Other disciplines are seeing progress too, but for their hyperactive growth in the industry, gravel and adventure bikes still seem to be a niche market in terms of tyre sizes. In order to prep my own Cyclocross bike for some generally heavy trail shredding, I did some cherrypicking and found the top options for adventure/trail 700c tyres available on the market today.
As with any bike, the first step in choosing tyres is frame clearance. For most CX and gravel bikes that weren’t really designed with heavy trail riding in mind, the maximum tyre width still allowing for mud clearance is around 45mm. Keep in mind, bike frames vary wildly, even within the same discipline, and different brake types can have an effect on tyre clearance as well. Here’s a pro tip… Measure! The internet is no match for a good tape measure at your side kid.
I do not know what the tyre clearance is for this bike, for example.
I measured my max clearance at 5.5cm, so anything under 50mm (about 2") should be okay.
Normal UCI-sanctioned CX tyres are around 33mm wide, so a 45mm tyre actually does represent a significant change in width. The more difficult option to consider here is whether to explore 29” tyre options in addition to the 700c diameter tyres. Wheel diameter for these tyres is identical, but 29ers tend to bulge out more and require a wider rim. This means that seatstay-bridge and bottom-bracket clearance need to be paid extra attention to if you’re trying to fit a 29” tyre on a 700c bike. In general, CX rims can support a 29” width of up to 2”, but most frames limit safe clearance to about 1.8” or so.
If we’re looking for some extra beefy rubber for this kind of frame then, it should measure around 700x45c or 29x1.8”. Surprisingly, these sizes are still relatively sparse. The most luck you’ll have for now is in the 700x42-45c category, since mountain bike tyre manufacturers assume that 29er riders will go no smaller than the width of 6-10 dime toads, to ensure maximum toad-squashing capacity.
dime toad scale picture
We’ll start with these toad-squishing 29ers.
29er Option 1: Kenda Small Block 8 This one’s a classic, and has always been popular with racer folk. The tread is versatile, but if you’re doing anything really nasty you might want something with a little more bite to it. Kenda sells the Small Block 8 in the normal toad squishing size of 2.1”, and they have a 1.9” variant for those who like to avoid as many toads as possible while stilling rolling over anything. The 1.9” width can be pushing the limit of clearance on many bikes, but if you can mount this tyre and the wheels still spin, it’s a solid option for any offroading.
29er Option 2: Vee Rubber X-C-X Finding a 29” tyre smaller than 2” wide is enough of challenge, but to find a 29x1.75” you must have done something to please the niche-market gods. This one is also available in a 1.95” width if your frame can handle it, and the tread looks deep enough to handle some real trail riding without taking away the fast rolling nature of an adventure bike on multiple terrains.
29ers are great, but sometimes you want a tyre that can slice rather than squish, especially for those times that you encounter snakes. 700c widths are more narrow and don’t bulge out from the rim as much, so they’re the better option if you’re worried about tyre clearance.
700c Option 1: Continental Double Fighter III The allure of these tyres is the 700x50c option. This is pushing the limit of some frames, but it also comes in a 700x37c if 50mm stretches your waistline a bit too much. These tyres have a minimal tread and are geared more towards gravel riding than any off-road escapades, but their width and raised edge-nobs makes them seem like a good choice if any rough singletrack is a rarity.
700c Option 2: Panaracer Fire Cross K Panaracer has been around making bike tyres for a long time, but it’s become rare to see them out in the wild as brands like Maxxis and Kenda seem to take center stage. Nonetheless, this tyre seems to be in the right place when it comes to singletrack on 700c rubber. 700x45 is the butter zone for clearance, and the tread looks like what you might find on a 29er. This tyre may be slower on the grass or gravel of a normal CX race, but the large, deep treads look to inspire a lot of grip.
These tyres are the only ones I've found so far that fit in the goldilocks range of width, but there are also plenty of tyres around 40-42c that could make good candidates for making your Cross or adventure bike a little more rugged. Ultimately, it depends upon what you're planning to do with the tyre and how cool you want your steed to look, and if you're riding singletrack and have the clearance for it, go as wide as you want.