700c or 28inch? What’s The Difference?

When searching for bike tyres, it can often leave you scratching your head in confusion.
Understanding how to navigate the language of bike tyre sizes will help you find the perfect
tyres for your wheelset.

Let’s start by looking at the main sizes in the industry; 26”, 27.5”, 29”, 700c and 650b. The 26”
will be on older bikes, mainly mountain bikes. The 27.5 is a larger mountain bike tyre, so in turn
the 29” is an even bigger mountain bike tyre.
Don’t let the sizes 650b and 700c throw you off, when looking at these sizes literally, they
equate to the same measurements in inches. For instance, the 700c is the same as a 29” tyre
and the 650b is equivalent to the 27.5”.

Checking your tyres

Now we need to look at the codes on your tyres. On the sidewall of your tyre will be the specific
code for that tyre. These numbers represent the width and bead seat, if we use an example;
38-622, 38 being the width and 622 is your Bead Seat Diameter (BSD). The BSD is what you
really want to focus on, as this is what governs which tyre will fit on what rim.

700c Tyre
The 700c is a standard road bike size, it originates from France as the approximate measurement for the
diameter of the wheel. As previously mentioned, they are mainly used for road and gravel bikes.
If looking for the mountain bike equivalent, 29” would be the close match. Both sizes will have a
622 BSD so you could alternate the tyres between either a mountain bike or road bike.
However, if you want to do so, make sure the tyre fits comfortably into the frame but also ensure
the rim isn’t too wide for the tyre. In essence, the 700c and 29” wheels are very much
interchangeable.

28” Tyre
The 28” tyre is a non standard size used mainly by German companies. This size again, has the
same beat seat diameter of 622, as 700c and 29” tyres. So they are also mostly compatible, but
take caution as some 28” tyres have variations between their BSD’s, some have a 635 BSD;
such as Rod Brake Roadsters which call themselves 700b.

Why Are They Listed Differently?
The sizings alternate due to the method in which the measurements are taken throughout
Europe and the UK constantly fluctuating and changing. It is also down to marketing, some
companies market a tyre at 25c, when it is really a 23c in order to advertise a lighter tyre over
their competitors. This constant shifting between sizing makes it much harder to steer through
the sizes, particularly if you are new to the industry.
To ensure you are opting for the correct right tyre and accurately differentiating between the
many tyres on the market. Simply make sure the number on the tyre is relevant to the bead seat
diameter.

Conclusion
So in answer to the question whether 700c and 28” tyres are the same? In short, in most
circumstances they are, however there is occasionally a slight variation from previous
standards that differ causing the BSD to change accordingly.