Tyre and inner tube sizes



potto

New Member
Aug 6, 2010
10
0
0
Hi All,

Newbie question here:

I am running GP Force 700 x 23 tyre on the front and GP Attack 700 x 24 tyre on the front.

Inside (when I got the bike), they had a 700x20/28C (front) and a 700x18/25 (rear), so I have always just used these as replacement for punctures.. my question is how do these sizes relate to tyre sizes ? what is the 20/28 and 18/25 (I expected only 1 number, being the circumference, which would match the tyre size?)

Also I need some new tyres as current ones are getting bald. I have a 5 or 6 inner tubes for the current tyres around the house, so preferably the replacement tyres would be of suitable size to take these tubes, which circumference size tyre would I need?
 
potto said:
Hi All,

Newbie question here:

I am running GP Force 700 x 23 tyre on the front and GP Attack 700 x 24 tyre on the front.

Inside (when I got the bike), they had a 700x20/28C (front) and a 700x18/25 (rear), so I have always just used these as replacement for punctures.. my question is how do these sizes relate to tyre sizes ? what is the 20/28 and 18/25 (I expected only 1 number, being the circumference, which would match the tyre size?)

Also I need some new tyres as current ones are getting bald. I have a 5 or 6 inner tubes for the current tyres around the house, so preferably the replacement tyres would be of suitable size to take these tubes, which circumference size tyre would I need?

A range of inner tube sizes will work with a given tire. The different number that you see on your tubes just indicate the range that will work. So, the 20/28 will work with a tire between 18-28, hence, it works with your 23c tire. Likewise, the 18/25 will work with a tire between 18-25, including your 23c tire. It is really that easy! So, you don't need to put different tubes in your front and rear tires, and you don't need to worry about needing different tubes when you get new tires (although I would use a fresh set of tubes with the new tires, but that's just me).