Arty
Well-Known Member
I installed a Sick Bike Jackshaft kit on my bike last summer, and after riding for a couple of weeks, found that the engine seemed to be twisting in the frame, causing poor chain alignment.
Upon close inspection, I found that amongst other things, the rear engine mount of the jackshaft kit seemed to have twisted out of shape, and was also not indexing onto the seat post tube as well as I'd have liked.
Anyway, to solve the issue, after straightening the jackshaft bracket, I built a stiffener to slide inside the jackshaft bracket that fits between it and the seat post tube. that extends far enough down to also straddle both jackshaft bearings. It's not real pretty, and there's a ton of MIG wire in it - but hey - it works.
The two holes just above the jackshaft bearing saddles are for a piece of ready rod that slips through the whole assembly after installation in the frame, with two nuts per side to box the whole thing for added rigidity.
I know this sounds a bit complicated, but anyone with a jackshaft kit will likely understand.
It's a bit on the heavy side, but in conjunction with an improved front mount, my engine is now rock solid in the frame.
Upon close inspection, I found that amongst other things, the rear engine mount of the jackshaft kit seemed to have twisted out of shape, and was also not indexing onto the seat post tube as well as I'd have liked.
Anyway, to solve the issue, after straightening the jackshaft bracket, I built a stiffener to slide inside the jackshaft bracket that fits between it and the seat post tube. that extends far enough down to also straddle both jackshaft bearings. It's not real pretty, and there's a ton of MIG wire in it - but hey - it works.
The two holes just above the jackshaft bearing saddles are for a piece of ready rod that slips through the whole assembly after installation in the frame, with two nuts per side to box the whole thing for added rigidity.
I know this sounds a bit complicated, but anyone with a jackshaft kit will likely understand.
It's a bit on the heavy side, but in conjunction with an improved front mount, my engine is now rock solid in the frame.