I think I'm the fastest 4 stroke bike in florida!!!

cool i have a ktm 400 4 stroke in my bike frame but in the uk lol and they are illegal here it will definetely do more than 87 the hardest bit of build was getting a hub for double front discs keep trying us brits have always been better engineers lol only joking that a great build mate very professioonal and yes i do have a ktm 400 in mine and yes it is very very scary
 
Hmmm, motor swaps! Love'em!
This is a 50hp KTM 250 2 stroke in a 300 lb Yamaha Blaster 4 wheeler.
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With sprocketing I've done over 85mph on it. Makes it a bit tall in 1st so it is geared for 70mph now.
Will wheelie in all gears at all speeds. I have a 300 cylinder, but, like why? This is too much.

This 125 KTM will do 87 mph (with different rear wheel and sprocket, 70mph as shown).
With a good modern engine, especially a 2 stroke, you can get a lot of speed with little displacement.
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These are heavy machines, 200 lbs, built to take it.
Do you really want to do these speeds on a bicycle frame, weak forks, thin spokes, and sketchy brakes?

Steve
 
My first bike was a 2 stroke that topped out around 35. My second went 43 with stock gearing. I dropped it to about 36 swapping the rear sprocket and it was alright on hills. My third went 29, swapped it all over to a new bike and the motor died. Replaced it and the new one is governed so it did 25. Swapped rear sprocket and it does 30. Am happy where its at, don't feel like impending doom around every corner and hidden driveway. 40 would be awesome for doing long stretches being able to keep up with traffic and take a lane. Anything above that doesn't feel and is not safe with a regular bike setup. The cost and construction quality of a bicycle that can do above that you might as well get a purpose built scooter or motorcycle, as cost and construction quality for those speeds would be comparable if not better. If its your goal to be known for bicycle speed records etc by all means go for it, but remember, danger looms. As I've seen numerous times: 25=crutches, 35=wheelchair. I dread thinking what happens at 45+. Good luck and stay safe.
 
if you havent or are having difficulty im happy to share how i got round the problems of way too much power for a bike conversion get a bike that has a rear disc brake get a machine shop to modify your rear sprocket to bolt to the disc brake pickups so not driving off the spoke you will snap them i am research engineer so i get to use all the machines in my lunch hour for private use fabricate new disc caliper hangars and widen them so you are actually using the rear sprocket inside the chain run as a brake disc cross drill the sprocket( can explain if you dont know what this means ) make sure your brakes are hydraulic disc bike brakes not cable you need to be able to stop hardest bit and most important front end brakes a mountain bike disc even hydraulic will not suffice i modded an aprillia rs125 disc 315 mm to fit bike hub and welded calipers to forks i would do away with ideas of the 6 speed box and try and get or modify a cvt you will have plenty on your hands without worrying about clutch and gears next this bike of yours will have a power to weight ratio way way above any ferrari or bugatti once its done gently gently does it to start wear a full motorcycle helmet and leathers treat it with respect it will try and kill you
 
I agree with everything there but your hopes of achieving a better power to weight ratio than a ferrari or bugatti. I know that cars are measured with no rider, but the driver's weight is negligible (3000 lb car with 300hp is 10 lbs per hp vs (3000+150)÷300=10.5 lbs per hp) but because we typically weigh more than our motorized bike I don't find it unreasonable to include the driver's weight in the equation (70÷7=10 lbs per hp, but (70+150)÷7=31.43 lbs per hp). To achieve supercar status you need 10 lbs per hp minimum. With the driver on a motorized bicycle you need 22 hp with a 70 lb bike and 150 lb driver. Everything else you spoke was awesome advice, but never claim power to weight ratios above a ferrari or bugatti when with the driver you are nowhere close...a ferrari enzo boasts 4.56 lbs per hp. To match that with a 150lb driver and 70 lb bike you need roughly 48.25 hp. Hate to pop bubbles but I do it to myself all the time :rolleyes:.
 
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Florida can be tough on us. Just hope you're in a cool place where you aren't harassed. Still don't draw attention to yourself. Have fun riding
 
70lbs wh
I agree with everything there but your hopes of achieving a better power to weight ratio than a ferrari or bugatti. I know that cars are measured with no rider, but the driver's weight is negligible (3000 lb car with 300hp is 10 lbs per hp vs (3000+150)÷300=10.5 lbs per hp) but because we typically weigh more than our motorized bike I don't find it unreasonable to include the driver's weight in the equation (70÷7=10 lbs per hp, but (70+150)÷7=31.43 lbs per hp). To achieve supercar status you need 10 lbs per hp minimum. With the driver on a motorized bicycle you need 22 hp with a 70 lb bike and 150 lb driver. Everything else you spoke was awesome advice, but never claim power to weight ratios above a ferrari or bugatti when with the driver you are nowhere close...a ferrari enzo boasts 4.56 lbs per hp. To match that with a 150lb driver and 70 lb bike you need roughly 48.25 hp. Hate to pop bubbles but I do it to myself all the time :rolleyes:.
at is your bike frame made of lead lol
 
70lbs wh

at is your bike frame made of lead lol
Lol. Just a 49cc hs 142f kit weighs 30 lbs dry, almost 35 with fuel and oil added. I don't know about you but I'm not using a 23 lb racing bike with a carbon kevlar frame and nitrogen in the tires. Even that racing bike would weigh 58 lbs with a 49cc 4 stroke kit... My bike is a steel framed huffy cranbrook. I fully expect my bike to weigh over 70 lbs. These larger motors (90-212cc) weigh even more. Lead might be an upgrade :D.
 
Lol. Just a 49cc hs 142f kit weighs 30 lbs dry, almost 35 with fuel and oil added. I don't know about you but I'm not using a 23 lb racing bike with a carbon kevlar frame and nitrogen in the tires. Even that racing bike would weigh 58 lbs with a 49cc 4 stroke kit... My bike is a steel framed huffy cranbrook. I fully expect my bike to weigh over 70 lbs. These larger motors (90-212cc) weigh even more. Lead might be an upgrade :D.
err actually i am using a6061 aircraft aluminium hybrid frame 700c carbon rims carbon seat post stems etc lol and with the gx 160 clone after i stripped the bits off engine not required it ways about 45 lbs with engine and 1.5 litres of fuel lol not that it makes any difference it was just the bike i had spare at the time
 
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