Meaty, Beaty Part Two...
 

I rode in to work today on the new 26x1.85 WTB "Slick" tires. As expected, they were smooth and comfortable even at their 65psi max; and grippy, especially cornering, as they have a rounded shoulder, smoother tread and are more supple than the 26x1.65 tires they replaced.

The "Slicks" felt like they had a slight increase in rolling resistance over the previous tires, and in fact, on three stretches of my commute my speed was down slightly 18mph vs 20mph and 21mph vs 24mph.

But I was in for a big surprise when I arrived at work. My average speed was consistent with the previous tires at 13.5 mph, and the ride time was consistent for this route on this bike with the previous tires, 38 minutes.

I had recalibrated the bike computer with the new tires, measuring the circumference by rolling the bike on the pavement and measuring, and the distance displayed at the end of the ride was within .05 miles over 8.6 miles as confirmed by three different bikes (and GPS).

The tires are WTB Slick 1.85's which I bought on clearance at Performance Bike for $13 each. They only have graphics on one side of the tire, and although they proclaim they are "flat resistant" and include a picture of a machine screw on the sidewall, I believe in this case "flat resistant" merely means they hold air. I do have my Mr. Tuffy tire liners in there as has been my practice for a few years now.

I wonder if the "Wanted Poster" of a machine screw on one sidewall is enough to actually ward off machine screws, and would it also be a deterrent to nails, thorns, broken glass and my apparent incompetence at mounting tires correctly.

At only $13 each, and considering this bike is no longer my #1 commuter, I am very happy with these tires for their comfort and cornering grip. But if this were my only bike for commuting (which it was for 15 years) I would trade some comfort for lower rolling resistance, plus more speed and robustness (Which is what I had in the previous tires).

Sounds nice, but I would consider dropping that psi considerably. I don't know how much you weigh, but I'm about 250, on about ~30-35lb bike+gear with 700x50 (29x2) marathon supremes, and I've settled on optimal pressure of 30 rear, 25 front. I can go even lower without (much) risk of pinch flat (tested every time I roll over the triangular bar on which my work's automated gate rolls), but I start to get whirring vibrations from the tires when cornering, which I believe to be the tires wrinkling under side load.

If you're a podcast kinda guy, this is a great listen.

I weigh 193. That bike is 21st least 32lbs and my back pack is around 25lbs depending on the season. I ran my suomi/Nokia studded snow tiress at 55psi on dry pavement, 35psi on ice and 15-25psi on snow but would have some dry stretches and for those 35 was too low with lots of extra effort and excessive bounce. 25psi and lower were horrible on dry pavement, but provided great stability and grip on the snow.

I am a podcast guy and will listen to your suggestion on this afternoons ride home....thanks! (one ear, curbside).

[QUOTE=BobbyG;19519514
The "Slicks" felt like they had a slight increase in rolling resistance over the previous tires...[/QUOTE]

Could that be since they are brand spanking new? I might be my imagination, but I suspect rolling resistance with slicks improves after a couple hundred miles...

Anyway, I'm a fan of bigger tires, run 1.95s on the two bikes I ride the most...

THanks for the suggestion! It's an interview with Jan Heine from Bicycle Quarterly! I had read his research on tire width on his blog, "Off The Beaten Path"

But this was even better as it also touched on other research that builds on his. Plus I had never heard him speak before. It made for a nice ride home (although I still have 20 minutes to go on the podcast.

The first 6 miles of my uphill ride home my average speed was 14.1mph which is 3mph over my normal speed. But I can't credit the tires; I had a 15mph tail wind. As soon as I turned east I lost the boost and my speed dropped back down to where I expected. But for a while there I felt like superman!

After listening to the podcast I may experiment with dropping the tire pressure.

I'm glad you liked it. I think my favorite part might be the train analogy, you might not have gotten there quite yet, I think it's near the end.

I've thought a little about a pressure-dropping experiment. I need to choose a good stretch of road, I think I want like half a mile of moderate downhill. Fix a posture (hands in the hoods, lock the elbows) and coast down. Not sure if I should try to start with the same number of pedal strokes each time, or roll across a start line at a certain speed. Have my pump (with gauge) strapped to my rack, or hidden in the bushes at the start, repeat at increments of 5psi, from 60 down to 10.

I've never heard this theory. I doubt it, but what do I know.

All Hiney is saying is what offroad cyclists have known forever. Overinflated tires are slow and will beat you to death. Buy quality tires. Next.