Just popping this up there with the new Spring. @Mlac Peek and I are there regularly. (Not quite as regularly as a few years ago) but there will usually be one of us there most mornings from about 6am to 7:10.
Anyone in the area looking for some morning riding please come out and join us. Pace on the river is usually around 33-36km/hr (Average). But feel free to come out and ride your own pace. It's a great place for morning rides, no cars, water views, Mt Fuji and Mt. Tsukuba on the horizon when the air isn't too thick.