What size wheels does my bike take?

Question

I measured the wheel diameter on my road bike, which is probably from the 70's. The wheels (tires included) measured 27 inches. I see mostly 700c tires sold online, but I have no idea what that means. Does anyone have any idea how to determine the appropriate wheel size?

Answer 1

You can probably use either one.

27 inch wheels were used on Japanese road bikes from the 70s and 80s. 700c wheels were and still are the main size for european and US made bikes.

You may well be able to put on 700c wheels onto the frame, but you will probably have to adjust the brakes a little bit because the 700s are slightly smaller than the 27s. There is no real advantage to either except that tires and tubes for the 700s are much easier to buy, as that is now the mainstream size.

My advice: go to a bike shop, have them put on some 700c wheels and see if they fit ok(they probably will), and see if they can adjust the brakes for you.

Answer 2

Should be marked on the side of the tire.