Ciclocross

The size or width of the tyre depends entirely on how you define your gravel bike and on which grounds you mainly ride. Some of the most common sizes for gravel tyres can be found in the table:

Wheel size	French designation	Inch dimension	ETRTO
27,5"	-	27,5x1.20"	30-584
28"	700x30C	28x1.20"	30-622
27,5"	-	27,5x1.35"	35-584
28"	700x35C	28x1.35"	35-622
27,5"	-	27,5x1.50"	40-584
28"	700x40C	28x1.50"	40-622
27,5"	-	27,5x1.75"	47-584
28"	700x45C	28x1.75"	47-622
27,5"	-	27,5x2.00"	50-584
28" (29")	700x48C	28x2.00" (29x2.00")	50-622

Tyre widths of 30 or 50 mm are rarely used and only for very on-road or off-road oriented tyre models. The majority of all-round tyres has a tyre width between 35 mm and 45 mm. Except for: Cyclocross tyres usually have a size of 700x33C (ETRTO: 33-622), as the UCI does not allow wider tyres for cyclocross races.

The tyre tread pattern, like the tyre width, depends on the preferred use. Do you want to cover many kilometres and prefer to ride your gravel bike on the road and on easy forest paths? Or do you love shooting down gravel tracks and riding on easy trails? It is crucial to choose the right tyre, the number one tuning part on a gravel bike.

Tyre width	Tread	Focus	Rolling resistance	Offroad grip	Intended use
Narrow	Lightweight	Speed	Low	Low	Road, dry forest paths, fine gravel
Medium	Moderate	Versatility	Moderate	Good	Mixed terrain, coarse gravel, damp forest soils
Wide	Strong	Fun	High	High	Coarse gravel, wet natural ground, rocky ground, easy trails

In practice, there are also combinations of wide tyres with little tread pattern (more damping on the road, riding on sand) or narrow tyres with a deep tread pattern (mud tyres, cross tyres). Therefore, the table only provides a rough categorisation for basic understanding.

In short: More comfort, more traction, more puncture protection. The decisive factor here is not only the larger contact patch, but also the lower air pressure. But even if the frame and fork allow for very wide tyres, the sweet spot of the right tyre size is very individual and depends on many factors such as riding style and preferred ground conditions. However, it is worth experimenting with wider tyres. There is a reason why some riders switch from 28-inch to 27.5-inch wheels, which allow for wider tyres in the same frame.

Every manufacturer specifies maximum tyre widths for the frame and fork. The ROSE Backroad (MY2020 until 2023), for example, allows for tyre widths of up to 45 mm for 700C and up to 47 mm for 650B. If you can't find out the maximum tyre width, you'll have to use your best judgement – at your own risk, of course. What’s important: It is not enough for the tyre to fit when the bike stands. You should always take into account the (sometimes considerable) twisting of the wheel when cornering, as well as the deformation of the tyre due to the rider's weight at a given air pressure. The tyre should therefore have several millimetres clearance on both sides to avoid rubbing against the chainstays or fork bars when riding.

A clear yes. Gravel and cross tyres benefit just as much from tubeless tyres sealed with liquid latex as their MTB counterparts. The most important advantages are:

• Better puncture protection thanks to "self-fixing" tyres
• Lower air pressure is possible, thus more comfort/grip
• Less rolling resistance thanks to missing inner tube
• Weight saving (depending on the previously used tube or amount of sealant)

You will already notice this on the road. However, the more you turn off the road, the more the aforementioned advantages come into play. Thanks to the wider tyres and lower air pressures – in contrast to road bikes – mounting is often easier and there are fewer problems with sealing.