My electric start full suspension predator 212 build

Discussion in 'Motorized Bicycle Welding, Fabrication and Paintin' started by romerider153, Dec 4, 2015.

  1. romerider153

    romerider153 New Member

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    What broke was the axle inside the rear Hub so I have to get a new three speed hub I'm starting to give up on the internal geared hubs on motorized bikes my basement looks like a graveyard for them.
     
  2. Amarion1

    Amarion1 Member

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    Ahhh yeah I gotcha. I know nothing about them. Although I do rather enjoy a simple sprocket set up =-)
     
  3. KCvale

    KCvale Active Member

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    212cc is not a motorized bicycle, it's like trying to replace a 2.1L Yugo engine with a 550 horse turbo charged 5.5L V-8 and expecting the cars drive train to take it.

    If you want a big engine in a bike get a motorcycle frame, with pedals...
    The $2000 MotoPed bike will take anything you throw at it.

    [​IMG]

    [​IMG]

    Otherwise you are just pissing into the wind of common sense bud, it may fit, but that don't mean the rest of it will hold up, watch any Home Improvement TV episode to see RedNeck "More Power" examples.

    Hey, just my advice, take it or leave it... broken on the side of road is all.

     
  4. romerider153

    romerider153 New Member

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    I have broken internal hubs with the 66cc 2 stoke as well
     
  5. 16v4nrbrgr

    16v4nrbrgr New Member

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    I've broken them with a 1500w electric bike before. I think that maybe using a geared hub as a jackshaft spinning at higher revs with less torque multiplication at the input sprocket will lessen the forces inside the hub and make one survive. I would be interested to see of this works out.
     
  6. LandSpeedRecord

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    Awesome build. One of my favorites of all time on the forum. I love the Predator motors for motorized bicycles, just wish I could build more of them. I read about the same results over and over on the internal hubs. If you use them as a jackshaft they do well since it spreads the load across so many more teeth. But when they are used in the wheel they will only stay together with very weak motors and I imagine extremely tame riding. But what fun is that for those of us that like some real power. Good luck on the hub and keep up the good work. The world would be a better place if we all had 212 bikes!
     
  7. KCvale

    KCvale Active Member

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    If by 'tame motors' you are talking ~3.5hp like a souped up 66c two-stroke that sounds likely, never build a shifter over that without a internal engine tyranny, but all the internal shifter I have made have held up.

    Again if you want more power, look at motorcycle parts.
     
  8. Tony01

    Tony01 Active Member

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    Nice build. I'm planning a similar build myself for my 2nd bike.

    Since you have the billet flywheel you can modify your gearing to run single speed and still get a good top speed. Something like 9:1 just run a single jackshaft and the second chain on the left and keep the right side chain for the pedals.

    You can pick up a moped drum brake hub that will make this easier from treat land for about $50 - it has a large moped sprocket on the left and a freewheel thread on the right.

    Not necessarily. BMX parts are strong as well.. and moped parts. Not motorcycle parts.

    By your definition a 'motorized bicycle' is a bicycle with a weak engine used for pedal assist. On the other hand, for a lot of custom "big HP" builders here an MB is technically a 'bicycle based moped'. I saw your site.. weak engine kits on bikes with weak brakes.. and if you can make money building MaBs on that more power to ya.. For people who ride without a full face helmet your bikes are plenty. The first MB i ever rode was similar and a blast to ride. My first build though? a 55mph 4c 3.5hp bicycle based moped.

    A 212cc powered bike comes from the 'bicycle-based-moped' builders. Standard attributes are: Steel frames, custom frame mods and motor mounts, heavy duty rear wheels, large disc or drum brakes front and rear, usually some kind of suspension, thicker chain, expensive tires. They combine the best traits of mopeds and bicycles and are much cheaper to maintain and run than motorcycles (or mopeds)

    So the advice I give here isn't to just go and get a motoped; it's to upgrade the rear hub and driveline equipment to at least moped quality.
     
  9. Venice Motor Bikes

    Venice Motor Bikes Custom Builder / Dealer/Los Angeles

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    How did I miss this thread?!?!

    This bike is awesome!!! (^)

    I've built a few shifter bikes using the Shimano Alfine 8-speed hub... The bikes had really fast 2-stroke engines, & the hubs never had a single problem & are all still working fine after many years. (The only issue with those hubs is the price... $300). :rolleyes:

    I've built a few Predator bikes (all with single speed)... This set up has always worked out great.
    You can gear the bike kinda tall for over 50 MPH & still have plenty of power to take off without ever needing to use the pedals.


    Also... It looks like the tank petcock is much lower than the carb; Is there any problem with the fuel flowing uphill to the carb??
     
  10. LandSpeedRecord

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    Thank you Beginner01 and VeniceMotorBikes all very well said. This thread highlights an awesome bike and demonstrates how far we can push some of these parts and still have good results. I have been back and forth from the motorcycle to bicycle world my whole life and very distinctly understand the differences. And I do have to point them out to new customers sometimes. A bike like this is obviously built by someone who gets the engineering challenges and understands very well what he or she is doing. Just like in building race/high performance cars and motorcycles we may push a part to hard sometimes and have to 're think that part or a way around loading it so hard. This is called development. My goal in this whole thing started in just learning the small motors to go make a run at the under 100cc non streamliner class at Bonneville. Now it's all I do and to see a bike like this just makes me smile ear to ear and know there are others out there pushing what we do forward and building incredible and inspirational bikes like this one.
     
  11. romerider153

    romerider153 New Member

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    Venice I don't have any issues with the fuel I have a fuel pump installed and it works great. Also I have a built 2 stroke that runs a sturmey hub and it works flawlessly. After further research on the i motion I found a few guys who have snapped the axle just riding on a normal bike. I guess there was a batch of them made that had bad axles SRAM is going to warranty it for me just need my friends at the bike shop to send it in.
     
  12. romerider153

    romerider153 New Member

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    Also beginner01 you took the words right out of my mouth
     
  13. romerider153

    romerider153 New Member

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    [​IMG]
    I decided to go 79cc for my gfs bike and got the tank started for that bike as well
     
    #73 romerider153, Feb 17, 2016
    Last edited: Feb 17, 2016
  14. Amarion1

    Amarion1 Member

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    Hey thanks for he reply!

    That bike is badass! I'm building a 79 pred for a guy I work with =-) it'll be sweet but your stuff is way cooler! I accidentally crimped the seat tube when torquing down the jackshaft but fixed it with a greased up piece of solid round stock. Thank goodness that worked! Now she's super sturdy in that area =-)

    What are you going to go with for the clutch? Keep the updates coming
     
  15. Tony01

    Tony01 Active Member

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    What is the dual crown fork you're using on these builds?
     
  16. romerider153

    romerider153 New Member

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    To be honest with you I can't remember i work on all the cars for the local car museum and when I was dropping off a car to them on day they had two sets of them and asked if I wanted them since they knew I built bikes. I pulled all the stickers off so long ago but I remember they were marzoochi knocks offs I believe it was something like zooks. They are awesome and provide a great ride especially for free.
     
  17. scratchbuilder

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    What a great way to add 'rear suspension'. Great detail work.
     
  18. culvercityclassic

    culvercityclassic Well-Known Member

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    This looks like the fork you used:

    http://www.ebay.com/itm/Zoom-26-tri...668771?hash=item3abdc15b23:g:M0wAAOSwstxVc3qi

    It is what it is and you get what you pay for, That being said I have used one before, like the looks, was able to lower it and it did well on the bike I built. I will post a picture when I find it.
     
  19. Tony01

    Tony01 Active Member

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    Yeah you get what you pay for. Did it have any damping inside?
     
  20. romerider153

    romerider153 New Member

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    It's similar to that one mine is decently longer than that one and has more travel and mine is adjustable dampening they ride really nice. Obviously it's not the same as a 1k fork but infinitely better then any springer.
     

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