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10-01-01, 10:33 AM
Since there seems to be a lot of confusion regarding different wheel/rim sizes, let me just take this opportunity to further obfuscatethe situation:
700c wheels:
These are called "700" not because of the rim diameter (which is actually 622mm), but rather the approximate diameter of the "traditional" tyre. In some places, these are also referred to as 28" tyres. Many tubulars still use this obsolete naming convention.This is confusing! Tyres with 635mm rims (ancient Raleigh roadsters, some traditional bikes still made in India, China) are the only proper 28" tyres! A 700 tyre, whether tubular or clincher, is not the same as a 28" or a 27" tyre!!!
27" wheels:
These are referred to as 27" because that was the approximate diameter of the tyre. They were originally intended to be a lower profile tyre than the big ballon tyres of the day, hence, they are a smaller # than some tyres which are on smaller rims! These tyres sit on 630mm rims, and are not interchangeable with 700c tyres! This size has been obsolete for about 10 years now.
26" wheels:
Depending on the type of bike, a 26" tyre could be mounted on a rim of 571mm (650c), 597mm, 590mm, 584mm, or 571mm. None of these tyres are interchangeable with different rims, and there are actually 2 different 597mm type rims!
When you are looking for a tyre to fit a rim, always look for the ertro # on the rim. Then, look for the similar # on the tyre.
700c wheels:
These are called "700" not because of the rim diameter (which is actually 622mm), but rather the approximate diameter of the "traditional" tyre. In some places, these are also referred to as 28" tyres. Many tubulars still use this obsolete naming convention.This is confusing! Tyres with 635mm rims (ancient Raleigh roadsters, some traditional bikes still made in India, China) are the only proper 28" tyres! A 700 tyre, whether tubular or clincher, is not the same as a 28" or a 27" tyre!!!
27" wheels:
These are referred to as 27" because that was the approximate diameter of the tyre. They were originally intended to be a lower profile tyre than the big ballon tyres of the day, hence, they are a smaller # than some tyres which are on smaller rims! These tyres sit on 630mm rims, and are not interchangeable with 700c tyres! This size has been obsolete for about 10 years now.
26" wheels:
Depending on the type of bike, a 26" tyre could be mounted on a rim of 571mm (650c), 597mm, 590mm, 584mm, or 571mm. None of these tyres are interchangeable with different rims, and there are actually 2 different 597mm type rims!
When you are looking for a tyre to fit a rim, always look for the ertro # on the rim. Then, look for the similar # on the tyre.