The descent after a long climb comes up fast, and the Smith Payroll MIPS Aleck CS Helmet covers it with layered impact protection in a lightweight mountain bike helmet. Inside a lightweight in-mold shell, zonal Koroyd absorbs impact energy, and the MIPS liner reduces rotational forces in angled impacts. What Our Gearhead(R) Experts Are Saying:"On solo rides, I paired the helmet's crash sensor with the free app on my phone and kept the phone in my pack. After a hard impact, the sensor confirms my status and sends my GPS location to the contacts I chose."