Monday, January 7, 2019

Testing one, two: Amazed.

Holiday travel and dumping snow put a hitch in our tire comparisons for a bit.  Yet on the last few rides we've done the trails have been zipped up tight, courtesy of all those unlucky saps that found snowshoes under their yule log.

The only noteworthy observation I can share from these last few rides is that immediately after swapping bikes to compare float, speed, and overall feel of the 2 tires we're scrutinizing, Jeny was quick to observe, "I'm amazed how much faster your bike feels than mine".

To be clear to the point of redundancy, she's riding Johnny 5's on 105mm rims, I'm riding 2XL's on 105mm rims.  

I completely agreed with her statement -- my bike had considerably better glide on the fast-for-us surfaces.

When we got back to the trailhead we gauged all 4 tires to make sure nothing was really 'off' that would skew our perceptions.  Jeny's tires were both at 4.1 and mine both at 4.4 psi.

When you consider that I outweigh her by at least 65#, you might conclude that I should be running *less* pressure to achieve the same combo of speed and float.  And if our tires had exactly the same air volume that'd be correct.

But the 2XL's are bigger.  Only a few millimeters wider, but a *lot* taller.  My suspicion has always been that that added air volume matters a lot in how well I can float at these relatively high pressures. Our observations on this set of rides seem to confirm that.

Next step -- once the weather pattern settles a bit and we can count on consistent conditions for a few days in a row -- will be to get scientific with repeatable rolldown tests.


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