Bontrager GR1 TLR Team Issue Gravel Tyre

The Bontrager GR1 Team Issue Gravel Tyre is a dedicated dry-weather gravel tyre designed for one purpose – going fast in the dry. They do that very well – if you can guarantee such conditions in typically muddy, soggy Britain.

• Pros: Light weight, fast-rolling on smooth surfaces
• Cons: Little grip in the wet/on mud/in leaf matter; only one size

Reflecting the 'Team Issue' label, Trek does indeed issue the 40mm GR1 to its team riders – Sven Nys rode the GR1s on the second 50 miles of his ill-fated Dirty Kanza 200 attempt this year, after his chosen tyres suffered repeated flats. The GR1s performed well, but he pulled out after suffering stomach issues.

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Weighing in at a claimed 430g apiece (our test pair weighed 850g), the GR1s are light for a tubeless gravel tyre – comparable offerings from Schwalbe weigh a bit more – the 455g G-One, for example (and those are £58.99 rrp). The GR1 comes in just the 40mm size, matched by the slightly more open-tread and heavier 40mm GR2 at 440g.

I found the GR1 looser than most tubeless tyres I've fitted; it took an extra five layers of tape to build up a workable rim bed on some non-tubeless-specific Mavic Open Pro rims to get them seated. This is a wheelset I've had half a dozen tubeless tyres on over the last two years, so yes folks, the turkeyshoot that is tubeless tyre-rim compatibility continues.

Once mounted, they sealed up fine using Stan's, and didn't leak any.

They feel fast on the road, corner well and are pretty quiet for a treaded tyre, so no complaints there. If you need to transit on road to a trailhead you'll not feel let down by rolling resistance or handling.

> Buyer's Guide: 9 of the best tubeless tyres for winter

Testing in autumn, in Scotland, finding stretches of actually dry gravel proved a bit of a challenge. Cornering with no side knobs to speak of isn't overly inspiring, but on dry-ish clay/gravel they didn't let go except once on a very off-camber section, and I was able to hold it together without too much squealing.

Dry leaves foiled them on a 15 per cent pitch, the rear wheel spinning out where other gravel-orientated tyres have stayed stuck. I found them to be good enough on dry gravel attacks, but put even a thin layer of silt over the top and things get slippery really fast as the tread fills. (The GR2 might be a better bet for such conditions, full review to come.)

Control on fast descents is okay, with 35psi more than enough to hold the shape in corners and prevent any rim dings with 40mm of volume to play with, but again the lack of any decent edge means when you do spot a smoother section to regain control in, chances are if it's wet you could be up for a quick course in counter-steering.

Braking over loose rocks and slabs of granite was predictable, if not as confidence-inspiring as a grippier tyre would be.

I could have seen myself using the GR1s at the Dirty Reiver race, IF there wasn't a hint of rain forecast.

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The GR1 is definitely a tyre for drier, smoother gravel/road expeditions. It will handle flatter bridleways and towpaths just fine, but don't expect much grip on damp, grassy, leafy or silty surfaces – which is pretty much all of the UK for six months of the year.

Verdict

A fast tyre in the dry on the firm and dusty, but not in damper, less-gravelly conditions