1. clutch in
2. shift to neutral
3. clutch out
4. clutch in
5. select gear
6. blip gas
7. clutch out
or
1. clutch in
2. change gear
3. blip gas
4. clutch out
Not to beat this subject to death and no disrespect intended, but both methods described are the same except for motions 2, 3 and 4 in the first group which aren't accomplishing anything.
Without raising the engine speed between 3 and 4, the input shaft/clutch rotates at the same speed of the engine which is invariably lower in rpm as the output shaft in the next lower gear. It'll work in a gearbox w/synchromesh, but it's not doubleclutching. Try it on a non-synchro gearbox and see if the above methods work. Got a tractor handy?
Or try downshifting into 1st gear at 10 mph using the various methods described in this thread. 1st gear in a 915 gearbox closely approximates a non-synchro-assisted gear.
Sherwood