Now it works and why it didn't! [Flight starts at 4:10] ... https://www.youtube.com/watch?v=LHZI1W5zn20

Replacing the chainwheel. As mentioned in the video, adjusting the position of the EBB to move the crankshaft forward will mean you need to re-position the chain guard. To do this requires you to remove the cranks and loosen the drive-side (right) BB cup. The following describes what I did to achieve this. I have no qualifications in bike maintenance so if you are in any doubt, take it to a bike shop! The left-hand crank comes off with an 8mm allen wrench (normal thread, so anti-clockwise to loosen), then you just slide out the right-hand crank with the crankshaft. (There is a large thin shim on the left side, so take care it doesn't fall off when you remove the crankshaft.) To undo the BB cup you need a SRAM-compatible BB wrench. This one from Halfords will do: http://www.halfords.com/cycling/bike-maintenance/bike-tools/bikehut-external-bottom-bracket-tool, although ideally you will get a socket-style one that can be used with a long torque wrench. The BB cup will be very tight (34-40 Nm) and with the Halfords wrench you may need to hit it with a hammer to loosen it. THE DRIVE-SIDE BB CUP HAS A LEFT-HAND THREAD. This means you need to turn it CLOCKWISE to loosen and anti-clockwise to re-tighten. ... https://www.youtube.com/watch?v=JZ9q1OxtgKc