Vests - or gilets - are a great bit of kit to have in your back pocket. While warming up they protect your core from the chill, being small enough to remove and stuff in a pocket once your muscles have started to pump out heat.
This excellent option from Sportful does all that, but it does it in the lightest and most packable way. In fact, once stuffed into a back pocket we find it too easy to forget it is there. More than once it went into the wash still secreted in a jersey after a long day in the saddle - forgotten after it had done its duty at the start of the ride and after a cafe stop.
The 7 denier ripstop fabric means it packs down to the size of a tennis ball and weighs a measly 40g (large size), but it still does the job perfectly. The wispy fabric is windproof with a DWR coating to shrug off showers, while mesh panels under the arms keep just enough air flowing to prevent sweat build up. Expensive, and we certainly wouldn't recommend it for the rough and tumble of mountain biking, but cutting edge technology.
