M
Michael Press
Guest
In article <[email protected]>,
"(PeteCresswell)" <[email protected]> wrote:
> When I went from WTB Mutano Raptors (55/55) at 35 psi to 1.25" slicks at 90 psi,
> I think I picked up at least 2 mph average speed on my commute.
>
> Not really knowing anything, my guess is that most of that came from decreases
> in both "barn door" wind resistance and aerodyne effect (i.e. no lugs whipping
> the air).
>
> Guy on a road bike passed me today, but he was young, more aero, and working at
> it - while I was running just a little beyond cruise mode - i.e. not consciously
> trying, but somewhat beyond my normal aerobic pace enjoying a little bit on an
> endorphin rush.
>
> He got a hundred yards or so ahead and then the space between us remained
> constant for quite awhile after that.... So I'd say that a couple-two-three mph
> would have evened us up.
>
> Now I'm wondering if I'd get anything like that increase by going from the
> inch-and-a-quarter slicks to "real" road wheels - as in 700 or 29" or whatever
> the standard size is... and the skinniest tires that will let me ride without
> obsessing about the quality of the road surface. Since it has disc brakes, I'm
> pretty sure my frame would handle the diameter.
>
> Somewhere in the back of my mind my real agenda is the thought of starting to do
> group rides and being able to keep up with riders of similar ability (or lack
> thereof...) on road bikes.
>
> Anybody been there? Is this wistful thinking?
Inch and a quarter slicks at 90 psi are almost optimal.
Slightly narrower and higher pressure will give a
measurable decrease in rolling resistance, but will not
make you faster in the real world.
Do you remember the buzz that those knobby tires made on
the pavement? That is where the 2 mph was going.
--
Michael Press
"(PeteCresswell)" <[email protected]> wrote:
> When I went from WTB Mutano Raptors (55/55) at 35 psi to 1.25" slicks at 90 psi,
> I think I picked up at least 2 mph average speed on my commute.
>
> Not really knowing anything, my guess is that most of that came from decreases
> in both "barn door" wind resistance and aerodyne effect (i.e. no lugs whipping
> the air).
>
> Guy on a road bike passed me today, but he was young, more aero, and working at
> it - while I was running just a little beyond cruise mode - i.e. not consciously
> trying, but somewhat beyond my normal aerobic pace enjoying a little bit on an
> endorphin rush.
>
> He got a hundred yards or so ahead and then the space between us remained
> constant for quite awhile after that.... So I'd say that a couple-two-three mph
> would have evened us up.
>
> Now I'm wondering if I'd get anything like that increase by going from the
> inch-and-a-quarter slicks to "real" road wheels - as in 700 or 29" or whatever
> the standard size is... and the skinniest tires that will let me ride without
> obsessing about the quality of the road surface. Since it has disc brakes, I'm
> pretty sure my frame would handle the diameter.
>
> Somewhere in the back of my mind my real agenda is the thought of starting to do
> group rides and being able to keep up with riders of similar ability (or lack
> thereof...) on road bikes.
>
> Anybody been there? Is this wistful thinking?
Inch and a quarter slicks at 90 psi are almost optimal.
Slightly narrower and higher pressure will give a
measurable decrease in rolling resistance, but will not
make you faster in the real world.
Do you remember the buzz that those knobby tires made on
the pavement? That is where the 2 mph was going.
--
Michael Press