I just got a new style frame db30 and put on the jackshaft kit from promod. I really like it. I am a 230lb rider and the jackshaft provides quicker takeoffs and easy hill climbs even on grass. I rarely have to put my feet down now. I also bent my handlebars foward a little with a 3/4 in electricians pipe bender to give a little more room like the older db30 model. The install was easy. The hardest part was getting the clutch off. I heated the tip right near the nut with a torch and tapped it with a rubber malletand it slid right off. Promod provided some additional tips to help you. I may end up eventually going with the 4hp lifan motor, new clutch and modify my current jackshaft down the road. For right now the 2.8hp with the promod jackshaft suits me fine.