Are narrower tires really more efficient?

[Tom Sherman]

[email protected] aka Frank Krygowski wrote:
> On Oct 14, 9:05 am, Tom Sherman <[email protected]> wrote:
>> [email protected] aka Frank Krygowski wrote:
>>
>>
>>>> Tire were 47-406 Mitsuboshi Tioga Comp Pools.
>>> Hmm. I wonder if there were any significant differences between your
>>> bike and mine (and the OP's). What do you think?
>> Most likely.
>>
>>> FWIW, not only are my tires narrower than yours, they're also way
>>> larger in diameter.
>> butbutbut, you did not specify that in you post. A better statement
>> would have been, "I'd never try a century on 38 mm tires, on a bicycle
>> with wheel sizes ranging from ISO 571-mm to ISO 630-mm".
>
> Sorry, your logic is wrong.
>
> My statement is correct as it stands. A smaller wheel diameter would
> not tempt me to violate what I said.

I did a metric century with a 28-406 Conti GP rear tire, because it came
on the bike. The harsh ride and poor handling on loose surfaces
convinced me to change the tire for a 47-406 Tioga Comp Pool, which was
an all around improvement (and likely lower rolling resistance to boot).

--
Tom Sherman - Holstein-Friesland Bovinia
Beer - It's not just for breakfast anymore!

 

[David L. Johnson]

Tom "Johnny Sunset" Sherman wrote:
>
> Huh? I road a double-metric century in about 6-1/2 hours on 47-mm wide
> tires, and my best century time was on 44-mm wide tires.
>
This does not change the fact that, with narrower tires, which
would-be/could-be/must-be inflated to a higher pressure, the rolling
resistance would be lower. So, had you gone down to 23mm tires, you
might have been able to do that double metric in 6 hours.

But if you want to ride with fatter tires, fine. No harm, and you do
get somewhat more exercise per mile.

--

David L. Johnson

A mathematician is a machine for turning coffee into theorems.
-- Paul Erdos

 

[Tom Sherman]

David L. Johnson wrote:
> Tom "Johnny Sunset" Sherman wrote:
>>
>> Huh? I road a double-metric century in about 6-1/2 hours on 47-mm wide
>> tires, and my best century time was on 44-mm wide tires.
>>
> This does not change the fact that, with narrower tires, which
> would-be/could-be/must-be inflated to a higher pressure, the rolling
> resistance would be lower. So, had you gone down to 23mm tires, you
> might have been able to do that double metric in 6 hours.

And I would have been bouncing all over the place on the bumps. Not to
mention the better traction of the wider, lower pressure slick on the
damp, high speed descent, or that I could have wedged a narrower tire
into the longitudinal gaps on the bridge I crossed at high speed. Or
pinch-flatted when I hit a pothole. Narrow tires have no place on a
faired recumbent ridden on poor to fair condition roads.

> But if you want to ride with fatter tires, fine. No harm, and you do
> get somewhat more exercise per mile.

Well, there are no ISO 406-mm tires narrower than 28-mm. I doubt that
any of them have a lower rolling resistance on typical roads than the
47-406 Comp Pool (based on rolling resistance tests).

--
Tom Sherman - Holstein-Friesland Bovinia
Beer - It's not just for breakfast anymore!