UAUS Black Jackshaft Kit Chain Tensioner For 415 Chain 49cc 60cc 66cc 80cc Gas Motorized Bicycle Bike

this will work well with single speed bikes, but i have an 18 speed. the idea is to use your existing derailleur to shift through your back set of cogs. well the sprockets on the bottom bracket are 1/8 inch. fine for the small chain they supply, which is to short. when you try to run a 5-6-7 speed chain, which is 3/32 over the sprocket, it won't set. luckily for me i have a shimano 6 speed rear cog and shifter. they allow just enough room to use a single speed chain. was hoping to go for a ride today, have to wait till thusday for the chain to arrive now. i ordered some chain to swap out so i don't have to grind down the sprocket. be warned you will need to use single speed chain or modify ( or replace ) the drive sprocket to your rear cog. if you are mounting to a internal geared hub tht uses a single speed chain, you should be fine, except for maybe needing a longer chain from the jack shaft to the front cog. there are no instructions, but it's easy to figure out. the bearings need to be tapped /pressed on the shaft, as does the larger gear. the kit came with all of the hardware needed. all an all not to bad a buy, just wish i knew ahead of time the sprockets were 1/2 x1/8. costing me an extra 50 bucks to make this work. i got this kit because i have modded my engine enough to keep longevity, but be as torque driven as it can get. with the right rear sprocket i could get past 50mph. it's just slow to get there with out pedaling ya patooter off. with the kit i should still be able to get to 45 mph, just at a lower rpm. i want hill climbing, with speed when needed, and better gas mileage. this kit should give me everything i want. a homemade legal motorcycle i can ride anywhere. as long as you dont speed where i live, or have a huge motor, they never check the hp rating. so you can ride the trails like a beast, but still putt around town at 30mph and the cops are cool. the law here allows for transmissions of more than one speed. AHHHHHHH, i want my bike on the road again. dont forget to buy chain if you put this on a mountain bike!!update: well my engine keeps blowing the chains on the bike side. to much power. lol. hit 46 mph, then ran out of road. was gonna do one last run and boom, blew a chain. fixed it, did another run, 45mph, boom blew the chain. blown the chain 5 times on the drive to the back wheel and 4 times on the outside from the jackshaft. switched to 415 chain from the shaft to the free wheel. my free wheel sprocket has a wobble, hence 4 stars. i'll have to buy another free wheel some time in the near future.update 09/25/2019: well it's still holding up. i keep it well lubed, and the wobble hasn't gotten any worse. seems like 46mph is my new top speed. i lost 4 mph, but gained a ton of gas mileage and can take off from a stand still. all in all a win. i haven't got a new freewheel yet, this one is doing fine with wobble and all. i'd buy this kit again and may do so on my next build. makes it a little harder to start, but the advantages more then make up for it. more like kick starting a motorcycle now instead of bump starting. takes a bit to get used to starting it this way.update 1-11-2020: an i'm barbra walters and this is 20 20. not not really. any way. i wanted to know what would kill this freewheel. i found out. to start with i went easy on it for quite a long while. i ride thousands of miles a year on my bike. i put about 1500 miles on this free wheel before going bonkers. it hung in there, no problems at all. o kept it wll lube and cleaned it after each ride if it was wet, dusty or way muddy. i lubed it at a min after every two rides. a ride could be 50 miles to 100 miles in a one way shot, to repeat it on the way home, with maybe even more miles on the way back. lots of cruising. smooth kick starts for that whole time. well for the learning curve lets forget. then i went balls out, kicking mud, eating trails for breakfast. i lubed after and before each ride. it held up for quite a beating. another 500 miles of mostly trails in the woods. long hard pulls, quick raps, you name it. mud holes, trees, fun times. not to bad for what i put it through. if you treat it good, i'm sure you'll get many thousands of miles out of this. i did.

The kit doesn’t come with instructions, that much is common knowledge. But the shaft gears, the shaft, and the pin holing them all together needs minor machining to get them to go together and come apart without percussive methods. In addition to this, this kit is designed to work on pretty much every bike that can house the original engine kit EXCEPT for cruiser bikes; The crank assembly is incompatible with the crank supplied. Furthermore, you better look for a community bike shop that has scrap bike parts like derailleurs and shifters and stuff like that, cause you’ll need it. It works, but it’s a real project.