The Psychology of Speed

I replaced the tires on my Trek with some 700x40c tires last week and the results have been kind of surprising. Typically I’ve run tires in the 35-37 range, but in preparation for my tentative plans to ride the Midnight Century this year I wanted to try something a little beefier. I actually found some knobby 700x45c Panaracer Fire Cross tires online that could have potentially converted the Trek from a hybrid to a virtual 29er, but the frame clearance would have been super tight and I didn’t feel comfortable shelling out $70-80 only to find out it wasn’t actually a workable tire for my fork and frame.

The 700x40c Kenda Kross tires I ended up getting instead were actually quite inexpensive. They essentially worked out to $10 each after shipping and they had a more practical tread pattern anyway- smooth down the middle with some beefy knobs on the edges. I didn’t expect them to be particularly fast, but they definitely looked like they would be a lot smoother rolling than an mtb knobby on the street surfaces I ride on most of the time. And as it turns out they’re plenty fast too.

Late Thursday night I finally put the new Kendas on, simultaneously removing my rear rack and both fenders (feeling optimistic despite all the crazy rain this summer). The Friday morning commute into work was my first test run. I couldn’t find my Trek’s bike computer since I hadn’t ridden it in about a month, so I decided to use my watch to time my route into work instead. I rode pretty steadily, but in no way felt like I was pushing the pace during the commute. In fact, based on how I was feeling and my experiences riding into work the last couple years I figured I was somewhere in my typical 25 km/h range on the straightaways (and faster going down the hill of course).

I didn’t bother to look at my watch until I rolled into work and was stunned to see a sub 18 minute number. I don’t think I’ve ever beaten 18 minutes for that route using my bike computer and it pauses the elapsed time whenever I come to a full stop. Friday I was operating strictly on running time and between 29th, Southeast Blvd and Trent I usually have to wait a little bit for cars to pass before I can cross and continue on my way. I don’t remember not having to wait for any cars at the usual problem intersections, but besides being in a riding zone cross traffic must have been extra favorable.

Somehow the new tires, excellent riding conditions, and all the daily riding I’ve done on the trainer and on the road his year has begun to translate into some speed improvements on the Trek. Friday I really didn’t feel like I was riding that fast on the straight aways, but it looks like the speed gains I’ve been seeing on my Univega road bike are trickling down to the Trek as well. And apparently my new fatter tires aren’t slowing things down much either. I’m not sure exactly how much of this is just in my head (as opposed to bike or physical improvements), but I’m happy to finally be getting my general cruising speed up towards 30km/h. That’s the somewhat arbitrary number I’ve been working toward for a few years now and with the bike computer running today I was able to further confirm the improvement. Now I really want to drop some weight and work on my climbing efficiency. I’ve come along ways, but there’s still lots of room for improvement.