Tire and rim size data points.

Wayne Pein said:

An Avocet Fasgrip SL 700 x 25 mounted on a 2006 Campy Zonda wheel
measures a stout 26.1 mm wide at 100 psi. The rim is 21 mm outside
width, and 15 mm inner channel width. This inner width is pretty wide.
For comparison, a MA2 measures 13.5mm, an Open 4 is 13.2mm, and a more
modern Open Pro 14.5mm.

For comparison, you may want to see what the measurement of that same
Avocet Fasgrip SL 700x25 tire would be on the MA2/Open 4/or Open Pro?

I've used both the older Japanese-made black/tan sidewall Avocet
Fasgrip Road 30, listed as 700x28 (incorrect) and the newer Korean-made
all black Avocet Fasgrip SL 700x25 and the tires do vary from 24-26mm
wide on Open Pro rims.

Wayne Pein said:

measures a stout 26.1 mm wide at 100 psi. The rim is 21 mm outside
width, and 15 mm inner channel width. This inner width is pretty wide.
For comparison, a MA2 measures 13.5mm, an Open 4 is 13.2mm, and a more

I assume a "standard" 23mm tyre on such a wide wim would make a road
contact surface wider, and tyre profile lower - closer to D rather
than a V shape - than usual

Assuming you could run 25 or 28 mm tyres at the same pressure you
normally use for 23, would that make the road contact surface less
wide, and tyre profile sharper (ou higher)?

jbr

BigBen said:

Wayne Pein said:

measures a stout 26.1 mm wide at 100 psi. The rim is 21 mm outside
width, and 15 mm inner channel width. This inner width is pretty wide.
For comparison, a MA2 measures 13.5mm, an Open 4 is 13.2mm, and a more

I assume a "standard" 23mm tyre on such a wide wim would make a road
contact surface wider, and tyre profile lower - closer to D rather
than a V shape - than usual

Assuming you could run 25 or 28 mm tyres at the same pressure you
normally use for 23, would that make the road contact surface less
wide, and tyre profile sharper (ou higher)?

jbr

I think rim width effects inflated tire width to a small degree, but the
effect on contact patch would be even smaller.

Wayne