Designed to work with your existing gears and derailer on your bike, this Jackshaft kit will install onto any 2 strokes motorized bicycle engine kit and allow you to shift gears using your bicycle's drivetrain. No longer will you have a separate sprocket just for your engine kit. This kit is perfect for those looking to get the most speed from their engine without sacrificing low-end acceleration that crucial for taking off from dead stops. Recommended for only advanced users as this kit does not include specific instructions and can allow your engine kit to do dangerously high speeds.
Use your existing gears/dérailleur to maximize the performance and top speed of your motorized bike. This kit bolts onto your bike frame and motor and connects directly to the bikes gear system rather than using a separate sprocket.
Warning: Installation is not for the faint of heart. This kit will allow your bike and bike engine kit to do dangerously high speeds! Install at your own risk.
Recommended for advanced users. The kit does not come with instructions.
*Note: These JackShaft kits have been updated to include thinner, non-dished sprockets for better shifting, a chrome-colored sprocket guard for a better look over the old clear plastic one, and does not include a rear wheel bicycle hub.
Haven't had time to get parts on bike!
Sweet! I just got my Jackshaft kit and I only had a small issue with missing set screws for my new sprockets. Other than that, this assembly is Sweet! What an awesome experience. If anyone needs help, go to youtube.com. I had this on my bike and running in a couple hours. Man, is my bike fast! Thanks Guys!
GEARS I HAVE A 29 INCH BIKE, SO I GOT A 48 TOOTH GEAR AND AND A 36 INCH TOOTH FREEWHEEL GEAR FROM SICK BIKES NO NEED TO FILE ANY OF THE TOOTH AND ALSO USE A 10 TOOTH TOP GEAR ON THE MOTOR, AND I USE THE STOCK MULTISPEED CHAIN AND HAVE NO PROBLEM WITH THE CHAIN FALLING OFF,ALSO DONT USE THE CHAIN THAT COMES WITH THE KIT ITS WILL KEEP ON STRECHING.USE A 410H 1/2 X 1/8 KMC AND IT WILL STAY TIGHT.
TRY THIS INSTEAD OF SANDING THE SHAFT I OPEN UP THE INSIDE DIAMETER OF THE TWO BEARING A FEW THOUSAND.THIS WAY THE GEARS WONT FIT LOOSE ON THE SHAFT.I TOOK A ROD AND TAPE SOME FINE SAND PAPER AND WRAP IT AROUND AND USE A HIGH SPEED DRILL TO POLISH THE INSIDE BEARING,HOLD THE INSIDE OF THE BEARING SO IT WONT SPIN WHEN DOING THAT.AND ALSO LIGHT DEBUR THE SHAFT.
not happy at first but fastest coolest motor bike in these parts overall parts are 2nd rate main bracket is junk had tocut one side off and remove 120thou off and weld back together the bearings fit loosely in bracket had to deal whith that then the shaft looked like rebar I had to chuck it up in my lathe and turn it down to fit in bearings now it works there are better ones out there little more money And the Chinese freewheel bearing lasted 17 miles go american there ultra fast now cruising 40 mph no problem