Personally, I would use the Bonty aero TT lite (or whatever it's called.) with Latex tubes. Bring one (or more) of the sealer reflators, some patches, etc. DO NOT hit the rumble strips. They are chasms and will eat tires. They're several feet wide, about 10-12 inches across and 4-5 inches deep. If you are headed for one, do a bunny hop. I wonder if someone specified the size in cm and the contractor used inches.??????

Any comments on this one??

2) Regarding Crr that has been calculated on rollers, do the differentials between tires in magnitude and ranking tend to hold up over ground as environmental conditions i.e. surface, wind, temperature are variable? Is it possible that a higher Crr on a roller may actually be higher ranked (lower Crr) on the road as compound/profile is more amenable to "real world" conditions?

Cheers!

Regarding Crr that has been calculated on rollers, do the differentials between tires in magnitude and ranking tend to hold up over ground

Not only do the differentials between tires "hold up", they do so with such precision that you can use the data to diagnose equipment problems (in this case, the outlier shown as a red square was found to be the result of bad bearings due to a missing spacer in a Zipp disk):

do these "lab" measure or bench testing hold up when the tires are run on the road

Thanks Tom,

I think what you are describing speaks to "reliability" and “sensitivity to change” of the testing on rollers. I am not questioning that as in such a controlled environment with calibrated system I would expect as much. Validity, however, is what I would like to know about, meaning do these "lab" measure or bench testing hold up when the tires are run on the road where the variables are different and certainly harder to control.

Cheers!

Thanks Tom,

I think what you are describing speaks to "reliability" and “sensitivity to change” of the testing on rollers. I am not questioning that as in such a controlled environment with calibrated system I would expect as much. Validity, however, is what I would like to know about, meaning do these "lab" measure or bench testing hold up when the tires are run on the road where the variables are different and certainly harder to control.

Cheers!

Anyone else using PR3's????? I thought that was the tire of choice here. Thats what Ill be using.

Thanks for posting that graph, doc! Based on this information, if I were to do a couple of 20 min efforts on my rollers with different tube/tire setups at the same (fairly easy-to-attain) wattage, I should be able to graph out the average watts vs. average speed, correct? I'd love to be able to reliably do an at-home test on good flat-resistant tires...

I love my Veloflex Corsas as race tires - I get them from this guy http://cgi.ebay.com/...?hash=item2c5192f780. 700cX20 clinchers... Are they flat resistant - not overly so - I flatted on my last ride, but had several hundred flat free miles prior to this event. But seriously, goat heads go through just about anything, so if you're overly concerned about flatting put in some of those tire liner things... Or do those make you slow???





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