I've decided to risk the saris bones 2 with mine. My ebike is also 17kg. So far have had it on the back 3 times for 20 miles, with most of that being 70-80 down the dual carriageway. So far no problems. the bike seems to move side to side a bit over the bumps, but I'm quite confident the bike the bike is secure. Will update if I get any problems, but so far so good.