Pocket Bike Engine Project 3 (V Belt)

This bike was most recently setup as a DIY rear rack friction drive. I didnt care for the friction drive w/ the high powered engine (bad tire wear) & changed it to a more efficient V-Belt drivetrain. I mounting this pocket bike engine on a lightweight, strong, aluminum rear rack using 1/4" aluminum stock & some 1/2" thick rubber skateboard riser pads as motor mounts to absorb vibration. I'll probably need to flip the handlebars upside down to get more weight onto the front wheel for handling purposes. Here are some pics of the mostly completed project. Check out the cable connection I made using a brass spoke nipple & some silver/lead solder. Instead of having to solder a new end to fit into the throttle slide, I simply cut the too short 42" cable I had, cut a new brake cable to fit into the brake lever throttle controller & soldered the two cut ends into the brass spoke nipple. Works great.
-Lowracer-
 

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Last edited:
bideronit13,
No back brakes.
The engine does a fair bit of engine braking before the clutch disengages the drum. Most weight goes to the front wheel under braking anyhow & the v-brakes out front are well set-up & strong.
-Lowracer-
 
Thank you.
I like the engine on the front wheel more for handling, but I like the engine on the rear more for noise & handlebar vibration. Always a tradeoff...
-Lowracer-
 
Coaster brakes are good for cheapy kid bikes but I haven't heard anything good about them for real bike applications?
I heard there is a company coming out with a 'better mousetrap' coaster brake.
-Lowracer-
 
how about adapting the band brakes from say a kids electric scooter to fit on the end of the engine pulley? use the driveline!

think about the safety break on a chainsaw...

its only the rear... doesnt need to be terribly powerful... more effort than its worth? im in the same boat and just dont have any :)

coaster brakes are good on the ol' bmx...let you ride backwards without having to pedal backwards :D

meh. theyve been around since the beginning in various guises... other than a bendix 2 speed theyre all relatively much the same... i always loved cooking them, holding them on slightly so theyd heat up :) got one to go blue and you could light the smoke coming from it :)

oooh! hows about magnetic breaking on the pulley! a dc motor(generator) switched to a big low value resistor... breaking energy dissipates through the resistor. they do it on busses... :unsure:
 
HeadSmess,
I really dont think the rear brake is necessary on my drive type. When I let off the gas, the engine braking gets the speed down before I ever need to apply the front brake. In emergency slowdown maneuvers, the front v-brake is very powerful. I got the seating position low enough now that I wont go flying over the handlebars when I grab a handful of brake.
-Lowracer-
 
Hello, I am very new to message boards. Thanks for posting this amazing idea.

I just bought a folding bike with 20 inch wheels. Is there anything preventing me from scaling down the sizes of everything a bit?

Also, if you put a how-to video on You tube, it would be wild success!

Thanks again!
 
I've been having expansion chamber withdrawal syndrome (ECWS) since putting on the DAX canister muffler. The little can kills the power output of the 2 stroke engne in a big way & though I thought a little de-tuning would be a good thing for a no-suspension bike, I was wrong.
I had to do quite a bit of re-engineering to get the chamber onto this rig. The engine mounts had to be moved a few inches out & required a full day of re-work.
Got it done today & I like the power...
I also flipped the handlebars, pushed the seat forward, & dropped the seat way down for center of gravity & handling.
Also added the skateboard wheel belt guide/tensioner.
-Lowracer-
What are you using for the large pulley on the rear wheel?
 
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