Assos often goes overboard with its marketing and terminology, but the fact is that the Swiss clothier's chamois construction and placement set the standard for what bib shorts – and bib tights – should be.
The LL.Uno_s5 bib tight is a luxurious, lightweight thermal piece with an excellent chamois pad with spot-on placement.
The bib tight uses a brushed thermal fabric called RX, which is similar to the Super Roubaix fabric that's familiar to many cyclists. The RX is relatively thin, but with good loft for insulation and great wicking. Compared to a standard, winter bib tight, the RX fabric feels almost sheer in how easily it moves, with great breathability. Although it's not designed for brutally cold or wet conditions, we were comfortable riding in the LL.Uno_s5 tight in sub-freezing temperatures as well as on moderately chilly days.
These bib tights are somewhat remarkable for their absence of ankle zippers, a fairly standard feature on bib tights these days. While this struck us as odd initially, the smooth lower legs are noticeably more comfortable than something with a zipper. (Think about it – have you ever referred to a zipper as 'comfortable'?!) The tradeoff is that you have to take an extra second to pull the elastic hem over your foot.
The wide, upper straps lay flat, and the fit is cut for the riding position, not standing straight up. Still, the overall fit is not constrictive, even when standing.
The marquee piece is the chamois pad and its dialed placement. A chamois can be described with whatever superlatives you want to throw at it, but if the placement is off then it doesn't matter. Assos chamois pads feature two layers: an uninterrupted soft layer against the skin, and shaped inserts underneath that support the sit bones with room between for relieving perennial pressure. With this FI.Uno_S5 chamois, the inserts sit exactly where needed.
Assos recently went to a waffle texture on the skin layer of the pad, which they claim regulates temperature better than a flat pad; we can't tell a difference temperature-wise, but the comfort is the same as on early Assos pads.
All in all, the LL.Uno_s5 is an incredibly comfortable piece for dry winter riding, to the point that it makes the prospect of riding in leg warmers and thermal bibs – with their multiple pieces, seams, grippers and zippers – a little disappointing. This is a pair of bib tights that you can wear for a five-hour ride, then come home and take a nap in. You've been warned.