700mm = 27.5 inches
23mm = 0.9 inches
WARNING! You can’t just convert the numbers to inches, unfortunately – read on for an explanation. Plus, I give you a recommendation for a correctly sized tire and inner tube.
700x23c is just the sizing of the bicycle tire. Measured according to what was historically referred to as the ‘French system’.
Let’s take a look at that in a bit more detail. ‘700’ is the first number and that is a reference to the approximate (or nominal) diameter of the tire. It’s sized in metric using millimeters.
‘x’ just means multiplied by – nothing fancy there.
‘23’ is the next number and that’s the approximate width of the bicycle tire (again it’s using millimeters).
Finally, the ‘c’ is an identification code for the width of the tire (looking at your bike from either in front or behind, this is the part of the bike tire that you see). In fact, these days the ‘c’ part of the tire identification is generally obsolete. However, it used to be a part of the old classification system used in France that gave width codes going from narrowest (called ‘a’) to widest (‘d’). This would mean that a ‘c’ tire like we have here would have been almost the widest you could get.
Finding your bike tire size
With most tires, this is a fairly simple process. Phew!
Crouch down next to your wheel and have a good look at the tire sidewall (make sure you’re looking at the strip of rubber which is above the metal wheel rim at the point where the brake pads connect). If you’re not sure where exactly to look, stand on one side of the bike (with your bike tires making a round ‘O’ shaped circle). The tire sidewall is now the rubber strip that you’re looking at. It’s likely to be smooth surfaced and, on some tires, will even be a different color to the rubber that touches the road surface.
Look at the sidewall closely and you’ll see numbers and possible words printed or embossed onto the rubber. You may see the tire brand e.g. Continental and you should also see our bike tire code “700x23c”. So, just to recap. Your tire diameter is “700” and tire width is “23c”.
Ok, so what tire size do I need?
This is the easy part!
When you’re buying your new tires, just ensure that it explicitly says it is “700x23c”.
There are lots and lots of different tire sizes on the market. But, sadly, tires that are ‘nearly but not quite’ close enough probably won’t actually be a good enough fit for your wheels. You might be able to get away with it, but you could also get a range of issues like punctures.
Is it worth the risk?
However, you can make a couple of choices: (a) the brand that you want to pick and (b) how knobbly you want your tires to be. For road bikes, I’m keen on smoother tires with little grip. They tend to be faster and give less vibration through the handlebars and saddle. If you’re likely to be riding in wintery conditions though, when it can be icy and slippy, then it’s a good idea to go with a tire that has more grip and knobbles.
In our household, we’re big fans of Continental tires and I’ve always been happy with the quality. They’re fast, smooth, and (touch wood!) I haven’t had to repair a puncture yet. Want a recommendation? Well, then I’d go with these tires.
Fast, light and puncture-resistant. Look at the listing and you’ll see that they come in a number of different sizes, so make certain you choose the 700x23mm.
Tires? Check. Now, what about inner tubes?
You’ll be pleased to hear that choosing 700x23c inner tubes is just as simple as tires!
You just need to make sure that you go for a tube that has a diameter matching the one embossed on your tire (‘700’) and that also has a width range covering the size you require (‘23’).
It’s worth knowing that tube widths change depending on how much air you inflate them with (just like a kid’s balloon). Because of this, you’ll find them sold according to a fixed diameter and a width range e.g. “700×23-25”. Using that example you can use this tube with tires that are between 700x23c and 700x25c.
If that sounds complicated, don’t worry. Here’s a fantastic inner tube that uses the standard Presta valve.
It’s worth a quick mention of the Presta tire valves. Car tires have a different type of valve (known as Schrader). So, if your pump is designed for that type of valve, then you’ll need to grab an adaptor like this.
This will convert your pump so that it can be used with either Schrader or Presta valves. You can’t get away from this, unfortunately, as Presta valves are a different shape to Schrader. Have a look at the Amazon pictures and you’ll see how easy these adaptors are to fit and use.
Tires? Check. Inner tubes? Check. How do you fit them on your bike?
With the right kit, the right knowledge, and a bit of prep, you’ll find that tires and inner tubes should be fairly simple to fit.
Just ensure that, whenever you go out cycling, you take a couple of inner tubes, small repair kit, tire levers, and a pump. Changing a tire and tube should then take as little as 30-45mins to complete.
There are five basic steps to fixing a flat tire:
- Remove the bike wheel
- Remove the tube
- Find the cause of the flat
- Repair or replace the tube
- Reinstall the bike wheel
For an easy how-to guide, have a quick watch of this video.