At road.cc every product is thoroughly tested for as long as it takes to get a proper insight into how well it works. Our reviewers are experienced cyclists that we trust to be objective. While we strive to ensure that opinions expressed are backed up by facts, reviews are by their nature an informed opinion, not a definitive verdict. We don't intentionally try to break anything (except locks) but we do try to look for weak points in any design. The overall score is not just an average of the other scores: it reflects both a product's function and value – with value determined by how a product compares with items of similar spec, quality, and price.What the road.cc scores mean
Good scores are more common than bad, because fortunately good products are more common than bad.
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.
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.
Super-supple race tyre with great feel and grip
If you're thinking of buying this product using a cashback deal why not use the road.cc Top Cashback page and get some top cashback while helping to support your favourite independent cycling website
Make and model: Bontrager R4 320 Road Tyre
Size tested: 700 x 25
Tell us what the product is for, and who it's aimed at. What do the manufacturers say about it? How does that compare to your own feelings about it?
Bontrager say: 'The R4 clincher gives unequalled road feel and racing performance in anextremely durable handbuilt tire thanks to Hard-Case Lite protection.'
Tell us some more about the technical aspects of the product?
Lightweight 320 TPI hand-built clincher
Excellent for road and criterium racing
Super supple polyamide synthetic fiber reinforcement for added casing strength
Hard-Case Lite has Lightweight sub-tread material protecting against punctures
Beautifully-made tyres, these.
Supple with excellent grip and road feel, great for racing and Sunday best.
They won't last as long as a full-vulcanised tyre, puncture protection is okay.
Light for a 25mm racing tyre, not the lightest.
Super supple feel. About as good as it gets without going to 28s.
They're not cheap, no. That doesn't necessarily mean they're terrible value though. You get what you pay for here.
Tell us how the product performed overall when used for its designed purpose
These are excellent racing tyres.
Tell us what you particularly liked about the product
Supple, grippy, well made, good looking.
Tell us what you particularly disliked about the product
A bit pricey.
Did you enjoy using the product? Yes
Would you consider buying the product? Yes
Would you recommend the product to a friend? Yes
Use this box to explain your score
If you're prepared to throw the money at them for a fairly limited range of uses, then these are super. Not for everyone.
Age: 42 Height: 189cm Weight: 91kg
I usually ride: whatever I'm testing... My best bike is: Kinesis Tripster ATR
I've been riding for: Over 20 years I ride: Every day I would class myself as: Experienced
I regularly do the following types of riding: road racing, commuting, club rides, sportives, general fitness riding, fixed/singlespeed, mountain biking, Mountain Bike Bog Snorkelling, track