When we put together the DL Racing team, I knew we had to make some high end race equipment to give our riders every advantage possible. Early on, I went over to HED to ask for some guidance as to what was important and what wasn't from an aero perspective. Steve Hed was one of the most knowledgeable people on the planet when it came to aero design in cycling. Steve was also one of the most generous and excitable guys I have had the pleasure of knowing. HED was also in town, and less than a 15 minute drive from DLHQ
To give you some perspective on Steve, was always up for learning about what I was up to, giving me a tour of HED and talking about the machines and processes they had to make wheels. I grew to really like and respect the guy and his passing hit me hard as I was really just getting to know him.
Back to the speed suit. Wrinkles! it is all about wrinkles. Yes fabric, and seam design have some affect, but they are all thrown out the window if there are wrinkles! So se continued to adjust pattern pieces to eliminate wrinkles. All of our on model testing was done on a TT bike to allow the pattern makers to see how it was used and how it flexed in position with the pedal stroke. We went with a surged seam vs. a flat lock stitched seam because it is a more aero seam design.
We kept the sleeves long as fabric is more aero than skin (read this). The fabric we found was a french woven fabric (most fabrics you are used to are knit). This woven material is super light, tough, prints well and has a cooling effect on your skin. Tibot Pinot and Vincenzo Nibali both used this fabric in the 2014 tour on their TT suits.
The other key feature is the bottoms, Ian Stanford (national TT champion 2014 40-44 year old) helped after Steve's passing to ensure our design was as good if not better than what was existing on the market for 4-5x the cost. Chamois placement is often done poorly in TT suits. It needs to be forward as the TT position puts the rider on the nose of the saddle, and it also must stay put and not move around during hard efforts (not as easy as it sounds)