What is your idea of small jumps? And what year R. Some people call the 81 and 82 R the first generation, I personally believe the 81 is the first generation R as the 82 was different with the disc brake, but most people lump the 81 and 82 together because of the wide front tire. The 81 and 82 both will handle jumps just fine. The 83-84 had a little more power than the 81-82 and the frame was a little beefier, but they were a fine trike and you just can't replicate the personality the 81 and 82 R have with that wide tire, classic lines.
Nicholson 500x (Project)
Nicholson 185s
Nicholson 110 (That takes an atc70 tank)
Ascott 500 head/350x (Project)
Homebuilt Racer Chromoly Suspension 110 (Ragin Runt)
PK Racing Suspension 70
A+ Inc Suspension 70
AWS Aluminum 90 frame
Hi Performance ATC Suspension frame rd350
Hi Performance ATC Suspension frame 90