GT2A 48cc vs. GT5A 66cc

Discussion in '2-Stroke Engines' started by Schuyler, Sep 3, 2013.

  1. Schuyler

    Schuyler New Member

    So, looking at building a 2-stroke bike for getting around campus. Not sure if it matters much in the engine choice, but there will be a lot of hills... After reading that the Grubbee kits were some of the better quality kits to be had, I've been looking at two kits lately: The Grubbee Skyhawk GT2A 48cc and GT5A 66cc kits. Can anyone give me any tips/recommendations/suggestions towards one or the other, or another kit entirely? The price on the two kits is the same.

    Thanks guys!


  2. Purple Haze

    Purple Haze Active Member

    The 66cc kit is the most popular, but I like the 49cc better, as it is much smoother. Vibration is a big problem on a bike, so be prepared to regularly attend to things loosening and falling off. There is a ton of info on this forum on how to deal with it. The larger engine will have more torque all things considered, but the smaller one will get better fuel mileage.
  3. Schuyler

    Schuyler New Member

    How significant of a fuel consumption increase would I be looking at going to the more powerful 66cc kit? The added power would be nice with all the hills here...
    And as far as vibrations, I was thinking of maybe putting holes in the bolt heads and using safety wire to help fight that a little.
  4. Purple Haze

    Purple Haze Active Member

    All things considered, fuel mileage will still be excellent, somewhere in the 50-60 miles per tank range. (2 liter tank) The 66cc has more low end pulling power (nice for hills). The main problem is fatigue, especially the hands, on a long ride. Safety wire isn't the hot ticket, but could be done. I would use blue locktite and check things frequently.
  5. HeadSmess

    HeadSmess Well-Known Member

    i always preferred the 48's.

    and now it seems virtually impossible to find a 48 for less than a 66, so i guess i now have to start using POS 66's.

    not too mention the fact that everyones been brainwashed by this 66cc nonsense about bigger being better and cant believe i use a 48 when i finally stop to let em catch up.... my bike is my advertising :)

    they should have more grunt down low, they do vibrate more, they...meh... hate em. but whatever. 66 is now more popular, so parts are easier to get.
    Purple Haze likes this.
  6. Fabian

    Fabian Well-Known Member

    You need a SickBikeParts shift kit - the most useful method of overcoming the problem of climbing steep hills.

    Do a Google search for "Daves Power Assisted Bicycle" and you will get a detailed look at the mechanical operation of this system, and why "you need it".
  7. Purple Haze

    Purple Haze Active Member

    Hey, HeadSmess, glad to see I'm not the only one who likes the 49cc a lot better. I'm all for fuel economy, (hate making a bunch of shieks rich! lol) The smoothness is an added bonus.