Gravel and cyclo-cross tyres

35–40 mm: faster riding, mixed terrain (asphalt, gravel)
40–45 mm: a universal compromise for comfort and grip
45–50 mm: more technical terrain, more comfort, more traction

When choosing the right tyres, the inner diameter of the tyre and its width are important. The inner diameter of gravel and cyclo-cross tyres is most often 700 mm (28 inches). You can pick from tyres and tubes, which are available in different widths and with different tread patterns. With wider ones, you may be limited by the width of the rim or the space in the bike frame, so check the recommendations of your component manufacturers. For some products, you will find the TPI (threads per inch) number. The higher the number, the lighter the tyre and the lower rolling resistance, but it is also less durable. Tyres may be suitable for tubeless use, this information is listed with the product. To install the tube, you will need a special glue or double-sided adhesive tape designed for this use.

What is the difference between a gravel tyre and a cyclo-cross tyre?

Cyclo-cross (CX) tyres are typically narrower (33 mm max) due to racing rules, designed for short, intense rides in mud and grass.
Gravel tyres are wider (35–50 mm), designed for long rides, gravel, forest roads and asphalt. They offer more comfort and stability.