Road Bike Tires and Wheels?

[michaelscycles]

I do not know much about the sizing for road bike tires and wheels. I have someone that needs new wheels for her road bike. It has 700 x 25 tires on it. Most of the wheels I found are 700 x 20. Will they work together?

Thanks,
Mike

 

[user 135]

Here is the book on tires and wheel sizing.
http://www.sheldonbrown.com/tire-sizing.html#width

 

[michaelscycles]

Here is the book on tires and wheel sizing.
http://www.sheldonbrown.com/tire-sizing.html#width

Thanks, I checked that out before. Still wasn't sure because I don't know how they measure the wheels. I don't have them here to do it myself. Is a 700 x 20, 20mm from idside to inside, or is it the outside measurement?

Thanks!

 

[No cars on mars]

Here is the book on tires and wheel sizing.
http://www.sheldonbrown.com/tire-sizing.html#width

Thanks, I checked that out before. Still wasn't sure because I don't know how they measure the wheels. I don't have them here to do it myself. Is a 700 x 20, 20mm from idside to inside, or is it the outside measurement?

Thanks!

20 mm is the width of the tire like 1 1/4 or 2.125 inches
700mm is the outside diameter of the tire, not the wheel, like 27 or 24 inch tires
A 26 x1 3/8 will not fit on a 26 x 1.50. They are different size wheels but when both are on their correct wheels both will be 26 inch in diameter. Outside rubber to rubber diameter. Do not mix fractions with decimals.

If you are changing a 27 or a 26 inch wheel for a modern 700 the only adjustment you have to make is moving the brake pad up or down.
A 700 x 25 tire should fit on a 700 x 20 wheel but will be wider side to side. 25mm is a little bit over an inch in width while 20mm is about 4/5ths of an inch wide. So the answer is YES.

Ask at your local bicycle store. If they do not know, run very fast out of the store.

 

[deorman]

Yes. :lol:

 

[deorman]

Any tire having an ISO #(bead seat in mm)of 622 will fit 700c rims. This includes some inch measure "28" and "29" tires, as well as those marked for 700. There is also a 700b, but the chances of you running into one are pretty small in this hemisphere. :wink:

 

[michaelscycles]

Thanks everyone. I found a chart in a repair manual that cleared it up for me. It says that the recommended tires for a 20mm rim are 19-32. So the 25 I need to put on should be perfect.