Fast Talk 193: Buying Speed Episode

I enjoyed the recent podcast with Ben Delaney re: buying speed, but… there was one thing, maybe a little thing, regarding rolling resistance that is so often misquoted that it’s become almost gospel. Specifically, the idea that wider tires are faster than narrower tires of a similar construction or within the same model.

It’s true (-ish) IF you’re considering equal tire pressure for both sizes. Nobody does that, though. For example, look at the chart from, comparing the rolling resistance of 4 sizes of the Conti 5000. The rolling resistance for the 32mm tire is lower than for the 25mm tire at 80psi (9 watts vs 10 watts). No one would run a 32mm at that pressure. Drop the pressure for the 32mm down to 60psi (still a tad high for all but the heaviest riders) and the resistance jumps to 10.3 watts. Now you’re looking at an ever so slightly higher resistance for the wider tire under conditions you’d more likely see IRL.

Another wrinkle to throw into the equation: once the tire width exceeds the rim width, aerodynamics suffers greatly, as well. Unless you’re riding very wide rims and riding on relatively rough pavement, the science doesn’t support the conclusion that wider tires are faster.


Fast Talk Episode 95: Lennard Zinn & the Art of Tire Pressure

Note that the transcript is included for this episode.

I thought, after listening to @trevor mention the “easy to work on” type bike, that we could post a pic of the bike we train/race on.

I’ll start:
Ritchey Logic, steel frame, 8.8kg, 2015 frame.

It’s comfortable, and suits my needs. I enjoy every Km on it. I have a 2007 Schwinn with DA7800, and while 1Kg lighter, it’s not as comfortable.

Back to the Ritchey. Full 105 group set, and little to no carbon components (only cages and fork). Standard wheels are Fulcrum Racing 3, and I only use the Mavics for fast flat faces where speeds are >38km/h average over 100km.