BMW Alpha

Discussion in 'Some Assembly Required' started by Makr, Dec 25, 2015.

  1. Makr

    Makr I make my own rules

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    As a normal course of action, I race a Yamaha RD400 on the Bonneville salt flats. But this thread is not about that. http://www.2strokeworld.com/forum/index.php?topic=18252.0

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    The famous Bonneville salt flats have been mined to the point of depletion. Meaning the salt is so thin we may never race there again. I hope not. There is a pretty good push to have the mining company try to replace the salt that is piled up on their land, but they really have no incentive to, and the cost is more than anyone involved can do anything about. Thank the BLM for this debacle. More info at savethesalt.org

    Every winter I redesign and build a new engine for the landspeed bike, but since we did not run last year, I have a ready-to-go bike for 2016. The engine I have makes enough power to reach my goals. That with the Ryger two stroke coming out that will change that genre for the better, leaves me with an open winter. My ADD would consume me and I would start drinking again if I didn't fill my time and head with a new project.


    I have been watching a Turkish designer that does incredible futuristic concepts. He is an architect and an industrial designer so this is his hobby/fun. You have probably seen some of his designs. He love landspeed racing. I immediately fell in love with his thoughts on motorcycles. His name is Mehmet Doruk Erdem

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    More; http://cgdrk.deviantart.com/gallery/?offset=48
    https://www.behance.net/dodoreis

    I should have started this a few months ago as I am way into this one. I will try to catch the thread up. This is going to be good, I promise. :D
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  2. Makr

    Makr I make my own rules

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    The design I fell in love with is named Alpha. It has clean aggressive lines. Shark nose and bold side trim as a tribute to Paul Bracq. Exquisite!

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  3. Wildebeest90210

    Wildebeest90210 Long timer

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    Lots of questions...Are you going for an exact replica or inspired by? Engine choice? What will you use it for or will it just be to create what we see here as art? I had a quick look through your 2stroke thread, stopping when shiny bits appeared, a world away from my primitive machining. If, as you say, you are a relatively poor fabricator then I'll be looking forward to the crash course building this.
    All looks very interesting, looking forward to more details. :lurk:lurk:lurk
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  4. Makr

    Makr I make my own rules

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    Thanks Wildebeest. My plan was to make it as close as possible. There have been some concessions made(I am way into his one right now). I am going to make it street legal, so DD art? haha
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  5. JimVonBaden

    JimVonBaden "Cool" Aid!

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    Looks very interesting. What drivetrain, S1000RR or Wethead? Hard to tell from the drawings, but I suspect the RR because of the chain.
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  6. Makr

    Makr I make my own rules

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    I had thought about what it needed for power. The boxer would be cool but too wide. I just happen to have a broken K75 in the backyard waiting for some spark of life.

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    A bike I have ridden for twenty years. I crunched it up a couple of summers ago.

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    It is the perfect platform for the Alpha bike. Just the right size.

    I hauled it to the shop, built a stand, and got busy.
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  7. Makr

    Makr I make my own rules

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    I thought about the S1000, and even started looking for one, but they are still kinda pricey. This is a fairly low budget build.
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  8. JimVonBaden

    JimVonBaden "Cool" Aid!

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    You posted same time as me. The K75 is a bit heavy, but solid and with potential! I've had two!

    This should be interesting! :thumb
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  9. ericm

    ericm Long timer

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    I read your entire RD build thread a while back. I strongly suggest everyone troop over there and read the whole thing. Makr's technical skills are fabulous and his writing is good.
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  10. Makr

    Makr I make my own rules

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    Thank you!

    I started to lay out a over-the-top frame, but could never get it structurally sound in my mind.
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    So I went under. Luckily there are some mounting points under the transmission that I could use. I cant remember if they were center stand mounting points, or what was there.

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  11. Donkey Hotey

    Donkey Hotey De Jo Momma

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    IN! :lurk
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  12. Makr

    Makr I make my own rules

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    I researched every hub center steering mechanism I could find and ended up with a mix of my own and of a patented hub http://www.google.com/patents/US8746721. It is a clever piece that uses a standard Ackermann principle coupled with a hydraulic salve cylinder to actuate it. Will it work? No idea. I am scared it will bind up under the braking forces or maybe Jean-Michel Thiers says he doesn't want me to use his idea. Ether way I have a standard kingpin style designed as a replacement.

    I just cut out a Suzuki? rear drum brake hub to use for the front.

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    Made an inner hub and welded it all together.

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  13. Makr

    Makr I make my own rules

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    As far as the hub itself. It is designed in solidworks to make sure it works before I start cutting.

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    Kinda together.

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  14. Wildebeest90210

    Wildebeest90210 Long timer

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    Does it have to be hub centre? I see the bars must pivot immediately inside the bodywork but I see rose joints and rods/gears? Lots of space in that front cowling?
    Rear chain drive essential to design, conversion in the offing? Parallel chain lines too, I can see an interesting mechanical solution to that too.
    #14
  15. Makr

    Makr I make my own rules

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    It doesn't have to be center hub steering, but I like the challenging aspect of it. There may be a serious streamliner project in the future that I need some trial data from. :D

    There really is not much room in the front. I am going to need to stuff radiators and an intercooler up there too.

    No I am staying with the shaft drive. It is traditional BMW and I like the one sided swing arm. That is the only big change I will be making. Of course that includes the seat design as well. Luckily Mehmet (the designer who just got on board with this) is happy with the changes.
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  16. Wildebeest90210

    Wildebeest90210 Long timer

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    Intercooler? I was hoping that would happen :D Hub centre, because you can, I like a lot, and Mehmet sounds interesting too. Great designer no doubt, does he have a daily ride or is he just an artist? Questions questions :y0!
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  17. DRjoe

    DRjoe Long timer

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    Love your work, read through your two stroke thread this morning and was severely late for work.
    Luckily I'm self employed.

    How long did it take you to design and build that hub steer unit?
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  18. Donkey Hotey

    Donkey Hotey De Jo Momma

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    I am curious on some aspects of the geometry you're going after with that hub setup. Are you tilting the steering axis at all?

    And are you familiar with the concept of instantaneous center of a four-bar linkage? Basically: if you draw a line through the centers of each linkage pivot, where the lines intersect is the point where the mechanism is pivoting at that instant in motion. As the linkage moves, that point will also move, creating some kind of sweep. Like this:

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    Looking at the design, I'm wondering which way the lateral chassis forces are going to push the wheel. Because the links aren't steeply angled toward one another, I'm picturing an instantaneous center fairly far ahead of the axle center. That's going to be your effective pivot point and will cause the steering to have a lot of trail.

    I'm also guessing with that much trail, the tire is going to have a tendency to have an exaggerated turn-in when the chassis leans into a corner.

    I'm not a chassis expert and I didn't stay at a Holiday Inn last night but, I did read Tony Foale's book. I'm guessing that you've also read it and all the experiments he did with strange front end designs. I can't remember at the moment but, he did a lot of experiments with exaggerated trail, zero rake and all kinds of other things. Much of that theory is at play in your design.

    Beautiful work, BTW. :thumb
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  19. Makr

    Makr I make my own rules

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    He is an industrial designer and architect by trade, so this is just fun for him. I am not sufre if he rides. I will invite him here.

    Thank you. Most of it was research. Actual machining time was maybe ten hours.

    Thank you. I have Tony Foale's book and thought about his words a lot when going through the front suspension. I understand what you are saying, and am concerned about the same thing. I'm equally concerned it will bind those links up under braking force. I think it is one of those experiments that I have a back-up plan for.
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  20. Tim_Tom

    Tim_Tom Long timer

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    Damn this is cool! I've always wondered if these art design bikes could ever be built, and actually made to work. I too am an architect by trade and my sketchbooks are filled with motorcycles in the margins... Though I've dabbled in creating some 3d models of my designs, I haven't taken them as far as Mehmet has... Maybe I should dust off a few files.

    Also you have some great skills. Seems a shame that the front wheel is all going to be hidden under the front fairing, it's fantastic. I can't wait to see where this one goes.
    #20
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