Originally Posted by
bbbean
Check your assumptions. How do you know what the OP has or hasn't done? For all we know, the OP is getting ready to attempt the hour record and has done all those things.
On GP 5000 tires? Really?
If he was "ready to attempt the hour record", he just would have used a new tube instead of asking about it here.
From the tires, we already know he
hasn't "done all those things".
Originally Posted by
bbbean
FWIW, I was pondering this very question on my ride this morning and conducted a thought experiment. If we were to assume that we had a perfectly round wheel, tube, and tire on a perfectly smooth surface, we would expect rolling resistance to be very low, right? Now assume we introduce some irregularity to the situation - say a 2mm tall strip laid across the track every 2.1 meters. We would expect a small but measurable increase in rolling resistance, right? Now assume that instead of the irregularity being on the track, it was on the tire. Again, we'd expect a small but measurable increase in rolling resistance over the perfectly smooth tire.
The patch is on the tube. The tube is inside a much thicker casing, which means the patch thickness is pushed towards the center of the wheel. So, compared to your ideal-world example, "we'd expect" the rolling resistance of the patch to be much less. Maybe, on the order of variances of the casing thickness. It's "conceivable" that a patch, in the right place, could
reduce rolling resistance.
Originally Posted by
bbbean
Fortunately we have the technology available to measure the difference and to consider the relevance. In a sport where results are measured in tiny fractions of a second, the question is well worth considering, even if the likely answer is "don't worry about it."
It's highly unlikely that anybody would go through the expense of the kind of experiments necessary to detect the tiny difference in rolling resistance of a patch.
Originally Posted by
bbbean
Kudos to the OP and to folks like Chung and Poertner who consider topics like this and push the envelope of what is possible.
The mistake you keep making is ignoring that the OP was looking for a practical answer. On GP 5000 tires, he's not "pushing the envelope". You are just wandering off into the weeds taking about what's "theoretical" or "conceivable", avoiding answering the question the OP was really asking.