Pearl Izumi has been making thermal clothing — most notably arm and leg warmers — for years now, and its wares have been well received. The P.R.O. Thermal bib short builds on that legacy and boast a new chamois to boot. If you like a thick chamois in fleecy shorts that aren't constrictive, you'll probably love this for cold-weather riding.
The fleece short feels very much like warmers on the legs — soft to the touch on the inside with mild compression. The thin mesh bib straps feel like they disappear when you're out on the bike – exactly the way you want straps to feel.
The short runs relatively large and fits long in the leg – the medium size has a 9in inseam, for example. When the object is to stay warm in conjunction with knee or leg warmers, a little extra length isn't a bad thing.
The new 4D chamois is a great step forward for Pearl. It features a smooth, single layer that contacts your skin over a heavily sculpted pad. While many of Pearl's other chamois pads — and those of other companies — have a segmented look, we appreciate the smooth design here.
Pearl Izumi's new 4D chamois
On our tester, the thickest part of the pad, designed for the sitbones fell slightly aft of where our sitbones contact the saddle. Still, the pad is quite comfortable, noticeably wicks well and, in the cold, it added a layer of warmth compared to other thermal bibs we tested.
The logos and a few details are rendered in a reflective element — always a good thing for cool-weather gear when lighting is often poor.
While Pearl suggests the thermal bib for a temperature range of 53 to 58˚F (11.5 to 14.5˚C), we were comfortable riding in it with leg warmers down to 40˚F (4.5˚C).
There are no traditional leg grippers, instead, Pearl uses a double thickness of the thermal material at the openings with little silicone dots for grip.
Be sure to consult Pearl's sizing chart before you buy, and if possible, try the P.R.O. Thermal bib short on before purchasing to check how the chamois placement works for you.