Sometimes while riding my bike over a familiar course with little traffic, I occupy my mind on problem solving. One question I have been thinking about as a possible optimal tire pressure trade off.
Observation #1, pedaling over a rough surface is harder than a smooth surface, noticeable for even slight surface roughness.
Observation #2, pedaling with hard tires are easier than pedaling with soft tires.
The physics behind #1 (presumably) is that energy is consumed by the bike riding up over the surface irregularities that does not get recovered coming down the other side. #2, energy is consumed by the sidewall of the tire flexing as the wheel moved forward and back. The more pressure the less side wall flexing.
Question: At what point does the pressurized air inside the tire tube act like a spring to absorb and return small amplitude up/down from surface roughness.
The tire contact patch is larger than the individual surface irregularities, so there is already an averaging process going on.
My suspicion is that tire pressure wall flexing dominates the energy usage more than surface roughness, but it would be cute to find a tradeoff pressure level between the two mechanisms.
or something completely different.
JR
Observation #1, pedaling over a rough surface is harder than a smooth surface, noticeable for even slight surface roughness.
Observation #2, pedaling with hard tires are easier than pedaling with soft tires.
The physics behind #1 (presumably) is that energy is consumed by the bike riding up over the surface irregularities that does not get recovered coming down the other side. #2, energy is consumed by the sidewall of the tire flexing as the wheel moved forward and back. The more pressure the less side wall flexing.
Question: At what point does the pressurized air inside the tire tube act like a spring to absorb and return small amplitude up/down from surface roughness.
The tire contact patch is larger than the individual surface irregularities, so there is already an averaging process going on.
My suspicion is that tire pressure wall flexing dominates the energy usage more than surface roughness, but it would be cute to find a tradeoff pressure level between the two mechanisms.
or something completely different.
JR