This new lid may be a tad pricey, but for long, hot races it could be well worth splashing out. The emphasis is on low weight (250g all-in for a small or medium) and keeping you cool.
It’s made with an Integrated Composite Exoskeleton (ICE), which is a super-light plastic outer that directs air over your head to keep you cool.
Inside the helmet, instead of soft cloth padding, you get pads of gel that are designed to stay cool against your head, mould to your head’s shape, dispel sweat and minimise the helmet’s contact with you so it's as breathable as possible.
Other features (such as the adjustable fit band and light Kevlar strap) are more standard, and as good as you’d expect on a top-end helmet.
We tested the Sine-Thesis on several hot rides and found it really lived up to its claims: you’ll stay cool even when standing still with the sun beating down on you, and thanks to the gel instead of fabric padding, it’s a less sweaty choice.
The only problem we had with the Sine-Thesis was that one of our gel spots (which are removable) went astray after the first ride.