What Size Tyre and Tube Do You Need?

There are four standard sizes of wheel, as determined by their different diameters. This page discusses this. Knowing this is the starting point, then read on.

Width of Tyre

Tyres come in different widths, roughly corresponding to how you want to deal with the trade off between speed (produced best by a narrow tyre) and stability and shock absorbtion (by a wide tyre).

But you can not put all widths of tyre on a particular kind of wheel. Here's the situation for each kind of wheel:

27" Road and 26" Town Bike Wheels

In these sizes of wheel almost all tyres will say they are of the same width - 27" x 114"  (1 1/4 is the width) or 26" x 1 38" (1 3/8" is the width). In actuality the tyres may vary a little in their width, but there is only one basic size of wheel rim so all tyres with these labels will fit on all wheels of the size.

The exception is that we have come across 27" x 1 1/8" tyres which do fit a 27" x 1 1/4" wheel. Indeed we sell these tyres (in a Continental model). However, do not apply this logic to 26" tyres, you can not fit a 26" x 1 1/4" tyre to a 26" x 1 3/8" rim.

Likewise, inner tubes for these wheels come in one size only.

Road Bike 700c and Mountain Bike 26"

On 700c wheels the rim of the wheel can come in various widths. These should be accompanied by similar tyres - so if you have a narrow rim you don't want to put a very wide tyre on it. If you have a very wide rim likewise you should avoid a narrow one. It will cause flat tyres to happen a lot more regularly and can affect handling too.

On this webpage – www.sheldonbrown.com/tire-sizing.html - is a table which tells you the appropriate tyre widths depending on the width of the rim on your wheel.

If you are purchasing 700c wheels then please see the individual product pages for details of the width of tyres they can accommodate.

The iconic knobbly 26" mountain bike tyre is usually 1.95" wide, but you can actually get mountain bike tyres from as little as 1.0" to over 2.5" in size. Wheel rims are usually 1.25” wide but there are also narrower ones on some more recent bicycles.

While a narrow tyre on a wide rim could create difficulties with more punctures than usual our experience is that tyres as narrow as 1.0” wide are not susceptible to punctures and provide good handling with older and new mountain bike rims.

For both 700c and MTB 26" tyres there are various inner tubes available which are suitable for a range of widths of tyre. Make sure you get the right tubes for your tyre width.

A final point - we don't offer any slick mountain bike tyres range on the website, however we have access to quite a range of them - from Schwalbe, Continental and Michelin. If you want more information about what we can get just get in touch.

More information

More discussion of the myriad of tyre sizing standards and tyre and rim width choices is available here:www.sheldonbrown.com/tire-sizing.html