BentMikey said:
Bryce, where in the lane would you cycle through an average junction?
What about through a pinch point, say where there is a pedestrian island?
What about along a longer stretch of wide road where there is plenty of room for motor vehicles to overtake?
What about a longer stretch of narrow road, where a motor vehicle can't overtake you without using the oncoming lane?
All quiet, Bryce?
Yes as I think I risk repeating myself ad nauseam and the thread has effectively been hijacked (apologies to OP) but my point again is I don't believe cyclists should act as road policemen - we shouldn't try to control the traffic behind us by slowing it down unless it's necessary and our motive is clear to drivers behind us - i.e. we are turning right or there is obvious danger ahead. I wouldn't expect a Fiat Panda to hog the outside lane of a motorway at 40mph because its driver feels unsafe being passed at speed. If I was behind said Panda, I wouldn't know why the driver was doing this and this might cause me to become frustrated and act impatiently. Same logic applies to cyclicts adopting 'primary' position without clear motive and for longer than necessary.
Prime example of this is Magna's vid where he adopts 'primary' before a pinch point and is overtaken dangerously by an impatient taxi driver. Vid has been analysed/ argued and each to their own again but I would have let the taxi past - even if it meant me free-wheeling or braking to let him through. Just not worth winding up the driver of a big lump of heavy metal IMO.
But to answer all your questions, my riding position would depend on a variety of other variables - weather, light, type of car behind me, driver's behaviour, my speed, incline etc. But normally I'd be ~75-100cms out from the kerb/ near-side danger spots. For the 4th scenario, I wouldn't be in primary as I'd place trust in the driver behind me. If it was a winding, single-lane road, then I might behave differently - either slow down/ pull in or pull out round the corners.