Excuse the pun!
I've tried to make the most of the long evenings in the last couple of weeks so have explored a couple of the tributaries of the Thames.
First up was the Hogsmill; never heard of it before but it runs from Ewell to Kingston. Rode in reverse starting at the North end. It's impossible to join the route until Berrylands as much of the first section is a water treatment works. A bit haphazard after that especially getting over the A3 near Tolworth while it goes under. Not really a proper cyclepath from there until you go under the A240 but then it's a nice rural route all the way to where the Epsom bit branches off. A real gem in the form of a tunnel under the railway embankment with a bridge above the river before it all ends abruptly at the source and back onto a busy road.
Tonight, the Wandle. This starts looking promising but it's immediately buried by Wandsworth shopping complex eventually resurfacing off Garratt Lane. Eventually, it becomes NCR 20 and properly surfaced until Morden but a lot of road crossings to deal with. Lost it from there but eventually picked it up in Beddington. Much of the cycle route leaves the river which was not what I was there for. Shocking bit of uneven surfacing for much of it (where they've put the all weather surface almost straight onto the grass without enough foundation so it's subsided). Eventually got to Hackbridge where I took the Croydon arm. Again you have the choice of the opulent public park or the inferior cycle route through Beddington Park. It stops abruptly in Waddon Ponds slap next to the A23 which is the most unlikely start of a river.
Would like to ride them all eventually anyone got any experience of any others?
I meander down the Wandle a lot, it gets me home if not especially quickly), it's not always easy to follow. From Morden Park through to Beddington, it's mostly paths that thread around the edges of several housing estates (surfaces generally not so bad, there's a bit of gravel, and some bumpy tree roots – if you're expecting a European-style path you'll, of course, be disappointed, but it's doable on a road bike). It generally follows the river to Waddon Ponds then down the road past Wandle Park. After that it disappears under the Croydon (somewhere it meets the Caterham Bourne and a few other subterranean rivers that supply it). There's a fair amount of riverside wandering, judging by the number of midges I end up eating. If you make it as far as Croydon, treat yourself to a beer at Matthew's Yard which is handily located at the end before it pops out on Surrey Street behind the cinema.
I've walked the Hogsmill (and cycled a bit of it). Like most suburban rivers it comes and goes. You can follow the Deptford Creek/Quaggy/Poole down the Waterlink Way which runs from Greenwich down through Lewisham, Catford, Kent House, South Norwood, Croydon (and onwards all the way to Gatwick and beyond, but there are parts beyond New Addington where'd you need a tank to make progress). The river disappears after South Norwood Country Park where it mostly becomes a slog through suburban streets till the back end of Shirley and Addington Village and the peculiarity of New Addington and then you're out in the country. It's a reasonable cycle route, mostly paved, occasional suburban streets that take over after Cator Park.
You get snatches of Beverley Brook down near the A3/Worcester Park, but they're not worth the effort unless you like endless semi-deteched suburbia slashed through with arterial A-roads (actually this sums up most London rivers and to be honest, I'm a bit of a suburban explorer).
The River Crane/Hillingdon Trail runs down from the canal through Uxbridge and all the way down to the Thames (via the canal at the end). You get the delights of the edge of Heathrow's sprawl but occasional bursts of countryside.
Pymmes Brook runs from Cockfosters to the Lea, runs through several parks and bits of suburbia. Absents itself from Edmonton Green (probably for good reason) then reappears down to the Lea where you can follow the tow path down to Tottenham Hale (at which point I'm usually thirsty enough to visit Pressure Drop and Beavertown, you may note a theme here).