Castelli Nanoflex Leg Warmers

Castelli's Nanoflex Leg Warmers are well designed and comfortable with the added bonus of being water repellent.

We've reviewed Nanoflex kneewarmers and armwarmers on road.cc in the past and we've been impressed.

The big selling point here is the water repellency of the Nanoflex. Castelli use their Thermoflex (a brush-backed Roubaix) fabric with the addition of "tiny silicone nanofilaments on the surface". This results in water beading up and rolling off.

Castelli don't claim that Nanoflex is completely waterproof. It'll keep road spray and showers out but harder rain does work through, especially through the bit at the front of your knee that you stretch repeatedly as you pedal. But the point is, these feel like any other leg warmers in terms of feel and breathability – like most, they're made from nylon and Lycra – so there's no down side to that extra water repellency.

How long does the Nanoflex keep doing its job? Well, I did a little test and found that the knee warmers I have from a couple of years ago that have been through the washing machine a zillion times weren't doing much in the way of keeping water out any more. Arm warmers from about a year ago that have been through the wash a couple of dozen times were still doing well.

I contacted Castelli's UK distributor, Saddleback, to find out if that was to be expected and they said: "Light ironing over the surface will rejuvenate the protection."

That's what I did and – hey presto! – it worked. I wouldn't say that the performance is right back to original levels, but it's not far off.

Nanoflex aside, these are good leg warmers in their own right, coming with just one flatlock stitched seam up the back, which I haven't found at all irritating. The elasticated gripper has silicone on the inside to hold it against your leg, and on the outside to keep it in place against your shorts. I've never had any trouble there. A YKK zip at the back makes getting them on and off easy, even over your shoes.

Castelli give a temperature range for every item of their clothing and we usually agree with them. In this case, they say 8-16°C. You could wear these when it's a little colder than that, but chances are that if it's that nippy there's no chance you'll want to remove your leg warmers mid-ride, so you might as well go for tights.

Verdict

Warm, comfortable leg warmers with the added bonus of being water repellent.