Zoombicycles 80cc slant head

Discussion in 'Motorized Bicycle General Discussion' started by MotorNut123, Sep 23, 2010.

  1. MotorNut123

    MotorNut123 New Member

    Joined:
    Aug 31, 2010
    Messages:
    220
    Likes Received:
    0
    Hi I'm wondering if anyone has used the the 80cc zoombicycles slant head before. Is it a good buy? And will it fit on any 80cc motor?
     
  2. RedB66

    RedB66 New Member

    Joined:
    Dec 28, 2007
    Messages:
    1,023
    Likes Received:
    0
    I've used about six of them with no problems..... 129 with free shipping is a good deal.
     
  3. MotorNut123

    MotorNut123 New Member

    Joined:
    Aug 31, 2010
    Messages:
    220
    Likes Received:
    0
    129? I though it was only like 13 bucks. I'm just gonna get the head.
     
  4. DudeZXT

    DudeZXT New Member

    Joined:
    Jun 20, 2010
    Messages:
    115
    Likes Received:
    0
    I think there are other modifications you have to do if you only swap the head...

    Search for a post that says slant head now available, I think it's all in there.
     
  5. mobike91

    mobike91 Member

    Joined:
    Sep 14, 2010
    Messages:
    111
    Likes Received:
    2
    its a real good motor kit. im running it now.
     
  6. chainmaker

    chainmaker New Member

    Joined:
    Jan 19, 2010
    Messages:
    2,597
    Likes Received:
    1
    Dont know about the head alone but Im also running the kit now excellent!!!

    Cheers
     
  7. bairdco

    bairdco a guy who makes cool bikes

    Joined:
    Aug 18, 2009
    Messages:
    6,403
    Likes Received:
    50
    based on my and other's experiences, the slant head does absolutely nothing for performance. it's a pretty poor design, prone to overheating and warping, and the only real reason to get one is if a straight head doesn't fit in your frame.

    all of my straight head motors run circles around the slant.

    i think it's a waste of money, and definitely not an upgrade.
     
  8. TheE

    TheE New Member

    Joined:
    Jun 26, 2009
    Messages:
    187
    Likes Received:
    0
    I got a slant head from ZB once for my 49cc. It had a bunch of cracks in it and the spark plug threads stripped out causing it to leak. They said it was just a bad batch and sent me another one, same problem. After that I went back to my regular head and called it a day. I guess it depends what "harvest" you buy it from =p
     
  9. doubledice

    doubledice New Member

    Joined:
    Nov 6, 2009
    Messages:
    130
    Likes Received:
    0
    I have a zoombicycle slant head and it hasn't failed me once. Iv ran it straight open for over a mile in triple digit weather before and it was fine.I ride my bike pretty hard, maybe i just got one of the good motors who knows .bf.
     
  10. Salty Gator

    Salty Gator New Member

    Joined:
    Aug 3, 2009
    Messages:
    672
    Likes Received:
    0
    Listen to the "Baird".....he knows everything.....(grin)....Zoom engines are the only I've ever used....not a single issue yet....the intake ports on these engines are larger than other makes....more mixture...more power....I've heard of slant heads overheating and warping but I've never encountered this...to me it's more bang for your buck.....just my 14 cents worth...( adjusted for Obamanomics)




    Salty.shft.
     
    #10 Salty Gator, Sep 26, 2010
    Last edited: Sep 26, 2010
  11. kelly1

    kelly1 New Member

    Joined:
    Aug 22, 2010
    Messages:
    3
    Likes Received:
    0
    I have the slant 80 kit on a mountain bike and I'm impressed so far ,ordered a second one for a winter project .
     
  12. DudeZXT

    DudeZXT New Member

    Joined:
    Jun 20, 2010
    Messages:
    115
    Likes Received:
    0
    I started with a straight and followed with 2 slants. The slants both outrun the straight, big time. 6 months kicking.

    I'll say it again, Zoom is a great company who stands behind their products and will go the extra mile to make things right (short shipment mistakes, warranty issues and such)..
     
  13. MotorNut123

    MotorNut123 New Member

    Joined:
    Aug 31, 2010
    Messages:
    220
    Likes Received:
    0
    Ok. Does anyone know how the angle fire head is? Bikeberry and I think piston bikes carry that
     
  14. bairdco

    bairdco a guy who makes cool bikes

    Joined:
    Aug 18, 2009
    Messages:
    6,403
    Likes Received:
    50
    i'm just sayin'. i've got a Grubee GT5 with the slant head, and i did the same thing to the motor that i do to all my bikes, and it's slower than all my GT4's with the flat head. there's another thread that's like 50 pages long, and if you read it, take notice of who's posting for and against it.

    you'll find most (if not all) the experienced builders say it doesn't do anything for performance.

    it may work just fine, but as a performance upgrade, no one's proved that it does anything at all, so in my opinion, unless you need one for clearance issues, save your 13 bucks and buy a 12 pack instead.
     
  15. BarelyAWake

    BarelyAWake New Member

    Joined:
    Jul 21, 2009
    Messages:
    7,209
    Likes Received:
    5
    The theory with the slant head that's supposed to be for "performance" is the spark plug's orientation, angling the plug allows for more of the spark area to face the fuel/air pulse directly - if properly indexed and the head is on the motor in the correct direction (plug on intake side).

    Thing is, not only are the benefits of plug indexing somewhat controversial in the first place even amongst the pros (if there's not a profound enough difference to prove a result - is there a result?), if you do what baird's suggested - search through those that claim performance increases, you'll note that the head's installation is completely random (tho I've not seen one on sideways yet lol) with no mention of proper plug indexing...

    Which leads me to conclude that the reports of performance increases to be mostly based on the placebo effect and/or an inadvertent increase in compression by repairing an existing head gasket leak/thinner than original gasket (which can ofc be done w/the regular head).

    Which leads us back to "if there's not a profound enough difference to prove a result - is there a result?" ;)
     
  16. MotorNut123

    MotorNut123 New Member

    Joined:
    Aug 31, 2010
    Messages:
    220
    Likes Received:
    0
    12 pack?? What is it?
     
  17. DudeZXT

    DudeZXT New Member

    Joined:
    Jun 20, 2010
    Messages:
    115
    Likes Received:
    0
    I weigh ~200 and my brother-in-law (who weighs 300+) scooted pretty good on one of my builds with a slant head.

    I'm talking factory slants, though, not aftermarket changes... Pbbbt!
     
  18. Goat Herder

    Goat Herder Gutter Rider

    Joined:
    Apr 28, 2008
    Messages:
    6,251
    Likes Received:
    3
    I am purely saying that a guy weighing a 130 pounds is a night and day difference from 210 pounds.

    The 210 + guy is the one with wore out spokes and a broken stud on a motor mount in say 1000 to 3000 miles. For every action there is a reaction. Something has to give.

    A guy weighing next to nothing will have a scooter that moves.

    I 've known of kids that are light enough they drill holes in there rims etc. [None motored] Don't ever do this to a motored guy's. My point being is weight is never accounted for by the light guy. Who always says its a working.


    I got a friend running a slant head with a text book correct pipe on it and after market carb that would run neck to neck with my stock 5.8 Morini. Me 240 pounds heavier bike. Him lighter bike and he at 210 pounds running direct drive.

    Just saying it is never accounted for. There is so much not accounted for!!

    Sure a motor fighting less compression will rev easier. My buddy with his slant was getting 8000 rpm's out of his motor dialed in perfectly a lot done correctly.


    Now we get to bring up the famous roller cage bearing on the piston that grenades.
    Yes a stock motor with the lower compression head will last longer for a variety of reasons. Except I put brass bushings in my motors.[China]

    Now if we are talking about a stock run of the mill motor. know to motors are ever really the same. One guy can have a slant head and do just fine while another may not.

    Slant head out of the equation two regular head motors side by side may not be alike. I have had the motors both ways. I think it is prolly easier to get more revs out of a lower compression head.

    I prefer the slant head my self. I have so far never warped one or found one warped. This is out of 6 motors that I know of.

    I can only speak from my experience the Zoom slant head motors that I have ordered in the past year alone have the best porting I have yet to see on a china jug. Nice large ports. You put that with a good pipe that thing with rev out just fine.


    If a guy happens to have inferior porting on there jugs well.

    Last there is always a inherit difference between motors one motor may very well be timed differently.
     
  19. Goat Herder

    Goat Herder Gutter Rider

    Joined:
    Apr 28, 2008
    Messages:
    6,251
    Likes Received:
    3
    I ran regular pump fuel in my Bike comparison . The guy running neck and neck with me was running race fuel by the way. [higher octane]

    Something else to think about when you run a higher compression head guy's. The guy running the slant head that could give me comp has a brass bushing now. He threw a roller cage.

    All this said the motors from china are kits in them selves. A guy's best bet for longevity is to keep it simple lower compression head.
     
  20. Goat Herder

    Goat Herder Gutter Rider

    Joined:
    Apr 28, 2008
    Messages:
    6,251
    Likes Received:
    3
    The motors I now put together because I am heavier and demand more have balanced cranks now too.
     

Share This Page