Islabikes Greim Pro Cyclo-cross tyre

The Islabikes Greim Pro Cyclo-cross tyre is an excellent clincher model for muddy race courses and also well behaved enough for more mixed terrain should conditions vary between the tapes or you want to venture further. More importantly, it comes in smaller diameter sizes for future champions.

Islabikes' entire raison d'être has been to give children a better experience of cycling, designing bikes that are light and fun to ride and making sure they have components like handlebars, stems, brake levers and cranks all proportionally sized to fit smaller body parts. But one thing that's been missing from that list is tyres, and especially grippy tyres for people on smaller wheeled bikes who might want to give cyclo-cross a go.

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Turn up at any CX race and you'll see a massive and heart-warming increase in the number of kids haring around in the slop, and Islabikes wanted to develop a performance-orientated cyclo-cross tyre that would complement both its Luath cyclo-cross range and the muddy conditions most commonly found in a UK 'cross race. But although the resulting Greim Pro CX tyre was primarily designed for 24 and 26in wheel sizes to suit juniors, thankfully there's a 700C version for grown-up cyclo-crossers too.

When it comes to cyclo-cross tyres, Islabikes should know what it's doing. Company founder Isla Rowntree has a long and successful history in the sport, becoming British National Cyclocross champion a handful of times and winning the Three Peaks Cyclo-Cross race twice. So hopefully some of that experience has rubbed off onto the tyres.

The Greim Cyclo-cross tyre is available in two versions, the standard model that has a wire bead and a Kevlar puncture protection strip for £19.99, or the Pro on test here that costs more but comes with a 185 TPI (threads per inch) casing on a folding Kevlar bead, and, more importantly, has amber sidewalls for that pro look.

Actual weights of the pair of review tyres was 328g and 334g, a little over the published 320g number.

The Greim Pro is intended as a lightweight cyclo-cross racing tyre and as kids (and a lot of adults, it has to be said) aren't likely to have access to a vast library of variously treaded tyres for different conditions, Islabikes has concentrated on designing a tyre that has a performance bias in the most likely CX race scenario of mud. The resulting tread pattern is reminiscent of a few other race tyres designed for sloppy conditions, which is no bad thing, with the Greim's tread being made up of a series of L-shaped lumps of rubber, or Tetris blocks if you wish.

A line of that tread runs down the centre of the tyre with the long arm of alternating short-and-fat and tall-and-thin Ls forming kind of a broken angled central line, which means that the Greim Pro runs pretty swiftly on harder surfaces for a mud-based tyre. Either side of that, smaller squat L shapes angled sideways provide grip for power, with the largest blocks on the tyre saved for the very edges to give sideways traction through corners and those nice off-camber cross course sections.

The Greim is also designed to be run rotationally; for the road Islabikes suggests both tyres are run the same way, while for riding off-road the rear tyre should be reversed.

It's not often you stick on a new pair of tyres and within three pedal strokes down the road think 'wow, these are nice', but that's exactly what happened on the Greim Pros. They felt instantly fast and amazingly smooth and supple, and this was just on the tarmac down the road on the way to the dirt, where things got even better.

Unlike some tyres designed primarily for muddy conditions, the Greim Pro also works well in firmer, more hardpacked conditions, where it doesn't ever feel like it's floating uncontrollably underneath you on squirmy rubber and you don't have to tip-toe round corners on fidgety tread. And if you should encounter any tarmac, be that in the finishing sprint or in between off-road sections on a muck-about ride, it's not a noticeably draggy tyre for one with such an open tread pattern.

But it's in the sort of clart that usually frequents a cyclo-cross course that the Greim Pro really shines. The grip you get in sludge that other tyres just give up on is the best I've experienced in a clincher tyre, and thanks to the deep tread and large gaps between the lugs, even when the tyre looks like it's clogged with mud there's still grip to be found.

Those fat side lugs add an enormous amount of confidence both when cornering and on anything off-camber, and if the Greim does start to drift out it doesn't break away without warning, it's entirely predictable and easy to flick back under control. Well, most of the time. It makes riding in impossible mud fun again.

The 185 TPI sidewalls are a somewhat higher thread count than your average cyclo-cross clincher tyre, more than some similarly performance-orientated ones as well, and it's very noticeable, leading to an incredibly supple and comfortable ride, giving the softest of whispers of what it's like to ride a tubular tyre. The Pros are so lithe that you might need to put a little more air pressure in than normal, if you'll be bouncing over roots and bumpier terrain and don't want to bottom out the tyre on the rim and risk a pinch puncture. But even with that extra PSI they still feel pliable and grippy, and deftly conform to whatever you're rolling over pretty tenaciously.

The only downside to the Greim tyres is that their open and mud-friendly tread design makes them particularly susceptible to thorns or other types of piercings. A trait common to comparably spacious treaded tyres, it has to be said. This isn't necessarily going to be much of a problem if you're using them for racing only, but if you like to play out on your cyclo-cross in mud away from the race tapes then be aware of nature fighting back.

> How to avoid a puncture

If you're the sort of person who just uses their cross bike for general mixed terrain riding and playing about, then the cheaper standard version of the tyre that comes with a Kevlar anti-puncture protection strip might be a better bet. You'll lose those lovely supple amber walls, though.

Verdict

Excellent race-ready CX tyre that grips well in sticky/sloppy conditions yet isn't a handful on firmer terrain, with a wonderfully supple ride