Mountains bikes now come in three different wheel sizes.
Road bike standard wheel size.
The letter at the end of a tire size is a throwback to an old french system when the letters a b and c designated different inner tire diameters it does not stand for cm.
Bike frames are measured from the middle of their bottom bracket to the end of their seat tube.
When it comes to choosing width there are two major factors at play.
Racing bikes use the 700c size which has a tire bead set diameter of 622 millimeters.
A third type of tire size might appear on either a mountain or a road tire.
A tire size you might see on a mountain bike.
23c 25c and 28c their width in mm.
Because of the high pressure and desired low rolling resistance road tires come in narrow widths.
A tire size you might see on a road bike.
First consider what kind of bike you want sizing varies greatly between road and mountain bikes as well as between men s and women s models and even between.
Consider the bike type.
29 x 2 3 indicates a tire with a 29 outer diameter and a 2 3 width.
The 700c bit comes from a traditional french wheel standard based on the outer diameter of the inflated tyre 700mm.
If all three have a 15 frame there will be a height difference between them due to their wheel size.
Sometimes very small adult road bike frames will use a smaller wheel size like 650b but it s more common even for small frames to use 700c wheels.
Common road bike widths in millimeters come in sizes ranging from 18 to 23 with a typical road bike tire at 700 x 23.
A standard road tire is 700c x 23mm indicating a tire diameter of approximately 700mm and a width of 23mm.
Most adult road bikes use 700c wheels whereas 26 is typically a mountain bike wheel size although in recent years mountain bikes are using larger wheels as well.
When shopping for road tires you ll look for 700c x your preferred width 23mm being the slimmest option and going up to 36mm.
Standard road bicycle wheel size today is 622 mm and it usually takes tyres of 23 622 or wider 25 622.
You can find them with 26 wheels 27 5 wheels or 29 wheels.
Far and away the most common size for road bike wheels is usually referred to as 700c and has a bead seat diameter of 622mm.
700x25c indicates a tire with a 700mm outer diameter and a 25mm width.
This wheel size is the largest available for conventional bicycles giving a racing bike more stability at high speeds.
Today when off road bicycles with wheels larger than standard mtb wheels started to be popular it s wheels are marketed as 29 but in fact are 622 wheels with wider tyres so that outer diameter is close to 29.
Road tire sizes 700c.
Some older road bikes still have the 27 inch size.
