Tire height question

[elviento]

Got some 33mm Schwalbe Rocket Ron for my CX rig and the knobs come very close to the chain stays. Tire height measures 35mm from edge of the rim to the tallest point. Since the edge of the rim is more or less 7mm taller than the rim bed, that makes the total tire height 42mm. So that makes the tire 9mm taller than spec, it seems.

Is this normal? Has anyone measured the height on cx tires before?

BTW, I put some cheap 35 X 700 touring bike tires on the bike and the clearance was fine.

[mattr]

The 33 part of the tyre spec bears little or no resemblance to the actual tyre size, it's just a standard way of measuring tyre tread width.
I'm not sure if they even measure it on a rim.

Might be worth looking for the etrto measuring specification.

[xnavalav8r]

I thought the measurement was based on casing, not on the knobs. Either way it will vary with a rim of different width.

[mattr]

Ok. It may well be! I'm trying to remember a talk from Michelin 15 years ago!

Either way, what you measure with a tape will rarely match the nominal size! Especially on an mtb or cx tyre.

[mattr]

Oh, another thing. 33mm cross tyres are a bit of an oddity in that it's the maximum allowable width. So you may well find some funny sizing height wise.