How do I shift without the thump?
You should wait until the point where you are no longer pressed into the back of your seat to let the clutch out on your second gear shift. As to the actual application of this technique:
1. You are in first gear, taking it to your favorite shift RPM.
2. Once you reach this RPM, let off the gas pedal and depress the clutch.
3. Shift into second. (Items 2 & 3 can be done quickly)
4. "The wait". Judge it based on your body's movement. Visualize your pelvis as the axis....when the rearward pressure of acceleration leaves your body and you feel as if you can naturally lean forward at the waist.....this is the shift point.
5. Release the clutch.
This is a shifting technique that requires some practice due to variances from car to car. Yes, it's slower, but better for your rear differential and transmission in the long run.
I think this could use some editing.
The imput shaft when disconnected from the driveline and engine rotates at about the same speed as the flywheel.
So if you want a smooth shift all you need to do is put light pressure on the gear shift untill it 'falls' into gear then lift up the clutch at a quick pace (less than a second) with no jerk or clunk.
For example, you're in second gear. For a smooth shift put your foot on the clutch and take the car out of gear. Take the gear lever, don't jam it into the next gate, and put light pressure to get it into 3rd. When the revs match the shifter will seem to almost pull itself into gear. At that time you can lift your foot off the clutch quickly.
Much easier than waiting for that point when the accleration of the car has slowed.