Here’s the simple (and, unfortunately, not very helpful) answer:
700x50c (which is a measurement in millimeters) equates to around 27 ½ inches by 2 inches.
What’s the problem with this? Well, trouble is that, over the years, tire manufacturers have nudged dimensions a little here and then pushed them a little more over there. So that now, a tire that says it is 27.5” x 2.0” won’t necessarily fit a 700x50c wheel.
It might, but then again, it might not. This discrepancy can lead to issues with fitting the new tire or punctures down the road (literally) due to an ill-fitting tire.
If your existing tires are “700x50c” then only ever replace them with new tires that also say they are “700x50c”.
If you’re struggling to find replacement tires and tubes for your 700 x 50c bike wheels, then I’ve got some great recommendations for you in a moment.
I’ll also dig into what the numbers in “700x50c” mean, a little more detail on what the issues are with using an incorrectly sized tire, and how to choose the right tires and inner tubes for your bike.
Plus, I’ve got a quick reminder on the tools and method for fitting a replacement tire and tube.
Let’s dive in.
What does 700x50c really mean?
“700x50c” is the size of your bike tire and it’s measured according to the ‘French system’.
Breaking the size down into bite-size pieces, we can see that:
“700” is the nominal tire diameter in millimeters.
“50” is the approximate width of the tire (also in millimeters).
“c” refers to a width code that was part of the French system. You can safely ignore it today (a 700x50c tire is the exact same as a 700×50 tire). However, back in the day, the French system classified tires into four widths (‘a’, the narrowest, through to ‘d’, the widest).
Why is there a problem with swapping from 700x50c to inches?
It should be easy to swap tire sizes from millimeters to inches. But, sadly not. The problem is that the dimensions used for tires are referred to as ‘nominal’. This can mean a number of things. In the case of tires it means that the sizes given are approximate and don’t necessarily correspond too closely to the actual dimensions of the tire.
Yeah, you should be.
What’s happened is that, over time, actual tire sizes have drifted gently away from the advertised tire sizes.
It might be due to tolerances in the manufacturing process.
Possibly, tire companies shave a little of the rubber off the tire in order to reduce the weight…
…or add a little more rubber on to give the tire more of a tough, gnarly appearance.
Whatever the reason though, it means that tires which seem to be ‘just about’ close enough…probably aren’t close enough in reality.
And a tire that doesn’t fit correctly may well lead to problems down the line.
So, as with most areas in life, you need the right tool for the job. In this case, it’s a tire (and tube) that is 700x50c for a 700x50c bike wheel.
Now where would we find those?
What size bicycle tire do I need?
The best way to ensure that you choose a tire that fits correctly is to pick one that says it is “700x50c”.
The tire pictured is 700x50c and is perfect for riding on a variety of terrain, including pavement, roads, gravel and light- to medium-duty trails.
If your cycling is purely on smooth surfaces, such as a pavement and roads, then go with a tire that has a tread pattern which is smoother and more closed. This 700x50c tire is a great choice.
What bike inner tubes should I buy?
For inner tubes, buy a replacement which has the same diameter as shown on your tires (in our case, that’s 700) with a width measurement that covers the tire diameter (50 for our tires).
Inner tubes blow up like balloons so, whilst the 700mm diameter won’t change, the width will vary according to how inflated it is. For that reason you’ll see tubes marked with a diameter and a width range (such as “700 x 50-52”).
A tube like that can be used for tires of 700×50 up to 700×52.
How do I replace bike tire and inner tube?
Changing bike tires and tubes can be a fiddly process but, with the right tools and a little know-how, it should be straightforward and take around 30-40 minutes per wheel.
It’s good practice to always take a spare tube out with you when you go for a bike ride. Pack a tube, tire levers and a small pump (I recommend a CO2 tire inflator for this) and you’ll be well-prepared for any punctures that you get when you’re out on the road.
The process for replacing a tire and tube is as follows:
- Undo the quick-release bolts on each side of the hub and remove the bike wheel
- Use the tire levers to lift one edge of the tire over the wheel rim
- Remove the tire (if you’re planning on replacing this, otherwise leave it on the wheel rim)
- Remove the inner tube
- Check inside the wheel rim to make sure there’s nothing that will damage the new tube (thorns, broken glass or grit can do this)
- Partially inflate the new tube and fit it around the wheel rim, ensuring that the valve is correctly centered in the hole of the wheel rim
- Fit both rims of the new/existing tire over the tube
- Fully inflate the tube, ensuring that it’s correctly settled in the tire and not pinched
- Fit the wheel back onto the bike, ensuring that the quick-release bolt is fully secured
For a video walk-through of this process, see the demonstration below.