IRC Boken Plus gravel tyre 650B

IRC's Boken Plus multi-surface tyre is a lot more versatile than you might expect at first glance. It looks like it'd roll well on tarmac, and it does, but it's surprisingly capable on much rougher terrain too.

The Boken Plus is a semi-slick tyre, with a solid centre tread that gets increasingly open the further you move from the centre line. There's a herringbone section either side of the middle, and then two sections of blocks on the shoulder. The idea is that the middle section will roll well on smooth surfaces, and then the more open tread comes into play when the bike is cornering, and when the surface is uneven and the tyre deforms over obstacles. It's built around a tubeless-ready carcass.

> Buy these online here

I've used these tyres on a variety of rides, and I have to say I'm impressed with the levels of grip they offer. Most pertinently I completed a two-day bikepacking trip from Barnstaple back to Bath that included rough technical descents and climbs, graded gravel, woodland singletrack, grassy slogs over the moors and tarmac sections, in both wet and dry conditions. There's no one tyre that you'd say was perfect for all of that, but the Boken Plus rarely put a foot wrong.

It wasn't a surprise that the tarmac sections were a breeze: the unbroken centre strip makes them nice and quiet on the roads, which immediately makes you feel faster, but at cruising speeds they're also stable and predictable through the turns. They're reasonably heavy tyres, but if you're carrying gear for a two-dayer that's not an issue. On an unloaded bike they don't feel sluggish either.

More impressively, the Boken Plus rubber coped with loads of varied terrain with very little fuss. They're great on graded gravel, but they're also really good on steeper, rockier stuff. With the pressure reasonably low (I was mostly running around 35-40psi), once they start to deform over the surface of the trail they really bite, offering up much more grip than you'd imagine the design would provide. IRC says that it uses 'Ultra-Gummy Compound for Insane Bite', and the edge blocks are hollow so that they'll deform more for extra grip. It works: short of wet roots, where any tyre would struggle, I rarely wanted for grip.

Obviously, any tyre has its limits. These Boken Plus tyres struggled in a couple of situations. Where there was loose gravel on top of a hard surface, say a tarmac corner, there's not enough tread for the tyre to grip or enough roughness for it to deform, so they tend to marble across the surface. And on tightly cropped grassy descents you'll be doing a fair bit of skidding at the rear wheel, although there's enough grip to manage your speed.

The 47mm carcass gives plenty of air chamber, so you can run the pressures low without worrying about bashing your rims, especially when set up tubeless. I've taken them as low as 25psi (I'm 92kg) without any issues, and off-road grip gets even better although of course the road performance starts to suffer.

> Buyer’s Guide: 29 of the best gravel bike tyres

Talking of tubeless, they're excellent: they went up first time with a track pump (onto Hunt rims) and they hold air better than nearly any other tubeless tyre I've tried. Some of that weight is going into making sure that carcass is properly air tight. I didn't suffer any punctures that required any plugging in the 500km or so I've run these tyres for, either.

At £55 an end these aren't the cheapest multi-surface tyre you can get, but they're a similar price to some tyres that I'd consider to be a direct competitor, such as the WTB Byway. The excellent Schwalbe G-One Allround is a bit cheaper, and in fact I stripped a pair of large-chamber G-Ones off my gravel bike to fit this Boken Plus rubber. Back to back I prefer the IRC tyres: they hold air better, they're quieter on the road and they're as good if not better on the rough stuff. As an all-purpose tyre, they're really good.

Verdict

Really good mixed-surface tyre that's a lot better off road than its profile would suggest