been the preserve of olympic athletes. I think it’s great that you can do it all yourself now with a low-end phone! You can even play ‘what if’: if you stitch together the climb I did last time with the descent I did tonight, you’d get a lap of 10m44s.
Now, where did that cake go?