Single Speed Conversions: What Kind of Bike Do You Have?

So what kind of bike are we trying to convert to single speed here? You probably know this, but even if you do it's probably worth reading on as we want to be 100% clear on what size and type of wheels we are working with.

You probably have one of five types of bicycle:

  1. A modern road or track bike with narrow 700c wheels
  2. An older (pre around 1990) British road or track bike with 700c or 27" wheels
  3. A mountain bike with 26" Metric Wheels (559mm Diameter)
  4. A modern hybrid bike with wide 700c wheels
  5. A town bike, perhaps with 26" Imperial Wheels (590mm Diameter) but who knows (most new town bikes now have wide 700c wheels)

We're hoping you have some wheels on your bike, and tyres on them, because we want to identify the size of wheel your bike works with, but also from the wheel size we will get a decent idea of the kind of frame you have - we need to know both.

If you just have a frame or for some other reason have no wheels then you may still recognise your bike type from the list. If in doubt get in touch and we can see if we can figure it out together.

Tyre Size - for Wheel Diameter and Width

Look at a tyre on one of the wheels - it will probably have some writing on the side walls somewhere. Take a look at the table below and see if you can identify your wheel and bike type. You're likely to find one if not both of the 'ISO Diameter' and 'Common Label' items on the tyre somewhere. You may see other stuff which is there to confuse! Notice two things in this table:

  1. Three kinds of bike all have the same diameter wheel - 700c. Really it's two main categories, Road/Track bikes and Hybrid bikes. Odds are you know what you have anyway and are just confirming the wheel size but a key clue is the width of the tyres. On a Road/Track bike they are narrow, 23mm-28mm usually, on hybrids likely to be 28, 32, or 37mm.
  2. Town Bike and Mountain Bike wheels both contain 26" in their common label - this is why we need a table like this. It is also why the ISO figure can be useful. The ISO number is the actual diameter of a particular part of the tyre and indeed of the rim on the wheel (usefully). You will see that this differs on these two kinds of wheels. So we need to be clear which you have.
Type of Bike Type of Wheel ISO Diameter Common Label - Gives Diameter and Tyre Width Photo of typical tyre
Modern and some older Road/Track Narrow Rim 700c Wheel 622mm

700c x 20mm, 23mm, 25mm, 28mm or similar

(28mm could be a hybrid bike too, you may have to look at other features)


Modern Road/Track 700c Tyre

Traditional British Road/Track 27" Wheel 630mm


27" x 1 14"


Traditional British Road Tyre

Mountain Bike 26" Mountain Bike Wheel 559mm

26" x 1.95, 2.25, or similar decimal number

 Mountain Bike Tyre 


Modern Hybrid Bike (and some Town Bikes) Wide Rim 700c Wheel 622mm

700c x 28mm, 32mm, 37mm or similar

(28mm could also be a road bike, so if you're not sure you may have to look at other features)

 Modern Hybrid 700c Tyre


Town Bike 26" x 1 38" Wheel 590mm 26" x 1 38"  

Single speed kit

Once you've worked out what you have head over to our Single Speed Conversions: Do You Have a Freehub Wheel? page to check if you have a Freehub wheel on your bike or not, and then back to the Single Speed Conversions: Everything You Need To Know page so we can get to the next stage.