From the beginning of the build my goal was a 45mph bike. I was calling it the "Sprint", but after mocking it up and breaking in the engine I started calling it the "Rattletrap" because of the exhaust note. It rattles like a dirt bike... After 6 months of building including 2 months waiting for back ordered parts and 1 month waiting for a replacement 11 gage spoke that I lost the Rattletrap is done.
She's powered by a 66cc china 2 stroke engine kit from Motovelo. The engine came with a cut piston and drilled wrist pin. I installed a wrist pin needle bearing just because it came with the engine kit. I purchased a top end performance kit and a 40t rear sprocket adaptor kit from someone else. The top end kit included a 6:1 billet aluminum high compression head that I decided to paint black to cover up the crappy de-burring job, a ported jug that I had to rework, a plenum intake that I had to repair and rework, and a Mikuni VM18 carburetor. I coupled that with a CNS air filter and a banana expansion chamber from Sick Bikes. I fabricated a pipe to covert the banana pipe to an up sweep exhaust and a custom front engine mount clamp. Since I painted the head black I metal finished and painted the jug, engine and carb black too. I replaced the kit chain with a KNC 415 chain and the kit throttle with a Motion Pro throttle. I topped it all off with a NGK spark plug and cap from a local scooter shop.
The GT2A-S frame rolls on Worksman 26 x 2.125 HD double wall 36h alloy rims with 11g stainless steel spokes, Maxxis Hook Worm tires and Maxxis presta valve tubes. I converted the front wheel to a disc brake with a Shimano Deore disc brake hub and a Origin8 disc brake kit. I had to drill out the spoke holes in the hub to fit the 11g spokes. It was at this point that I somehow lost one of the spokes.
I installed a Rock Shox 29" XC28 Mag TK 100 coil fork and had to shim the brake caliper and rotor to fit the fork and had to grind the inside of the fork leg to clear the rotor mounting screws. I went with Sunlite MTB City aluminum handlebars and some cool looking 0-60 degree stem from Bike World here in Las0 Vegas. I used a Black Ops bottom bracket set, crank, and BMX chain ring, with Schwinn black alloy peddles. To hold it upright I used a M-Wave double leg center stand that I originally thought was crap until I properly installed the lock screws it works good now. For comfort I used a XLC coil spring seat post with a XLC alloy quick release clamp, and a Schwinn coil spring seat. Last but not least I used cheep squishy handgrips from K-MART to absorb some of the good vibrations.
Over the weekend I disassembled the bike and painted it. My original plan was to brush the aluminum frame with Scotch Brite and just clear coat it, but I decided to paint the back portion black because of how dirty it gets from the exhaust. It still gets just as dirty but doesn't show it as much on the black paint. I'll install a 90 degree nipple to deflect the exhaust away from the bike.
The bike starts easily and idles smoothly. She runs good with a strong mid range and top end. I haven't reached my goal of 45mph yet, but after I re-jet the carb and drop down to 38t rear sprocket I'm confident that I will reach my goal.
She's powered by a 66cc china 2 stroke engine kit from Motovelo. The engine came with a cut piston and drilled wrist pin. I installed a wrist pin needle bearing just because it came with the engine kit. I purchased a top end performance kit and a 40t rear sprocket adaptor kit from someone else. The top end kit included a 6:1 billet aluminum high compression head that I decided to paint black to cover up the crappy de-burring job, a ported jug that I had to rework, a plenum intake that I had to repair and rework, and a Mikuni VM18 carburetor. I coupled that with a CNS air filter and a banana expansion chamber from Sick Bikes. I fabricated a pipe to covert the banana pipe to an up sweep exhaust and a custom front engine mount clamp. Since I painted the head black I metal finished and painted the jug, engine and carb black too. I replaced the kit chain with a KNC 415 chain and the kit throttle with a Motion Pro throttle. I topped it all off with a NGK spark plug and cap from a local scooter shop.
The GT2A-S frame rolls on Worksman 26 x 2.125 HD double wall 36h alloy rims with 11g stainless steel spokes, Maxxis Hook Worm tires and Maxxis presta valve tubes. I converted the front wheel to a disc brake with a Shimano Deore disc brake hub and a Origin8 disc brake kit. I had to drill out the spoke holes in the hub to fit the 11g spokes. It was at this point that I somehow lost one of the spokes.
I installed a Rock Shox 29" XC28 Mag TK 100 coil fork and had to shim the brake caliper and rotor to fit the fork and had to grind the inside of the fork leg to clear the rotor mounting screws. I went with Sunlite MTB City aluminum handlebars and some cool looking 0-60 degree stem from Bike World here in Las0 Vegas. I used a Black Ops bottom bracket set, crank, and BMX chain ring, with Schwinn black alloy peddles. To hold it upright I used a M-Wave double leg center stand that I originally thought was crap until I properly installed the lock screws it works good now. For comfort I used a XLC coil spring seat post with a XLC alloy quick release clamp, and a Schwinn coil spring seat. Last but not least I used cheep squishy handgrips from K-MART to absorb some of the good vibrations.
Over the weekend I disassembled the bike and painted it. My original plan was to brush the aluminum frame with Scotch Brite and just clear coat it, but I decided to paint the back portion black because of how dirty it gets from the exhaust. It still gets just as dirty but doesn't show it as much on the black paint. I'll install a 90 degree nipple to deflect the exhaust away from the bike.
The bike starts easily and idles smoothly. She runs good with a strong mid range and top end. I haven't reached my goal of 45mph yet, but after I re-jet the carb and drop down to 38t rear sprocket I'm confident that I will reach my goal.
