Secondly, there are three key routes IMO: CS3 (the East-West Superhighway), CS6 (the North-South one) and the north side of London Cycle Network Route 0 (the old Seven Stations Link, not often signposted as that: I think it's usually "Paddington", "King's Cross" or "The City" on the signs). All of these are written in terms of how to get to those - then you could travel along them to get to your other station. Shortcuts are sometimes possible but IMO many are less nice and you're on your own! CS6 crosses CS3 at the north end of Blackfriars Bridge and LCN 0 at the Judd Street / Tavistock Place junction. CS3 and LCN 0 almost meet at Paddington.
Now how to get to/from each station:
- Blackfriars is just across the road from the main CS6/CS3 junction. If you exit the station through the new glass northwest exit, there's a cycle lane by the kerb which uses a cycle-only crossing just before the bridge to join CS6 or use the ramps down to CS3. I think CS3 eastbound be reached more quickly by taking Blackfriars Passage down and jumping the low kerbed central reservation to turn right, then left onto CS3, but I've not tried it lately. It may have been formalised - or blocked off completely!
- Cannon Street is just north of CS3. Turn right out of the station front, turn right onto Bush Hill, then left onto Gophir Lane and right onto Suffolk Lane down to CS3. Going to the station, turn off CS3 Upper Thames Street onto Suffolk Lane just east of the railway bridge, then left onto Gophir Lane and right onto Bush Hill. Station is just to the left at the top.
- Charing Cross is also just north of CS3: exit the station front, turn left and take the first left onto Craven Street, which merges into Northumberland Avenue and CS3 is ahead at its end. To get to it, turn off CS3 Embankment onto Northumberland Avenue just south/west of the railway bridge, then right onto Embankment Place under the railway, follow it round left into Villiers St, then the station is at the top end on the left.
- Euston is north of LCN0: exit the station front, head right and join Melton Road heading south, cross Euston Road into Gordon Street, and LCN0 is just after Gordon Square. To go to it, turn off Tavistock Place onto the west side of Gordon Square, cross Euston Road into Melton Street, then stop at the zebra crossing just after the underground car park entrance and use that to get to the station. There is a shorter way to St Pancras and King's Cross without going south to LCN0 - see the post below.
- Fenchurch Street is 200m north of CS3. Mark Lane connects the Hung Drawn and Quartered pub on CS3 directly to the west edge of Fenchurch Place in front of the station (turn left as you exit the station front).
- King's Cross is 200m NE of CS6. Either push/ride through/past St Pancras or, if going to CS6, ride forwards from the station into pretty much any side road across Euston Road and keep heading forwards until you reach CS6 at Tavistock Place or Sidmouth Street: if you do this, turn left to head south towards CS3 or right to meet LCN0 at Judd Street. To get to King's Cross, follow CS6 to the east side of St Pancras, then push through or ride past St Pancras to its west side.
- Liverpool Street is 800m north of CS3: exit the station front, turn right, then turn left onto Old Broad Street, keep going forwards across at least two sets of traffic lights, straight ahead across Bank junction, then left after some ornamental ponds onto a paved street (Queen Street, Quietway 11) and CS3 crosses you at the foot of the hill. To get to it, turn off CS3 Upper Thames Street onto Quietway 11 Queen Street, then turn right onto Queen Victoria Street by the "forgotten streams" ponds on the right (where the street changes back from paving to tarmac), continue straight ahead across Bank junction, fork left into Old Broad Street at the next set of lights and the station is eventually ahead on the right just after its underground station.
- London Bridge is 400m south of CS3: exit the station onto Tooley Street, turn left, then onto Duke Street Hill, turn right at the traffic lights onto London Bridge, then until Arthur Street is unblocked again, turn left at the lights onto Cannon Street, then third(?) left onto Bush Lane, left into Gophir Lane and right into Suffolk Lane and CS3 is ahead. Going to it, turn off CS3 Lower Thames Street onto Fish Street Hill, follow it left into Monument Street, then left onto London Bridge, left after the bridge into Duke Street Hill, straight on into Tooley Street and the station is on the right.
- Marylebone is 400m north of LCN0, but it's another fiddly one: exit through the station arch, turn right onto the road, left at the end onto Harewood Avenue, then go straight across Marylebone Road at the lights to join a cycle track on the far left corner that turns immediately left and enables access to Wyndham Street, then turn right at its end, left onto Seymour Place at the next crossroads and LCN0 is Crawford Road at the next crossroads. To go to the station is simpler: turn from Crawford Road onto Seymour Place, cross Marylebone Road at the lights into Lisson Grove, then next right into Harewood Row and the station is ahead.
- Moorgate - 800m north of CS3. Exit the station onto Moorfields (not Moorgate) and head north (the southern end is currently blocked by Crossrail anyway), turn left onto Ropemaker Street, then at the end turn left onto Q11. When going to the station, turn onto Queen Street, follow Quietway 11 to Moor Lane, then turn right after Pham Sushi and The Heron into Ropemaker Street, then right into Moorfields. As others point out, only folding bikes can be taken from this station at any time.
- Paddington is on LCN0 and 200m NE of CS3. To go to CS3, exit the station front arch, turn right onto Praed Street, keep going straight and turn left onto CS3 when you reach it. Take the lane on busy Craven Road / Praed Street. To reach it from CS3 westbound, turn left off Westbourne Terrace at the no-right-turn crossroads with Craven Road (where the cycle track ends in early 2019) and make a U-turn into the bike box and when lights turn green continue straight across (a hook turn - a move cars can't easily make) and Paddington is ahead on the left.
- St Pancras is on CS6, which runs along Midland Road and Judd Street along the west side of the station.
- Victoria is only 500m south of CS3 but awful IMO - best of a bad bunch is probably to exit the station front and push ahead right along Victoria Street towards John Lewis's Head Office. Ride along the street either side of it (the right one is smaller but involves a paved stealth road past the front of the cathedral), then turn left into Palace Street, take the next possible right, left at the end, then right at the lights at the end to rejoin the small section of protected track to the junction with CS3. Take the lane pretty much all the time... At least it's simpler in the other direction: at the west end of Birdcage Walk, cross the road to a small section of protected cycle lane, continue straight on across the lights and keep going straight ahead on some pretty minimal cycling infrastructure (bus lanes and bike boxes) and the station is just off to the left - if you continue past the Grosvenor Hotel, there is step-free access from the street.
- Waterloo is 700m west of CS6 or 600m east of CS3. Exit the station front, turn left, cross into Sutton Walk, turn right at the end onto NCN 4 Belvedere Road and then CS6 is at the end of Upper Ground - it's difficult to miss. Alternatively, NCN 4 Belvedere Road in the opposite direction and then Westminster Bridge connects to CS3 by Parliament which is better for Victoria, Paddington and maybe Marylebone. To get to Waterloo easily, turn off CS6 at the south side of Blackfriars Bridge onto NCN 4 Upper Ground, then after a while, turn left onto Concert Hall Approach, fork right onto Sutton Walk and the station is ahead after a crossing.
OK, so what have I misremembered or what's changed since I last used one?