Front Drive Question

Discussion in 'Rack Mounted Engines' started by lowracer, Jan 20, 2010.

  1. lowracer

    lowracer Member

    Has anyone ever mounted an engine on the lower section of an MTB front suspension fork? Will it mess up the forks in any way? I have a Marzocchi Junior T w/ a 20mm thru axle that I may try this on.

  2. Mountainman

    Mountainman Active Member

    should not have enough
    even come close
    to messing up the fork

    ride that thing​
  3. I'm not comfortable with too much weight carried low on the front of a two wheeler. The mass makes steering and handling sketchy. Try mounting a roughly similar weight to the same area of your bike you intend mounting your engine (hurrah for ductape) and see how it handles.
  4. wheelbender6

    wheelbender6 Well-Known Member

    Electric front hub motors are commonplace. Give it a try.
  5. Wheelbender, what you say is true, but the weight is centered between the forks and is also centered at the point of rotation on the axle. Moving the weight to the side and off the center of rotation has a vastly different effect on handling. It involves inertia, center of mass, polar moment of inertia, etc. etc. like I said earlier, try it and see. Experimentation is the heart of knowledge.
    Last edited: Jan 20, 2010
  6. 5-7HEAVEN

    5-7HEAVEN Guest

    I installed 2.2hp Mitsubishi engines on Staton friction drive, front and rear. It was easy to install the drive on a solid fork. Then I took a few months to figure out how to place the front drive onto a ROCKSHOX fork. The setup worked very well for me. It took a while to get used to walking the front-loaded bike. Once it got rolling, you couldn't tell that you had a front motor.
  7. Warner

    Warner Member

    5-7, how do you like those Mitsu engines so far? That's what I'm using on my bike, too. I probably only have about 500 miles on the engine....just wondering how you like them. It seems like a good little engine. If I remember correctly, you did some hop-up work on yours, no? Mine is all stock....with the exception of a 2nd muffler to quiet it down a bit.

    Let me know and thanks,

  8. lowracer

    lowracer Member

    Thank you for the replies on this topic.

    I'm going to be using a Subaru-Robin EH035 with a Staton clutch housing & 1/2" shaft. A 1" v-belt pulley from Mcmaster-Carr & JB Weld to join a 26" (559) rim hoop to the 559 front wheel for belt drive. I'll buy some aluminum bar at Home Depot/Loews to fabricate a triangular motor mount connecting the 20mm thru axle ends to the unused V-brake bolts (bike has Hayes hydraulic discs). I want to fashion some kind of cable operated spring tensioner with one of them brake levers that have a locking button to hold the cable in a pulled position. Unlocking the button will allow easy belt removal for pedal only w/ no drag...Its a triple clamp fork that looks like what comes on a Motorcross dirtbike.

    ---> Has anybody added an aftermarket muffler to a Robin EH035 to direct the spent gasses downward & hopefully make it as quiet as possible without killing the power?
  9. Warner

    Warner Member

    Is there a way to use the staton hub/freewheel and a chain for the front? That would seem like a simpler and better system to me....if it could be make to work. Maybe I'm not thinking about something design wise, though....

  10. lowracer

    lowracer Member

    Gearing would be an issue using a Staton chain hub/freewheel. You'd need to have a Staton gearbox to reduce the gearing from the 7000 rpm motor to the small chainwheel & it is costly. My goal for this project is do it as cheaply as possible with as little permanent alteration to the bike as possible. Only permanent change here is the rim JB welded to the wheel.
  11. Warner

    Warner Member

    When you say "rim JB welded to the wheel", are you talking about something like what Golden Eagle uses, with a drive wheel attached to the spokes somehow? You lost me on that part....

  12. Warner

    Warner Member

    PS - Have you thought about simply using friction drive on the front wheel? That certainly sounds like the SIMPLEST and probably cheapest method....

  13. lowracer

    lowracer Member

    I've thought about friction drive but didnt want the tire/roller wear. It also would limit tire selection to slicks. This belt drive could also be used for some offroading & knobby tires. The rim to rim weld is simply taking an exact rim hoop size as your front wheel & either welding on or JB Weld (epoxy) gluing it on. It would act as a 21" pulley wheel to get the correct gearing using a front pulley of about 1"-1.5" & a cheap automotive type A, V-belt. GEBE uses a smaller engine pulley & a smaller spoke attached drive pulley to achieve the correct ratio (~18.75:1) for these high revving engines. My setup is less expensive (Do-it-youself) & without the spoke breakage issues you hear so much about. I measured the clearance from the wheel to the fork & there is plenty of room (3 cm's)for another rim hoop to be permanently attached to the front wheel.
  14. Warner

    Warner Member

    Of course it's dependant on what the rims are made of, but I would definitely go with the real weld in that setup (NOT the JB weld method). It sounds like the forks will be huge though (wide), to allow that much room for another rim to run like that. You will have to use a special axle with some type of spacers on one side, huh? It also seems like the drive rim will be awfully close to the pavement/dirt, etc....and would be likely to get damaged, no? Belt alignment would also become critical as you wouldn't want it rubbing against the front tire, and you wouldn't want to put a front tire on that is much wider than the rim....Just thinking out loud.....

  15. lowracer

    lowracer Member

    I'm not a welder & this JB Weld stuff is amazing. Welding could also damage the integrity of the thin aluminum rimwall which I want to avoid. The rim pulley is wide enough to allow a thin V-belt some lateral play & engine mounting position will keep the V-belt far enough away from the tire. The fork has a huge 20mm thru axle that bolts on from underneath & has a quick release skewer for additional hold. No spacers would be required. Serious MTB'ing (rock gardens) could pose a problem for the pulley but I dont plan on taking the offroading that extreme.
    I built a MB years ago when I was a kid & used a very similar drive method but with a smaller rim/wheel size & a 2HP Briggs & Stratton engine. Back then, I got lucky with pulley sizing & had a correctly geared MB on the first try by accident.

    This 2WD setup could have interesting mechanics w/ increased traction as the front wheel is being powered & can turn, while you can pedal the rear wheel totally independent of the front...I've ridden/raced front drive lowracer recumbent bicycles (Barcroft Oregon, Zox 20, Raptobike) & they do real well handling race courses w/ lots of turns.
  16. Warner

    Warner Member

    If you've used a similar system in the past, it sounds like you know how to make it work. I'd love to see photos of the completed project...and some videos of it in action if you can do that. Good luck and have fun!

  17. lowracer

    lowracer Member

    Will do Warner...
    I just bought the engine & clutch housing from Staton off eBay a few seconds ago.
    Now to the drawing
  18. Warner

    Warner Member

    Have fun! Projects like that are always both fun AND frustrating. But when you get everything working fairly well, you always have that great sense of accomplishment....

    Good luck!

  19. 5-7HEAVEN

    5-7HEAVEN Guest

    I really like the Mits engines. Troublefree, unlike the GP460 engines I also have. I'm in process of installing Scooterguy chain drive on my Daiamondback bike. To simplify matters, I'm reusing my Mits engine, even though it won't push the bike as fast as the 460.

    My ADA S1 pipes I used on the Mits engines won't clear the frame, so I'll use the stock muffler.
  20. Warner

    Warner Member

    Good to hear! How much power difference does the pipe make on the mitsu? Is it just the pipe or other mods, too?

    Thanks 5-7,