BMX inner tube: Schrader or Presta, and which size

A flat tube ends your session, and picking a replacement has two traps: the valve, Schrader or Presta, and the size. Get both right and changing it is a ten-minute job.

The three tubes at a glance

What to look for in a BMX tube, in order of importance

1. The valve your rim takes. Look at your old tube: if it has a car-type valve (Schrader), your rim has the wide hole; if it has a thin valve with a small locknut at the tip (Presta), it has the narrow one.
2. The wheel size. The tyre sidewall says something like 20 x 2.25 and, in brackets, 57-406: 57 is the width in millimetres and 406 is the rim diameter of a 20" BMX.
3. The tube’s range. Every tube covers a span of widths. Schwalbe’s no. 7 goes from 40 to 62 mm on 406, that is, 20 x 1.50" to 20 x 2.40": from a race tyre to a fat street tyre.
4. Wall thickness. A thicker wall resists pinch flats better, but weighs more.

Schrader or Presta: which suits you

A Presta valve can go in a Schrader rim with an adapter sleeve, as Park Tool explains; the other way round, it cannot. If in doubt, stick with the valve you had.

11. Schwalbe no. 7 Schrader: the go-to spare

This is Schwalbe’s standard 20" tube, with a 40 mm Schrader valve. It covers 20 x 1.50" to 20 x 2.40", so it fits almost any 20" BMX. The link is a pack of two: one to fit and one for your bag.

Specs and cons of the no. 7 Schrader

According to Schwalbe: butyl, 145 g, a 40 mm Schrader valve and sizes from 40 to 62-406 (also 54-428). The brand says it inflates every tube and stores it for 24 hours to check that it holds air. According to the Amazon.es listing, the link includes 2 tubes.

Cons: it is a standard tube; if you get pinch flats often, the Air Plus is built for that. Pros and cons ↓

22. Schwalbe Air Plus no. 7 Schrader: the one that resists pinch flats

Same size and same valve, with a thicker wall. Schwalbe gives it a 1.5 mm wall, about 70% more than a conventional tube, and says it protects better against impact punctures and holds air longer. It makes sense if you jump, drop in or ride street and pinch flats keep finding you.

Specs and cons of the Air Plus

According to Schwalbe: butyl, 220 g, a 40 mm Schrader valve and sizes from 40 to 62-406 (20 x 1.50" to 20 x 2.40"). The brand mentions up to 50% better air retention, depending on size and pressure. The link is a single tube.

Cons: it weighs 75 g more per wheel than the standard tube and will not save you if you ride on low pressure. Pros and cons ↓

33. Schwalbe no. 7 Presta: for narrow-hole rims

The same no. 7 tube, with a 40 mm Presta valve. It is the one you need if your rim is drilled for Presta, because a Schrader valve will not go through the hole.

Specs and cons of the no. 7 Presta

According to Schwalbe: butyl, 145 g, a 40 mm Presta valve and sizes from 40 to 62-406 (also 54-428). Schwalbe says the core of its valves can always be replaced. The link is a single tube.

Cons: you need a Presta-compatible pump and must undo the small locknut before pumping. Pros and cons ↓

Read your tyre before you buy

Find the size in brackets on the sidewall. If the first number is between 40 and 62 and the second is 406, any of these three will fit.

If you…, get…

If…	Get
Your bike is stock and your old tube is Schrader	Schwalbe no. 7 Schrader (pack of two)
You jump, drop in or ride street and get pinch flats	Schwalbe Air Plus no. 7 Schrader
Your rim has the narrow hole or your old tube is Presta	Schwalbe no. 7 Presta
Your tyre is wider than 2.40" (62 mm)	None of these: look for a tube whose range reaches your width

Why you get flats with nothing stuck in the tyre

If the tube has two parallel slits, it is a pinch flat: when you land or hit a kerb, the tyre bottoms out and the tube gets trapped against the rim. Park Tool’s fix: more pressure or a wider tyre. Always within the range on the sidewall.

Change the tube in six steps

1. Let all the air out: on a Presta valve, undo the small locknut at the tip first; on a Schrader, press the pin.
2. Push the tyre beads to the centre of the rim and lift them off with two tyre levers. Never with a screwdriver.
3. Find the cause: carefully run your fingers around the inside of the tyre in case something is still stuck in it, and check that the rim strip covers the spoke holes.
4. Put just enough air in the new tube for it to hold its shape and fit it inside the tyre.
5. Push the valve straight through the hole, pointing at the hub, and fit the beads by hand.
6. Pump it up within the range on the sidewall. A crooked valve or low pressure ends up cutting the tube next to the valve.

Steps based on Park Tool’s tyre removal and installation guide.

Common mistakes when changing the tube

• Ordering “a 20-inch one” without checking the width: make sure your tyre falls inside the tube’s range.
• Getting the valve wrong: a Schrader valve will not fit a Presta rim.
• Riding on low pressure: the fast track to a pinch flat. Check it with a gauge before you ride.
• Fitting the new tube without finding the cause: if the thorn is still in there, you will be flat again in two laps.
• Pumping blind at the petrol station: those compressors push air in very fast. Go little by little and watch the gauge.

With the wheel sorted, check the BMX tyres guide in case the tyre needs replacing too, and the maintenance guide to check pressure before every session. If you are still tuning up your bike, see which BMX chain to buy and the first BMX upgrades worth making. To try it out, find somewhere to ride in the skatepark, track and pump track directory. All guides are in buying guides; and the three tubes with verified specs are just below.

Frequently asked questions