Bontrager R4 320 Clincher Tyre

Nothing quite gives the pro look like some tan-wall tubulars on your race bike. If you're not into your tubulars, then the Bontrager R4 320 is about as near as you'll get in clincher form, with near-tubular levels of suppleness and grip.

The R4 320 shares much of its construction with a tubular: its 320TPI (threads per inch) polyamide-reinforced polycotton casing is the same as Bontrager's R4 race tubular, and the 60a durometer tread is glued on in the same way. Instead of sewing it up with a tube inside, you get a Kevlar bead for your 700C wheels.

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The R4 320s arrive completely flat, because that's how they're produced, rather than moulded like a vulcanised tyre. That makes fitting them for the first time a bit of a faff, although not as much as some other open tubulars I've tried, the Challenge Paris-Roubaix being a notable example. Once they're on and inflated they start to take on a bit of shape, so refitting them the next time isn't as hard.

Swapping to these tyres from a decent set of 25mm vulcanised tyres made a noticeable difference to the feel of the bike. They really float, these R4s. The supple case doesn't seem to be overly affected by the fact that Bontrager have sensibly added a Hard Case Lite puncture strip under the tread, and it soaks up road chatter brilliantly. It's like knocking 10psi out of your tyres in terms of feel. The levels of grip are excellent from the rough-slick tread, giving tons of confidence when you're leaning into a fast corner.

If you're looking for a 23mm then you're out of luck: Bontrager only do the R4 320 in a 25mm. At 250g per end they're hardly heavy, although there are lighter 25mm race tyres out there. All the pros use 25mm these days, anyway. Join the revolution.

Puncture protection appears to be anecdotally okay, in that I've not managed to flat either of these tyres yet. The puncture strip will help there, although the sidewalls are pretty vulnerable to thorns and such. They're not Gatorskins, obviously. But they're better than some race-orientated rubber.

Mostly I've used these for racing and dry, sunny good-bike runs: that's what I reckon they're ideal for. Grip in the wet is very good too, mind. As regards longevity, the polycotton carcass will degrade a bit more quickly than vulcanised rubber, and the tread is thinner than a moulded tyre too, and fairly soft. So realistically you'll not get many seasons out of a set of these, and at £54.99 each they're far from cheap. But if you want some lovely tyres for racing, which look good and perform superbly, then these are some. It's up to you whether they're worth the money. For the right kind of usage, I think they are.

Verdict

Super-supple race tyre with great feel and grip