Which Tredz Inner Tube Fits Your Tyre, Rim and Valve?

If your bike needs one new inner tube and you want another for your saddle bag, check both tyres before buying a pack. The front and rear may take different widths. At Tredz, the details that decide whether a spare will work are the diameter and width printed on the tyre, the valve that fits your rim and the length of stem your pump can reach.

Read the two numbers on the tyre

Photograph the writing on the sidewall while you have the bike in front of you. Look for a pair of numbers separated by a dash. In the ETRTO marking 25-622, the first number gives the nominal tyre width, 25 mm. The second gives the tyre’s inner diameter, 622 mm, at the point where it seats on the rim. Tredz’s sizing guide lists the same size as 700 × 25C. Either marking is a better starting point than the bike’s make or model.

The tube needs to cover that diameter and the width of the tyre. A tube labelled 700 × 20–25C covers a 700 × 25C tyre, while a 700 × 32C tyre is outside its stated range. Both wheels may be described as 700C. Use the width range on the exact variant you plan to buy, especially when a product page offers several sizes under the same name.

If you are buying for two bikes, write down one line per wheel. The same spare can serve several wheels if their sizes fall within its range and the valves suit them all. If a marking has worn away, take the bike or a clear photograph to a cycle shop before ordering.

Match the valve as well as the wheel

A Schrader valve has the broader shape familiar from a car tyre. A Presta valve has a slimmer stem and a small threaded tip. The rim opening and your pump head matter here. Start with the valve type already fitted and check that the pump you carry accepts it.

There is a second measurement on many Presta listings. Tredz lists a Continental Race tube in a 700 × 20–25C option with a 42 mm Presta valve. Here 42 mm refers to the stem length. On a deeper rim, more of the stem sits inside the rim, so a tube with the right tyre dimensions can still leave too little valve exposed for the pump to grip. Use the specification of a tube that works on that wheel, or check the rim maker’s guidance for the length you need. Measuring only the visible part of your old valve will give a shorter figure than its full length.

Price the number of spares you will use

Tredz’s delivery table lists £2.95 for standard UK mainland small-item orders below £50 and free delivery over £50. Check the quote for your postcode and basket, particularly at the threshold or outside the standard mainland area. Postage matters more on a small order than the shelf price alone suggests.

Suppose a single tube costs £6 and a pack of three compatible tubes costs £15, with £2.95 delivery in either case. These are illustrative prices. One tube delivered costs £8.95. The pack costs £17.95, or about £5.98 per tube if you use all three. But if you need two, buying two singles in one order costs £14.95. The decision is whether a third spare is worth another £3 to you. A spare that fits neither of your other bikes has limited value once the first two are accounted for.

With your variant and quantity chosen, check whether a Tredz discount code applies to that basket. Compare the amount payable including postage after any reduction.

Compare the same spare at Evans Cycles

Evans Cycles also lists a Continental Race 28 tube for 700C tyres from 20 to 25 mm wide with a 42 mm Presta valve. That gives you a like-for-like comparison with the Tredz option. Check that the selected version is available, then look at the Evans Cycles discount code page if you want to compare offers. Use the same number of tubes and include any charge for delivery or collection. Save a note of the winning specification alongside your tyre photograph so the next replacement takes one check instead of another round of guesswork.