Finally "done" with my build :)

Discussion in 'Motorized Mountain Bikes and Road Bikes' started by jeffyh, May 30, 2016.

  1. jeffyh

    jeffyh New Member

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    It's been a long journey building a motorized bike from a Fixie/single speed flip-flop hub frame but for all intents and purposes I'm done. I gotta give thanks to the people on this forum; You people are awesome and helped me a lot! It started as a manged mess First Build: issues, but it got there. I can see why there are recommended bikes to use as a build...

    Things I had to do to make this "work" and look pretty...
    • Sproket welded to a fixie gear and held on with a lock ring (hub spoke number wasn't compatible with pineapple rag joint and hub wasn't shaped to take the clamp type)
    • Throttle cable kit to get rid of excess length
    • All cables/wires run along frame in heat shrink tubing
    • Magneto and CDI connections using bullet quickdisconnects (went through 2 each in the time it took to build)
    • Soldered the spark plug boot connector to the wire core
    • Back brake (NEED MORE BRAKING)
    • Dual brake handle with ~60/40% distribution
    • Better brake pads (NEED MORE BRAKING)
    • Painted random parts flat black
    • Short filter (had longer angled filter before)
    • Intake offset to fit filter (smoother power over stock)
    • Velocity stack for carb
    • Headlight
    • Rear brake light
    • Rear fender (rooster tail is ridic in the rain at speeds)
    • Wider BB for crankarm clearance past engine casing
    • Crank sproket mounted on inside to keep proper chain line
    • Bent muffler to follow downtube angle
    • Bent chain guide so the pulley was parallel to the chain

    To Do's:
    • Still can't tune carb to idle properly or have smooth power throughout throttle range.
    • Better chain guide that sits in line with the chain
    • Less consipicuous fuel tank

    CONSIDERATIONS:
    • Down/seat tube angle is horrible for mounting. You will need to bend an aftermarket front mount to get it to sit right.
    • Above issue causes chainline issues. You NEED a chain guide, because the chain on the lower side of the engine sproket will hit the casing
    • Make sure your hub is compatible!!!
    • Wider tires would be nicer... Things are kindof sketchy at top speed on 23mm.
    • Keep tires properly inflated if running skinnies. Sidewall flex is no joke and can get you into some scary situations in turns.

    Just wanted to share some pics of my build. If you're running into issues trying to build up a single speed/fixie, feel free to shoot a message my way and hopefully I can help.

    All in all, super fun to build and even more to ride!

    IMG_20160530_145920.jpg
    IMG_20160530_150030.jpg
     
    #1 jeffyh, May 30, 2016
    Last edited: Oct 15, 2016
  2. Alpha Centauri

    Alpha Centauri New Member

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    Looks bada$$! Now all you need is an expansion chamber and either a Walbro or an NT speed carb.
     
  3. Chaz

    Chaz Member

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    I remember this build. Quite a complicated endevour. Glad to see you got it going and it looks nice. I think the tank looks fine.
     
  4. jeffyh

    jeffyh New Member

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    Haha, yup. "Running". Thanks for the help, man. Advice from you and 2door were paramount. I'm still trying to figure out how to clean the chain line. Totally get why you said to get rid of the tensioner. I think it's just a futile effort cause of the bike choice.

    Tank looks fine, but I want less conspicuous and less spilly. I barely keep it a 1/4 full and fuel always manages to find a way out on the turns. Was trying to figure out something to mount on the underside of the top tube that would withstand fuel and tapping for the valve and a screw on breather cap.
     
  5. bluck

    bluck Member

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    Awesome bike I always thought that building on a fixie would be pretty simple only cuz it has a V frame, small frame tubes, and cuz its a simple bike. I guess I was mistaken.
     
  6. jeffyh

    jeffyh New Member

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    It probably could be so don't let that discourage you. I just bought any random bike not paying attention to geometry or hub pattern. Those really were the only source of the blockers. The rest is just added value.
     
  7. Kioshk

    Kioshk Active Member

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    Good to see you solved your sprocket issues. I would recommend that you lower the tenstioner-wheel to its lowest-setting and move the assembly back on the chain-stay. This will lower the chances of the assembly being pulled into the spokes, and will provide a little extra "bite" on the sprocket. It'll also give you the ability to take up slack by raising the tensioner-wheel as the sprocket wears.
     
  8. jeffyh

    jeffyh New Member

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    Thanks, it's on the list of to-do's as it's once again a problem cause of the frame, lol. The chain stay is so radically angled from the seat tube to the hub that to get anything close to a proper chain/pulley alignment that's where it has to be currently. There's a piece of bike tube around the chainstay that keeps it from moving. I started bending the chainguide, but I can't figure out an easy way to adjust it in a way that it angles to compensate for the chainstay angle and a S-bend to have it closer to the wheel. I've played with mounting it backwards, spacers, etc. Essentially, it all comes down to being able to properly manipulate that tough piece of metal. Been looking into better chain guide solutions. If you have any recs, I'd be grateful.
     
    #8 jeffyh, May 31, 2016
    Last edited: May 31, 2016
  9. totalnewb

    totalnewb New Member

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    Better get a new fuel line asap, that looks like one that comes with the kit. Mine has fallen off twice, it hardens as it ages. I'm going to get a new one this week.

    Is your clutch handle on your throttle hand? I can't tell but that might not work out so well.

    The bike looks nice!
     
  10. totalnewb

    totalnewb New Member

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    OK, no on the clutch so sorry about that.

    That looks like a dual front/rear brake, cool concept, I'm unfamiliar with these and would like to know more.
     
  11. totalnewb

    totalnewb New Member

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    This might be a stupid question but is this still a fixed hear rear wheel, that would be tough for me to handle IDK about others.
     
  12. Tony01

    Tony01 Member

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    Consider putting a front fender on as well as the rear. Have you ridden in the rain yet? Above 25mph the front tire creates a vertical line of water that gets you wet right down the middle. I rode no fenders and while my back was dry, I had to hang off to one side just to see straight...
     
  13. totalnewb

    totalnewb New Member

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    Just bought a new fuel line at tractor supply for $10. Came with four hose clamps.
     
  14. ezrider

    ezrider New Member

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    Yeah ditto that. Took my first test ride around the block today...slow, nice and easy at first. Gonna attach the speedo tomorrow and check if there's any interference issues. Sharp snappy bike you got there. Love dem pedals.

    -
     
  15. jeffyh

    jeffyh New Member

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    Sorry for the long reply time... works been kind of crazy and my bike rattled the gas tank loose to the point it spun, and dropped the brackets off mid ride. Was so pissed that it's been sitting in the basement until today for repairs.

    Glued a piece of bike tube to the groove on the underside of the tank and replaced the brackets on bottom with rubber coated conduit holders from home depot. That sucker isn't gonna twist on me anymore :)

    Yeah, it's pretty sick. I was getting by just using the front brake, but got into a few close calls pushing 40mph. Extra stopping power is a must. I don't know how to describe it, but the piece that the cable goes into is on a pivot to keep an even pull on both wires. It works real well. Just set it up to your braking power distribution of choice and good to go.
    http://www.sickbikeparts.com/catalog/product_info.php?products_id=41

    Yup, new fuel line on today's repairs cause it's fallen off on me twice too. Once leaving me stranded far from home with an empty tank and the other time covering my leg on the way to work.

    Oh, god, no. That'd be a deathtrap waiting to happen. Can you imagine how fast your peadals would be spinning on that single gear ratio? lol. It's a flip-flop hub. The single-speed coaster hub side is connected to the pedal drive. The fixie is attached to the engine side.

    That's funny, when I first rode in the rain w/o fenders, my front was fine, and my back was soaked. The skinny tires make a smaller rooster tail. I just manage by keeping the wheel straight as much as i can and letting the downtube block it for me :)
     

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