I’ve been meaning to sew up and experiment with a Body-Sock for quite some time (For those who do not know, a Body-Sock is a cloth attachment that covers the un-faired parts of the bike and rider to clean up the airflow). I finally had a chance to make one and tried it out on a 250km trip. below are my observations.
The biggest reason to implement a Body-Sock is for improved aerodynamics and efficiency and this idea was born out in my test. I found that the Electrom was between fifteen and thirty percent more efficient at speeds over 30 km/h when using the Body-Sock. It was especially impressive at the highest speeds. I found that I was consuming about 1000W to go 60 km/h with the Body-Sock, and without it, the same speed requires over 1500W. I have not yet done any control testing on the same track, but when I do I’ll post updates.
Effects of Cross-Winds
Of course the aerodynamic and thus energy saving advantages would be obvious, but I was more curious about what the down-side would be. My biggest concern was what the effects of cross-winds would be on a vehicle such as the Electrom when more surface area was added. I was pleasantly surprised to find that it was quite manageable; while there was a noticeable increase in the effects of strong cross-winds, it was well within my abilities to handle the Electrom. One of the interesting aspects of the Electrom is that it becomes more stable the faster you go. I expect that this is a result of the gyroscopic effect of the heavy wheels, but with the Body-Sock, the speed-stability effect was increased. I believe that this is because the faster the bike goes, the more it acts like a knife cutting through water, where the equal fluid pressure on each side keeps the knife moving in a straight line. I had the Electrom up to 65 km/h on the flat, and as fast as 85 km/h on some downhills and it just became more and more stable.
Large Vehicles Passing
I was also worried about how it would handle the backwash of large vehicles passing me on the highway. There was no noticeable change in this regard, The Electrom has always remained stable when large trucks pass and this did not change.
I didn’t make the the Body-Sock for additional weather protection, but on my initial test ride of 250 km, it did start to rain quite heavily at the end. Even thought the body sock is made of a non-waterproof lightweight fabric, it did a great job of keeping me dry. I probably wouldn’t use it for weather protection on short trips (see below) but for longer trips it would definitely be a benefit.
There’s no denying that the Body-Sock makes getting on and off the Electrom more of a chore. It also requires a bit of forethought to quickly get one’s feet down when coming to a stop. For this reason, I would only recommend the use of a Body-Sock for longer trips where the advantages would outweigh the dis-advantages.
The Body Sock is a worthy addition to the Electrom. It saves a significant amount of energy and provides additional weather protection. Because it is awkward to climb into, I would suggest that it only be used on longer trips. There are no plans to make a Body-Sock for sale, but once we have finalized the pattern, we may make a template available to those who wish to make their own. The use of the body sock does add to the complexity of operation, so we cannot suggest that anyone use one until they are very comfortable with their Electrom and, of course, use of a Body-Sock would be the rider’s choice and they assume all risks.