Santini have come up with a solution; the BCool Mig 3 bib shorts still hold the virtues of a traditional bib short in terms of comfort and design, however the bibs have been made as minimalist as possible to avoid the insulating effect that the bib material has on the body. The shorts have also been modified in other ways to increase comfort in extra warm conditions. The bibs are not cheap, retailing around £120 in most online stores, but I can safely say they are one of the most comfortable sets of shorts I have ever worn...
Starting with the innovative bib design... the bibs on the BCool shorts may be better described as braces in my mind; they are narrow elasticated mesh straps that start from low down on the waist, rise over the shoulders and then finish low down on the back. The braces are very effective at reducing the "sweaty back effect" that is often encountered with normal bibs, and they also dry out much quicker than normal material because of their lighter weight design.
It's not just the bibs that have been tailored to the heat though, the whole design of the shorts has evolved to the challenge. The material is far thinner than most; around the lower back and kidneys there is a mesh Lycra used to help ventilation (see large photo below). Then on the leg grippers a wafer thin stretch material is used; this is by far the most comfortable leg gripper that I have used, the effectively wide area that grips your leg means it stays firmly in place, without being overly tight or restrictive.
The seat pad is one of the defining factors in a pair of bib shorts. The Mig 3 in the BCool's name refers to the innovative chamois that Santini use in these top of the range shorts. I've worn a lot of pairs of shorts, and one thing that seems to define the comfort is getting the size of the pad right; too small and there is not enough padding, and you may actually end up sitting on the stitching around the edge of the pad; an uncomfortable experience! The other extreme is that the pad is too large and uncomfortable because if covers more than the area of the saddle, creating unnecessary friction. The Mig3 pad seems to offer a very admirable solution. The pad itself is composed of a padded foam central area, which is seamlessly attached to a large white flannel-like material. The composition means that the wide flannel material means stitching is well away from the sensitive areas, whilst the central padded core provides the much needed cushion.
Padding is not overly generous on the pads, but it is placed where it matters; and it is ribbed to allow added movement. The design fits in well with the warm weather orientation; reducing unnecessary material that may cause excess heat built up and moisture retention. Overall, a pretty impressive bit of padding!
Taking a complete overview of the shorts, the £120 price tag suddenly seems rather reasonable. These shorts are both incredibly comfortable in the hot weather, and very well made. They have a pad that works well, and they look pretty classy too; especially in the neon yellow that I have (they also come in red and blue). If you are planning on doing some serious hot weather cycling this summer, then I would definitely consider adding these to your shopping list!
N.B. Santini clothing tends to come up a little on the small size; especially if you are quite tall. I usually wear a medium size in most clothing brands, but wear a large in Santini. Check the size chart carefully.
Santini Shorts on Wiggle Bike Shop (Link)