Tire width for slow uphill commute

[aboylikedave]

Which width tyre would you recommend for absolutely minimising the flat and uphill effort on a hilly commute? I'm not bothered about speed.

I changed from a 28 (BOntrager Racelite hardcase) to a 25 (Gator HArdshell) and found it took more effort despite being lighter. Changed the back to an old 32 Bontrager and it feels easier. Pressures were 100 for the 28 and 120 for the 25.

I'd always thought thinner = 'faster' = less effort. But is this perhaps not the case uphill at low speeds?

 

[dabac]

The main advantage of narrower tires is when aerodynamics start to make themselves known. Until then, other features will be more important.
Light tires, or rather low rotating weight, is important for rides featuring a lot of speed changes. At slow climbs, when each turn of the crank will bring a visible boost/coast phase this can be real important.
Soft sidewalls is a key feature.
With a rigid sidewall, the folds and deformation in the load affected zone will steal some energy all the time. I've been really happy with Hutchinson Top Slick from that perspective.

There's also the fact that with a narrower tire at higher pressure, every small bump you roll over will force the bike upwards. A wider tire at lower pressure will allow somethiing like a single piece of gravel to make an indentation instead, w/o hoisting the bike upwards.

 

[aboylikedave]

Thanks Dabac. What about momentum from a heavier tyre? Would this help the lazy rider?

 

[dabac]

Originally Posted by aboylikedave .

Thanks Dabac. What about momentum from a heavier tyre? Would this help the lazy rider?

Momentum, particularly for a human-powered vehicle is a mixed blessing. When you're at (even) speed, cranking away nicely, it doesn't matter much either way.
You'd have to plot the speed over time with a real high resolution graph before you'd be able to see the differences when your pedals are at the power stroke and when you're passing through dead center.
On a flat course a heavier but more aero wheel/bike is often a beneficial tradeoff.
But when speed begins to drop, and maybe you're even getting out of the saddle, losing cadence, then the powerstroke will eventually begin to be quite visible.
And due to the losses, primarily in rolling resistance, the momentum will never pay back as much as you put in. The slower you go, the less of it there is in the first place, so rolling losses become proportionally bigger.

Then there's us humans. We're really quite hopeless as measuring devices. We may do rather well in noticing differences, but comparing these differences to some absolute, quantified reference is near impossible. Whichgoes a long way towards explaining why people tend to be faster on a bike that feels faster. Something in the character of one bike(setup) just prompts us to try that little harder than we'd have done on another bike (setup).

Now, just don't ask me at which speed/cadence one takes precedence from the other!/img/vbsmilies/smilies/wink.gif