Shimano R315 shoes

Shimano's new top-end R315 road shoes come with a super-rigid carbon sole and feature Custom-Fit technology that ensures they're big on comfort.

The R315 takes over from the R310 as Shimano's flagship model, but unlike its predecessor it gets an upper that's made from Rovenica. This is an ultra-fine synthetic material - very supple stuff. It's strong and doesn't stretch to any noticeable degree, but it's very thin.

The straps are made of the same material, the two lower ones being simple hook and loop (Velcro-esque) fastenings with the broader upper strap using a clicky buckle. Shimano reckon that the low profile buckle design results in less drag than usual but, come on, it's not going to be a deal breaker, is it? More significant, all the straps are easy to adjust on the fly and you can replace that top one if you whack it in a crash.

You get lots of ventilation here including two cutaways in the sole and mesh above the toes, so sweaty vapour can escape easily enough to keep your toes all fresh and lovely. You might have trouble keeping your feet warm in these during the off-season due to all that air conditioning, but they're designed as race shoes - you can't have everything.

The sole is unidirectional carbon fibre in what Shimano call their Hollow Channel design. Essentially, that means it has a scooped out section to keep the weight down. It's absolutely solid despite its lack of weight; there's no flex whatsoever. Unlike some, the reinforced areas at the heel and toe are non-replaceable, but there's sufficient material here that you'll never wear through it as you waddle to and from your bike.

The carbon extends slightly around the sides at the heel to provide extra support and the heel cup itself holds your foot firmly in place. Shimano use a metal fibre in the heel lining too that stops your foot from lifting. It feels weird to the touch but it does work.

The soles are drilled for three-bolt cleats, by the way, which means they're compatible with Shimano's SPD-SL, Look Keo, Time road, Mavic...

As I said, the shoes feature shimano's Custom-Fit technology? Both the upper and the insole are mouldable. When you buy the shoes from one of the Custom-Fit stores //http://www.madison.co.uk/customfit///, the guys in the shop will heat them up and mould them to your feet. The uppers are moulded with the pressure of a vacuum bag - you bung your foot in there, the air is sucked out, and the shoe shapes around it. Once it cools down it stays that shape to provide a snug fit.

Shimano reckon the closer fit improves power transfer. Does it, though, if you have a decent fit to start with and your feet aren't moving around all over the place? Maybe, but if it does, it's marginal. It can make a difference to your comfort, though, by evening out pressure.

Speaking of comfort, these have felt great over the past few weeks. Stable, supportive and supple, they've been excellent for both quick blasts and all-dayers. It's worth bearing in mind, though, that these are quite wide across the toe box. That's great if you have a broad forefoot. If not, doing the Custom-Fit thing can draw them in a bit, as can tightening the lower closure strap... but only so much. If you're narrow across the toes, the R315 isn't the best choice for you.

Ah, the weight; I've not told you that yet. These are size 46s and they come in at 632g the pair (without cleats). That's pretty light, especially for something with a ratchet buckle. You can find lighter, but these are far from heavy.

Verdict

Comfortable custom-fit race shoes with a supple upper and a rigid carbon sole