Grubee Rack Mount on a Fuji 29'er

Discussion in 'Rack Mounted Engines' started by ocscully, Aug 9, 2010.

  1. ocscully

    ocscully Member

    A friend of mine bought a Grubee Rack Mount Kit last week from a member of this forum and we have begun the process of getting it set up on his 2006 Fuji 29'er city bike. This kit came with the type III Gearbox. The rack on this kit had had alignment issues in the past so we started out making sure the rack was flat, and that the legs were set up properly. The mounting plate was also no longer flat so I built a new one out of 1/4 in. aluminum plate. The rack is designed to mount over the rear axle but since this bike uses QR Hubs I built a pair aluminum tabs that bolt to the fender and rack points of the rear dropouts. I've also made an upper attachment bracket that mounts to the mono stay on the chain stays. We did a test fitting of the new parts this afternoon, and with a few mods to the parts tomorrow its looking like everything is going to work well.

    ocscully
     

    Attached Files:

    Last edited: Aug 9, 2010

  2. ocscully

    ocscully Member

    More Photos

    Round #2 of Photos.

    ocscully
     

    Attached Files:

    Last edited: Aug 9, 2010
  3. ocscully

    ocscully Member

    More Photos

    Round #3 of Photos.

    ocscully
     

    Attached Files:

  4. MotoMagz

    MotoMagz Member

    Looks like you solved the problem.Nice work!
     
  5. occchopperfl

    occchopperfl Member

    ocsscully,

    u r a good friend.
    great work!

    i have the same kit, (im mechanically challenged btw) bought new mid june and still not done. My goal is to get it running by end of August.
    (I have a huffy cranbrook and the rear wheel/hub and chain/sprocket are my issues)

    Please keep posting. Thanks :)
     
  6. ocscully

    ocscully Member

    Thought we were going to have the bike up and running late this afternoon, but hit a couple of snags that are going to put the operational phase off until tomorrow. The new mount plate needs a bit more work to provide enough clearance between the 11t output sprocket from the gearbox and the bottom of the mount. This area is really tight even with the stock mount plate and the extra thickness of the 1/4 in aluminum plate made it so the chain couldn't make it thru the gap. In hopes of getting it operational today we went ahead and used the stock mounting plate. One of the unique things about this rack mount design is that you are able to use the leg turn buckles to raise and lower the mount portion of the rack to control the left side motor chain tension. The second major snag of the afternoon was with the throttle cable, it wasn't long enough and the cable end at the carb wouldn't allow the throttle to return to idle position. We went to a couple of the local bike shops to pick up some brake cable housing and a tandem length brake cable to make up a new proper length throttle cable tomorrow morning.

    ocscully
     

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    Last edited: Aug 11, 2010
  7. ocscully

    ocscully Member

    Bike is Done

    Spent a couple of hrs. this morning building a custom long length (73 in.) throttle cable. Used a tandem length brake cable for the inner wire, and an oversized Nicropress fitting for the cable end. The fitting was then filed down to fit the cable stop on the carb. Once the cable was complete is was just a matter of installing it and the fuel tank and then extending the kill switch wiring. Let the test rides begin.

    ocscully
     

    Attached Files:

  8. ocscully

    ocscully Member

    Last 4 Photos

    Last 4 Photos

    ocscully
     

    Attached Files:

  9. occchopperfl

    occchopperfl Member

    Very nice! :)
    Hows she ride?
     
  10. happycheapskate

    happycheapskate Active Member

  11. wbuttry

    wbuttry Member

    i wonder if that can be done with a normal frame mounted engine i dont see any reason it couldnt does anybody else?
     
  12. happycheapskate

    happycheapskate Active Member

    Most of the "29'er" mtb frames have sharp angles and deeply sloping top tubes, to accomodate a long fork and tall tires. I think the seat tubes are usually rather large too for frame stiffness. If a grubee kit fits in there, the plug will likely contact the top tube.

    Some large frames with more conventional frame diamonds might work, but I wouldn't like to put a frame mount motor on an aluminum bike. The tubes dent easily and they get vibration cracks.
     
  13. shiloh0

    shiloh0 New Member

    how does the gas flow up to the carburetor--it looks like the tank is mounted below the carb?
     
  14. happycheapskate

    happycheapskate Active Member

    What is a nicropress fitting?
     
  15. occchopperfl

    occchopperfl Member

    I think it has to do with the feul system:

    "Rear mount engine has closed loop fuel system. V-Frame mount does not"
    (Quote from Grubee 4GT 4 Stroke Info.)

    Add:
    And maybe also because the gas tank is not vented?
     
    Last edited: May 31, 2011
  16. shiloh0

    shiloh0 New Member

    that makes sense, occchopperfl, i see the 2 lines going from the tank but was confused cause i have one of those engines in the frame-mount version and it doesn't have any diaphram pump and return line.
     
  17. ocscully

    ocscully Member

    The Grubee Rack Mount Kits come with a different Carb than the Frame mount Kits. The Rack Mount kits get a Pumper Carb. They have a diaphragm in them that draws the fuel up to the motor rather than relying on Gravity.

    NicoPress fittings are Industrial Swage Fittings used for cables or wire rope. The are pretty much a heavy duty Crimp on fitting. http://www.nicopress.com/C1.htm It made the process of making a custom length throttle cable easier as I had access to them, rather than silver soldering on a new tip.

    ocscully
     
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