Tell me about it. It would be nice to have a clear enough section of road to manage it for 5 miles in a single stretch, but that's not likely to happen in London. So I end up getting my speed up, cruising for a while, then having to stop for traffic lights (or some idiot reversing into the road, as happened today), then getting my speed back up again. That said at least it's an addiction that makes me healthier, unlike my passion for cake which got me into the Clydes area in the first place...

I've managed 100km in 5 hours but that's a far less impressive average speed, even though it included a brief cafe stop at the halfway point.