dolphin1986 New Shifter Kit/Motorized Bike Jackshaft Kit - 66/80CC Gas Motorized Bicycle

I had to drill out the holes on both mounting plates, because the short chain from the engine to the jackshaft was so tight it wouldn’t even move. And the sprockets are too thick to use a mtb chain you need a bmx bike chain. Also the bolts they included to mount the side plates were too short. And the one way bearing for the crank gave out the first time I tried to ride it. If I could give negative stars I would.

Unless your willing to do some heavy fabrication this will not work unless you get lucky mine came with missing parts and the chain was too short and some parts wouldn’t fit so I had to grind some stuff and it still didn’t work

Takes a lot of modification i recommend files and hardware 4 flange bolts M6-1.0×35mm, 2 socket cap screws M6-1.0×35, and thread lock also you might hav to make a chain tensioner

I ended up having to replace several bolts and nuts as they stripped easily. A few bolts were missing. I ended up buying this as it was cheaper than the other kits. If you're using on a mountain bike, you will need to replace that bicycle chain with a wider bmx chain. The kit will require lots of modifications to work, which may include modifying the bike a bit itself.

Shifter kit isn't bad, but it takes modifying for it to work.

These thongs are awesome. You gotta figure it out yourself which sucks, but once you get it going its awesome. So much more power. Now instead of one gear i got 7. Also takes a while to fet it just right. And if you plan to put one on a fat bike your gunna need a longer shaft and different bearings.