+1 "Most" modern sewups are 700c but in certain European countries they were occasionally marked 27" or even 28".

More recently 650 and 26" tubulars were introduced for smaller sized frames and specialty racing bikes.

There were also 20" and 24" tubulars used on kid's racer bikes.


A Continental cyclocross tubular from the late 70's marked 27 x 1 1/8 - these tires were 700c x 28mm. This one is about 38 years old, still hold air and is probably rideable!



Sewups rarely had or have sizes marked on them. In general, they range from 700c x 18mm to 700c x 32 or even a few larger ones for CX (cyclocross).

You had to look up the specs in catalogs to find the published sizes.

My all time favorite sewups were Clement Red Label cotton Paris-Roubaix tires. They had a 28mm cross section. Next were Clement Del Mundo setas (silks). Their cross section was 26mm. The Paris-Roubaix setas were 25mm.

Most popular road sewups were 22mm to 24mm. CX tires ranged from 25mm to 32mm.

Sewups stretch over time plus manufacturing variances probably influenced tire makers reluctance to use dimensional markings on the casings.


WAYY back in the day, many bikes used tires with the tubes sewn into the casing. I remember a few bikes form the 1920's to the 1940's that our shop owner had in his collection. The tires were 28" and maybe 30" with a 2" to 2 1/2" cross section. they were glued on just like modern sewups.

Check out some of the boa constrictors that the racers used back in the first 40+ years of the last century.


verktyg

Chas.