bounce/jump pad question

[MonoXideAtWork]

I'm trying to create a jump pad for my latest map, and I can't seem to get it to function how I like.

I have a cylindrical brush textured with tools/trigger, and tied to a trigger_push.

The brush is the full height of the jump I'd like the player to make.
push direction is "up" and push force is 1000u/s
Technically, it works, but not how I expect it to. I would like it to function like the pads at the entrances to the bases in ff_aardvark, where you touch it and you're off. At the moment, it requires a jump to get going, like the fan shaft in ff_bases. Can anyone point me in the right direction? Thanks.