Terracycle/OHPV Coastdown Test 2005

On a beautiful September day, a bunch of folks from the OHPV joined the Terracycle crew for some coastdown testing of tailsocks. The object wasn't to get comparisons between different bikes, just to see if a tailsock could add speed under controlled conditions. So, we gathered a bunch of bikes at the top of a big hill on Highway 224 east of Estacada and used the bikes' computers to measure their top speed when coasting. Then we carried the bikes to the top of the hill, added tailsocks, and repeated the process. In the end, the tailsocks added 2 to 4 mph of top speed.

There were 7 bikes that were run in directly comparable configurations (sock on/sock off, everything else the same). For the sock off runs, the speeds averaged to 39.67mph. With the socks on, the average was 42.00mph. For individual bikes, the improvements ranged from 1.23 to 3.83mph.