Glad I found you!

Discussion in 'Introduce Yourself' started by toojung2die, Feb 10, 2011.

  1. toojung2die

    toojung2die New Member

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    Hi everyone! I'm a new motor bike owner from Lost Wages, NV. The bicycle is an AMF Western Auto Galaxy Flyer vintage approximately 1965-1970. I welded a custom front motor mount to fit the BikeBerry engine to the front frame tube (ignore the butt splices, they've been soldered). I realize "Hardly-Davidson" is hardly unique but it's funny so I stole it. I've made some improvements since the photos were taken but this is basically how it looks today. Are these projects ever really finished? I've found many great ideas on this forum. It's a great ride for checking out neighborhood garage sales. I hope to make the longer ride out to Red Rock Canyon when I'm satisfied with the reliability of everything.

    "Too old to Rock n Roll..."

    TooJung2Die
     

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  2. camlifter

    camlifter Active Member

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    looks good. i like the way your using the chain tensioner on the pedal side. saves a lot of headache doing it that way. welcome to the forum.
     
  3. 2door

    2door Moderator
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    Welcome to the forum. We're glad you've joined us. You have a nice build, congratulations. Just a couple of comments.
    Is that rubber in your front engine mount? If so, I'll suggest you get rid of it and mount the engine solid with nothing resilient between it and the frame. The rubber will not eliminate vibrations but simply transfer it to the mounting fasteners and they will eventually fail.
    The other issue is your fenders, especially the front one. Do some reading here, use the search feature, keyword, 'fenders' and you'll see that they can be a source of trouble and potential injury if not installed with some reinforcement in the bracket area.
    Good luck, ride safe.
    Tom
     
  4. Saddletramp1200

    Saddletramp1200 Custom MB Buiilder

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    Hello toojung, welcome. What our esteemed colleague is trying so admirably to convey is simply this. Loose the rubber mount and make it solid so the motor don't break loose and eat your leg. Also the little tab holding the fender to the fork will snap and the fender falls on the tire spins down and then you have instant snow mobile. End Translation rotfl (c)
     
  5. buzbikebklyn1

    buzbikebklyn1 New Member

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    Greetings and salutations fellow moto biker!
    Nice looking ride, clean, simple and fun.
    Please feel free to contact us if you need help... between all of us, we have like 5000 years of M/B experience...
    If we aint seen it... WE WANT TO!
    I'm really good with mounts and drive-trains, I like your front mount.
    I happen to disagree with our esteemed colleague, in that if done properly as yours is, with good quality mount studs, the nylock nuts and a high durometer rubber insulator, it should give you no trouble. I bet it really cancels out some vibration.
    welcome
    BBB
     
    #5 buzbikebklyn1, Feb 10, 2011
    Last edited: Feb 10, 2011
  6. 2door

    2door Moderator
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    Quote: (I bet it really cancels out some vibration.)

    This idea has been discussed here many times before. Mounting an engine in rubber will not eliminate or cancel out vibration. What it does is, as I said above, transfer the vibration to the fasteners, which will eventually fail. You can not compare the mounting system on our little two stoke engines to a motorcycle or car, both of which use resilient mounts. By virtue of the mount design of the engine they rely on a solid, full contact approach which will cause some vibration in the bike frame.
    Soft mounting the engine does not address the source of the vibration, which is the engine itself. Isolating the vibrations to the engine means that the fasteners (studs and nuts) and even the engine case then must carry the brunt of those vibrations, a task they were never designed to do. They will fail. Over tightening them, using thread locking compounds, nylon lock nuts, lock washers or any other method will not remove the stress put on them by soft mounting the engine. This is not just my opinion by the way, it is a mechanical engineering fact that can not be ignored.

    Soft, or resilient mounts used in cars and motorcycles are a two sided affair whereby there is rubber or a reslient material between the engine case (block) its fasteners and the frame in which is is mounted. Take a close look at any automotive or industrial engine mount and you'll see a metal-rubber-metal sandwich, not just rubber on one side. If one was to experiment with this type of mount they might find a noticable decrease in the vibrations transmitted to the frame but you will still have to deal with the remaining parts of the engine and those that are connected to it in the way of vibration effects.

    I'm not interested in blowing my own horn here; what I want to see is a new comer to the hobby enjoying his bike without the frustrations that will surely come from another unsuccessful attempt to soft mount the engine. Every successful and experienced builder here will agree with me on this. Mount the engine as solid as you can get it and enjoy your bike.
    Tom
     
  7. buzbikebklyn1

    buzbikebklyn1 New Member

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    I respectfully disagree 2door...
    The term "cancel out" was incorrect, my bad, but they do mask secondary vibration.
    I'll be a bit more concise...
    A properly thought out and built "soft" mount like that which was described in some what less than technical terms as a "metal/rubber/metal" sandwich will do the trick in dampening out SOME secondary vibrations. Yes, good grade fasteners are a must, but it will work.
    The very nature of ANY single cylinder engines does NOT lend its self well to 100% balancing or defeating ALL vibrations.
    (I used to ride big displacement thumpers/singles)
    The weak cast aluminum cases of your average china girl engine means it can not be used as a stressed member, so the base mount (front frame mount) must not put any torsional or tension or compression loads on the engine cases them selves, in other words a good mounting system "cradles" the engine.

    When the great Eric Buell was tasked with designing the soft mounting system for The Harley Davidson Sportster and the legendary FRX he came up with a solid rear mount and a series of floating lateral links and a front lower "biscuit"
    (no metal sandwich)mount to keep the secondary vibes to a minimum.
    IT WORKED, it canceled out about 70% of the secondary vibes, which is considerably better than a rigid mount.
    Ever ridden on a pre '84 rigid mount Sporty or FX? and then a soft mount post '84?
    The old bikes were like paint shakers by comparison. It worked so well that the factory incorporated the same type of mounting system in all big twins.
    In closing Semi soft mounts work IF they are designed correctly in the first place.
    RESEARCH RESEARCH RESEARCH!
    Ya gotta do the home work!
    Keeping it shiny side up
    (and the family jewels from clacking)
    BBB
     
    #7 buzbikebklyn1, Feb 10, 2011
    Last edited: Feb 10, 2011
  8. toojung2die

    toojung2die New Member

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    I'm laughing out loud guys. Thanks for the concern and suggestions. All ideas are welcome.

    I did my homework before putting it together. I don't have to worry about the fender brackets breaking off or coming loose. There are no fender brackets on this bicycle. The fenders are bolted to the frame with a fender washer and red Loctite. I read the horror stories about fenders but I gotta have'm.

    There is rubber between both my motor mounts and the frame but it's there for a better fit, not vibration dampening. That's hard neoprene. The engine is solidly mounted and there's no motion between the bicycle frame and engine block. Everything I may want to remove in the future got blue Loctite. Hardware that is mission critical got red Loctite (like engine mounts). Stock screws were replaced with socket head cap screws.

    The weakest link I see is the stock chain tensioner. It's no longer on the pedal chain and moved to the engine drive chain because the drive chain was too close to the chainstay. I have the four bolt ball bearing type but I trust it less than the fenders. Since I can weld I'm going to make one like this:
     

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  9. 2door

    2door Moderator
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    Golly,
    That looks familiar. And here is an engine mount that looks a lot like yours but without the rubber.

    These are both my designs. Neither have ever given me any problems.
    As for the comparisons' with a four stroke motorcycle engine from the other member...
    These are not four strokes but two stroke and single cylinder...
    A 2 stroke single cylinder engine inherently produces a vibration due to its lack of an opposing pulse producing cylinder/piston/mass and even when the rotating components are 'balanced' there will be a harmonic pulse, (vibration) felt and experienced by the assembly it is bolted to. There have been efforts to 'balance' the crankshaft/piston in these engines which have proved to have marginal success.
    Nevertheless, builders have experimented with variouis ways to eliminate or reduce the vibration felt in the frame/handlebars of bikes equipped with the Chinese 2 stroke engines. Yes, there are some quality control issues with our engines but they are not the culprit. The problem is the inate fact of physics that can not be changed.
    If you want to soft mount your engine, by all means...go for it. Just have the courtesy to come back here and let us know when your fasteners/engine casting fails.
    Tom
     

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    #9 2door, Feb 10, 2011
    Last edited: Feb 10, 2011
  10. buzbikebklyn1

    buzbikebklyn1 New Member

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    Thats a sweet mount 2door, is it off set any left or right... low in the frame, simple, effective, looks good... nice work.
    The shop I work at prefers bolt on front mounts due to the ease of manufacture
    Looking back at the shops records, I've built 27 china girl based bikes for customers both left side sprocket and right side jack shaft drives... only one ever came back with a cracked mount, and it had been crashed.
    I've tried many different types of front mounts, single sided ones like yours and double sided ones.

    Thats the beauty of out sport/art/hobby theres LOTS of room for interpretation and other ideas besides our own.
    Doing it my way...
    BBB
     
  11. buzbikebklyn1

    buzbikebklyn1 New Member

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    Dont worry about it toojung2die, we do this sort of thing all the time...as long as its polite ... hey no harm done we here all have our own way to do things, that's the part I enjoy.
    Ride Free-
    BBB
     
  12. 2door

    2door Moderator
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    Buz,
    It isn't offset, just down the middle. I've experimented with bolt on and welded mounts of the same design. The advantage of the bolt on is that it can be moved to another bike...of the same frame measurements, obviously.
    We've high jacked this thread but maybe it will serve a purpose of education, if not just displaying what different minds can do to solve a problem.
    By the way, that bushing is a very stout item. No resliency you can discern. It's hard as a rock :)
    Have a good ride.
    Tom
     

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  13. buzbikebklyn1

    buzbikebklyn1 New Member

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    I dont mind if its moved if you dont... lol
    The bolt on job looks good as well, and its got the advantage of NOT having to repaint, a big plus if your selling these bikes.
    Where do you get those rubber bushings? I'd like to order a few.
    Motor mounts are important, lets take it to the tech threads.
    BBB
     
    #13 buzbikebklyn1, Feb 11, 2011
    Last edited: Feb 11, 2011
  14. 2door

    2door Moderator
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    I think we can let it go. This discussion has been hashed over often in the "mounting' section.

    I still like the OP's bike. It's a nice clean build that should give him a lot of pleasure.
    Good talking to you.
    Tom
     
  15. toojung2die

    toojung2die New Member

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    "Imitation is the sincerest form of flattery."
    Charles Caleb Colton

    Very nice work. My stick welding is not nearly as pretty. I saw the photo while searching the chain tensioner threads. I find it ironic that after having years of fun building a tire smokin' neck snappin' turbo Eclipse I'm finding as much pleasure at the opposite end of the horse power spectrum. A lot easier on the wallet too!

    Too old to rock n roll,
    TooJung2Die
     
  16. 2door

    2door Moderator
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    TooJung,
    As you can see from my avatar, I'm no stranger to the more expensive forms of transportation. Drag racing, street rods, muscle cars...they are cool, but for the price of one Halibrand rim on my sedan, I can have a motorized bike that gives me a lot of pleasure.
    Keep us informed on how your bike performs. It certainly looks good.
    Tom
     
  17. toojung2die

    toojung2die New Member

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    Hi Tom. The bike is performing well. It's a hop on and go ride. I have several hundred miles on the odometer and have taken the Red Rock Canyon ride a couple of times, a forty mile round trip. I have complete confidence in the rubber I used in the mounts because just like the custom mount you made, it's rock solid and there's no movement. The fenders have stayed tight because this bike has no welded tab to fatigue and break.

    This winter my project is restoring a badly neglected 1985 Yamaha QT50 I picked up real cheap. Having a riding mate is more fun and when I'm done they can come along on the factory built. I gotta admit, the Yamaha is a smooth ride but I prefer the bike I put together.
     
  18. 2door

    2door Moderator
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    Toojung,
    Thanks for the update on your build. I'm really glad you're enjoying your bike. That's why we build 'em, Right?
    Have fun and best of luck on that Yamaha resto. If possible share a photo or two of the finished project with us.
    Ride safe.
    Tom
     

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