Time for a new tire

[raceman]

alright. i'm a little confused about tire sizes. My tire measures 3.5'' in width and my rim is an 18". When i go online and look at tires it gives me tire measurements like this 110/100-18 i know that last number is the rim size that it will fit on but what number is for the width?(i know those numbers are in mm so 3.5 would be 90mm i just don't know if the first or second number is for the width). someone please help me. also would a 4" tire in width fit on a 3.5'' rim?

[Guest]

A 110/100 x 18 tyre is 18" in diameter. The 110 is the width in millimtres (110 being about 4.25 inches) and the 100 figure is the aspect ratio - that's the relationship of the height of the tyre to it's width

so a 110/100 is 110 mm wide x 110mm deep

170/60 is 170mm wide and 102 mm deep (60 % of 170mm)

Don't think that a wider tyre will automatically give you more rubber on the road or better grip. If you fit a wide tyre to a narrow rim it will be pinched out of shape so it's actual profile will be distorted.

[Scouse]