Quote:
Originally Posted by saab2000
It’s interesting that the resistance increases as pressure decreases. This is contrary to what we’re always told, making me thing their testing drum should be updated to more realistically simulate real conditions. Or else we’re not always being told the truth...  |
It's been known for a long time that the rolling losses internal to the tire itself increases with decreasing pressure. What has come into better appreciation in recent years is that vibrational losses
external to the tire (some times called 'suspension losses' or 'impedance losses') decrease with decreasing pressure. Josh Poertner at Silca wrote up a series of blog posts about this:
https://silca.cc/blogs/journal/part-...previous-works
The BicycleRollngResistance.com tests measure the internal tire losses (Poertner refers to this as the 'casing losses'), so their data will show a decrease in resistance with increasing pressure. Other testing has shown that tires with lower casing losses also have lower suspension losses, so the BicycleRollingResistance should still be reliable for indicating the relative differences in total rolling resistance between tires, even for real world conditions.