NOT NORMAL!
What we think of as 'sweet handling' is fairly light control forces, BUT NOT negative stick force gradient.
If you have to apply forward pressure to keep an airplane from slowing down, ESPECIALLY in a elevated-g situation, then something is not right and it should be fixed. In an elevated-g situation, this could be really dangerous-- the airplane should unload itself if you release the stick, not pull harder making more g's.
Several factors, as mentioned here, can cause negative stick-force gradient, but if an RV-6 is built right and within c.g., it will not do this. This is not normal.
Elevator trailing edge radius can cause vague handling - a tendancy to not want to trim, but to sit slightly off trim to one side or the other (meaning slightly nose up or slightly nose down 'out-of-trim') and it may kind of snatch - abrupt change in force. But I don't think it can cause a consistent negative stick force gradient. There are 3 things that can. One is reverse camber in the stabilizer/elevator. Not likely in RV's, the tail is symmetrical, and it would be hard to screw that up with the pre-punch kits. Depending on how the trailing edge bend is done, it may be possible for the upper surface of the elevator to be more flat, and the lower surface to be slightly bowed or curved. This would cause the problem.
One is relative incidence between the wing and tail.
The third is c.g..
Bob weights and springs are not very satisfying ways to fix it. If you can not find the cause, you can install a fixed tab on the trailing edge of each elevator, about 1.5" by 8", and bend it down 10 degrees. This will fix it. But try to find out what is not normal about the wing and tail rigging and the c.g. first.
Tony,
It looks like all of the guys replying here are experienced RV pilots. Perhaps a perspective from someone who isn't will help.
What you describe was my overwhelming impression when I was taken for a ride in an RV-6. It took me many months to get over this "disappointment" before I purchased a second hand tail kit. The aeroplane I flew is very similar to yours except it has a metal propeller.
What I have noticed is that many owners describe this characteristic as "sweet handling" or "responsive" rather than "neutral stability". I have concluded that you just have to learn to live with it (or even enjoy it) in order to experience the many other great features the RV6 has.
The owner of the RV6 I flew and I have discussed this at length and his experience is exactly as you describe. Something that he has noted that others haven't brought up here is that on the RV6 the whole control shaft set up is hinged off the back of the spar and the effect of it is to over-balance the elevators. i.e. you set them up with 100% balance without the controls connected and once you connect the elevators, the effect of the "falling" control shaft is to move the elevators up. As you load the aeroplane with "g" the effect is magnified providing an additional up-elevator input. When I was flying the aeroplane around in a steep turn I was actually holding a slight forward pressure, yet we are used to holding (in some aircraft considerable) back pressure in a steep turn. This builder has suggested putting a "donger" weight in the control circuit to counteract this. This is not an unknown design feature in some aircraft. Other aircraft use springs to either cure or prevent this occurring or to generate a particular control force gradient. Even the slow Super Cub has a spring in the elevator circuit to help with trimming and many of the experimental Cub guys have either experimented with this or added springs to deal with undesirable control effects.
Over to you,
Andrew.