Four years ago, after many years of research, we installed a Bionx system on our recumbent tandem. At first, we just ran into obstacles that we weighed, and when the company came out with a wider hub than 135 mm, we decided to give it a go. The drawbacks are there, of course. The system adds 16 lbs to the total weight of the tandem. We lost our Arai drum brake which we needed to scrub speed on downhills. While the regeneration mode gives you some braking, I believe it is not adequate and so now heavily rely on the rim brakes, front and rear. It is necessary to "feather" the brakes on and off as too much friction on the rim can blow a tire from over-heating. On the positive side, we love the set up and we are riding our tandem more than before since going electric. The system has worked flawlessly, we are still getting 70 km on a single charge using levels 1 and 2 and that's a heavy team (bike + two riders = 430 lbs.) The battery takes about 4-5 hours to fully charge even after many, many charging cycles. Bottom line is we're both happy and we'd do it again, although we're sorry to learn the company may fold. Mike