Want an engine on Redbull.

Discussion in 'Performance Mods' started by PedOpt, Apr 5, 2011.

  1. PedOpt

    PedOpt New Member

    Hey Everyone, Newbie here. Say, I want to be able to get the most out of my engine. I have the 66/80cc size engine going onto a single speed coaster beach cruiser. What i want to know is, how can get the most out for speed. The drive sprocket is 41 tooth. Do I need a larger or smaller sprocket? How reliable are expansion chambers for an engine of this size? Is it advised to use an expansion chamber? Thanks.

  2. shell shock

    shell shock Member

    hello, and welcome to MBc. first off, please use the search function. all of yoru questions have been answered already. to give you a quick answer; yes, tuned pipes are an instant gain in performance. to gain speed but loose torque you will need to decrease the size of your sprocket. if you really want the most out of your bike, invest in a shift kit.
  3. retromike3

    retromike3 Member

    speed nils,speed spills

    To me the thing that kills the top speed of these little engines/bikes is not the engine(although it does help) or the size of the chainring (it too has a effect) but the main thing that kills the top speed is the shape of the biggest thing in the wind stream and that is you and for a lesser part your wheels.

    I read somewhere(I think it was bike tech magazine) that the main drag above 15 miles an hour is the wind and if there's something you can do that will cut that drag down you will grow considerably faster.What I did for my bike was to take a pair of handlebars and cut them down. The current bars I'm using are slightly smaller width then my shoulders. I also have my handlebars so that they are about as low as halfway down the drops of my road bike. It may look for peculiar but this little guy really seems to get out of its own way.

    I did some coast down tests with my bike without the engine and my friends knew mountain bike. We had the same tires ( 1.5 semi-slick 26) and at the time we weighed about the same. We both started at the top of fairly steep hill with no pedaling just the push off. The way my bike was set up with the closer together handlebars and the lower body position allowed me to slowly pull away from him and by the time I'd gotten to the bottom of the hill I was half a block in front of him and gaining.

    My current bike has a smaller rear cog, it's a 36 and a tuned pipe so I guess it is a little hotter than normal :devilish:but I noticed the major difference in changing the body position.

    The modern mountain bike has a very bad aerodynamic cross-section. If you can change just a small amount it will make a significant difference in your top speed. The fastest human powered vehicles now are going over 80 miles an hour and that is with a lot less horsepower than what we can get out of these little engines.

    Last edited: Apr 5, 2011
  4. PedOpt

    PedOpt New Member


    Thanks for the welcome. Maybe I put in the wrong search criteria, not sure. I was looking at the shift kits. But none of them really explained the set up other than I could use the shift sprocket on the pedal side.
  5. PedOpt

    PedOpt New Member

    Thanks for the info. I'm using my bike as a commuter since I seem to have issue finding a job, so I'm living on plasma donations and the like. So, using this as a way to save on gas. Especially now with the way prices are. But, I live in an area were the roads spd limit is 45-55 mph. So, want a bike than gain close to that. I'm too poor right now to finish building my motorcycle. And I be a full time college student with a campus commute of 20 miles one way. Thankfully I'm on campus once a week at most.
  6. Stan4d

    Stan4d Banned

    You might consider at least 2 more days there a week.
  7. 5-7HEAVEN

    5-7HEAVEN Guest

    Maybe he takes online classes as well.:cool:
  8. 5-7HEAVEN

    5-7HEAVEN Guest

    You should seriously consider applying for financial aid scholarships.:idea:
  9. PedOpt

    PedOpt New Member

    I take a combo of online and campus courses.
  10. Stan4d

    Stan4d Banned

    Mybe you missed the first part.......so I be repeating that he might consider more. :grin5:

    Forgot the :grin5: the first time so maybe no one caught the humor.
  11. ibdennyak

    ibdennyak Guest

    Nah, I got it. Got a pretty good chuckle, considering my online name. :grin5: Now If I could just figure out how to pronounce a silent 4D. :-/
  12. shell shock

    shell shock Member

    i do.. did lol ^_^ but seriously, to OP do a quick search, you will learn more then if we were to spoon feed you. you need to lurk moar