Not by one of these.... but by this geographical feature. I've ridden through this a couple of times a month for the past 5 years with no problems, but today it had a special surprise. Normally the surface is just concrete with a little bit of chalk silt if the flow is high enough. But since my last visit some algae's finally managed to get hold and made the surface like ice. Bike ok, newish and not cheapish pair of Gore trousers with a big rip, Ortleib pannier scuffed but not holed (good news, as it took a bit of a trip downstream with my laptop). Scabby hip (would include photo but NWS) sore wrist and another reason for my trashed left shoulder to stop working. Apart from the accident, have a look down the road across the River Arle, its a very pretty commute.