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When you're downshifting. Clutch in, shift to neutral, clutch out. This spins up the main shaft again so there is less wear on the synchro. Blip throttle, clutch in, shift into lower gear, clutch out. You can do this when upshifting too, but it takes extra time so I don't bother and you should be OK if you time it well enough. Fun fact, Steve McQueen double clutches all his upshifts and downshifts in the Bullitt chase scene.

bassmonster wrote:When you're downshifting. Clutch in, shift to neutral, clutch out. This spins up the main shaft again so there is less wear on the synchro. Blip throttle, clutch in, shift into lower gear, clutch out. You can do this when upshifting too, but it takes extra time so I don't bother and you should be OK if you time it well enough. Fun fact, Steve McQueen double clutches all his upshifts and downshifts in the Bullitt chase scene.

Hmm interesting indeed.
What you've described I know as double shuffling.
I got a truck license last year ("proper" trucks lol, not oversized utes), and despite double shuffling for many years, I wasn't allowed to double shuffle during the test. The theory being that todays modern manual boxes are stronger and the synchro can take it.

Double shuffling is a very handy technique.
Before synchro boxes, there were no synchros of course, and I know these as crash boxes.
The only way to change gears in these boxes is with double shuffling and getting the revs just right.
These boxes led to the old saying "if you can't find it, grind it".
Given the amount of times you can still hear people grinding gears, crash boxes still must be around huh

Grant Bunter wrote: Before synchro boxes, there were no synchros of course, and I know these as crash boxes.
The only way to change gears in these boxes is with double shuffling and getting the revs just right.
These boxes led to the old saying "if you can't find it, grind it".
Given the amount of times you can still hear people grinding gears, crash boxes still must be around huh

I usually use the throttle to float the gears, and then pull it out of gear, blip the throttle and put it in a lower gear (highway tractor-trailer/semi). Sometimes, I will use the clutch to get it out of gear, though.

Excellent Tom!
For me, it's mostly about having the engine and the box spinning at the same rate (in gear or out or on the way from one gear to another).
Everything seems much easier then...

When i downshift i blip the throttle to rev match engine and gearbox. Nothing special when upshifting. We do have some trucks at work that still required the dubble clutch technique.