My ChopR65 Frankencycle is done(purists beware)

Discussion in 'Airheads' started by Jim Day, Jan 25, 2013.

  1. Jim Day

    Jim Day full manic mechanic

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    Just thought I'd share some pics my BMW ChopR65 I just completed today.

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    So the story here is that this was my standard R65 BMW that I got nailed on by a hit and run drunk driver a little over a decade ago.

    The jerk managed to damage everything on the bike, then fled. Bent forks, dented tank, crumpled the exhaust, trashed the seat, bent shock, smashed the instruments, killed the combination switches, etc... (Didn't do my back or right leg any favors neither).

    Now back in 2000 used parts where not as available as today but even now the parts to repair it back to stock would of cost as much as the bike was worth. So it sat for over a decade.

    So Just recently I came up with the idea of making a simple chopper/bobber style bike out of it, with possible off road capability (I've always wanted a GS) using as few parts as possible. It was either that or part it out.

    So I started with the idea of using a DRZ400 Suzuki fork, and a dual sport monoshock in the rear. I got a good fork off ebay for $110 and purchase a stock WP BMW R1200GS Monoshock fresh off a new bike $39.

    I then just worked out the geometry to match shock and fork, and welded up my own swingarm, and extended the drive shaft to fit.

    I might as well confess there is something sneaky going on here. The swing arm is very long extended slightly over twelve inches. That makes it look like a cool chopper, but what is not in the pictures is I made an extension for the top shock mount that adds or lowers the shock three inches and can be changed in a minute or two. When in place the frame becomes level, higher like a GS and relatively fully offroad capable, with a slightly elongated wheelbase.

    I like the idea of dual sports but most look tall and kinda clunky on the road. With this bike I can ride on the road to the desert as a chopper/bobber then raise it to GS height to ride offroad. It's unique, it's cool, and I did it because.....well.....I could.

    So basically only the engine and the core frame around it are original, everything behind it I made myself. The majority is built from either scrap steel from my shop, or modified R65 parts. Like I said the only things added are a tractor seat, the DRZ400 forks, and the R1200GS mono-shock, but none of those components are used in a stock manner and most of the R65 parts have been modified in one way or another.

    Rode it today between showers. The bike was ridiculously easy to ride, I felt totally in control instantly. I built it to fit me, and felt right at home with it as soon as I climbed on, so I'm pretty happy with it. One thing that will change is I'm going to a spoked wheel with a respectable dual sport tire on the rear.

    That Snowflake and decade plus old Metzler made some interesting cornering today on the wet pavement. Which lead to the comment: "Dude your drifting through corners" to which I responded: "I'm not drifting I'm sliding" ha ha ha

    No doubt the BMW purists are writhing in pain about now.

    Be not dismayed: Just last week I restored a perfectly respectable dead R75/6 to running condition.
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    As to that bike well what can I say: Wouldn't run, no oil pressure, no clutch engagement, wires the smoked when I initially hooked up the battery....

    Well it's all fixed now. Running, smooth, plenty of power and after trouble shooting everything on it right down to the hardware, the only real issue it had before was an owner who couldn't take care of it, and did n't now how to put things back together right after taking them apart.

    Let's just say it's got a good home now.

    Jim
    #1
  2. hardwaregrrl

    hardwaregrrl ignore list

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    Neat-O!:thumb!!! I like it....the weirdest looking thing on it for me was the stock turn signals. Those seem to be one of the first things to go when we stray from the original. Did they really survive your crash??
    #2
  3. SamH

    SamH 90S on the bench

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    That looks fantastic!

    Dunno about those indicators though :puke1
    #3
  4. RobboJ

    RobboJ Adventurer

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    I dig it! Once it has a spoked wheel it'll look rad. It reminds me of the R80 from NZ that was on pipe burn a while back.
    #4
  5. Thunderbird

    Thunderbird Adventurer

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    Nice work. It looks great!
    #5
  6. ML WYDELL

    ML WYDELL NED

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    Great work. Could be a hill climbing machine too. Is that the stock exhaust cut down?
    #6
  7. Beater

    Beater The Bavarian Butcher

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    Put some knobbies on it and enter the nearest 'hill climbing' contest you can find!

    Fun project!!! :clap
    #7
  8. bpeckm

    bpeckm Grin!

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    Would love to see more of the "geometry" changes with the rear shock... fabulous idea and very nicely executed, it appears. Purists beware, indeed.... but it seems you have the respect for the engineering and build quality of "The Marque"....:evil


    Love it!


    :D
    #8
  9. chollo9

    chollo9 Screwed the Pooch

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    That's the ugliest fucking thing I've ever seen. :thumbup:thumbup Well done.

    Did you restore your leg to original or did you chop it too?
    #9
  10. benthic

    benthic glutton 4 punishment

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    i LIKE it:)
    #10
  11. Jim Day

    Jim Day full manic mechanic

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    Amazingly enough the turn indicators were one of the few things that were not damaged. the rear bar was bent but that was it not a scratch or crack on the lights themselves. Personally I like the stock turn lights, they are kind of clunky but to me nothing is more BMW airhead then those blocky little lights.

    Actually one of my favorite parts of the bike was how I ended up putting the rear ones under the seat.
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    #11
  12. Jim Day

    Jim Day full manic mechanic

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    Yes.... I was thinking about leaving the whole pipe on, but it had a big dent on the left side.

    I don't know if you ever cracked one open but the muffler has two main chambers, and there is a plate right at the bend with three holes in it that separates the front from the back. Three tubes channel the exhaust from those holes to the rear of the pipe at the taper or cones. The exhaust then travels in reverse back towards the bend and exits through a number of holes hole in the central outlet tube to eventually come out the single hole in the end.

    What I did was cut it at the bend leaving the plate in place and then cut it again at six inches from the cones. I then took that back section cut the center tube at a 1/4 inch back 45 degree angle so I could slide that back piece over the front section like a cap. When pushed up against the plate it still had enough room to vent, but the tubes could slide back into the holes, and outer skin would slide past the plate on the outside.

    I then lined up what remained of the three tubes and put them back in their holes and slid the back piece over the front section of pipe like a sleeve, then tigged it with stainless, with a lot of filling.

    The result is the exhaust is shorter but it works the same way with exhaust pushed back to the cones through the three small tubes, then reversed, before they can to get into and exit through the central pipe. Less travel distance, but similar back pressure, slightly louder, with more thump, but it's actually not annoying like most choopers with overly loud aftermarket pipes.

    I've had about ten people come up to me when riding it and say the pipes sound great. It's a really pleasant chopper type sound.

    Before I heard them I was considering getting some after market short pipes for it but I'm keeping these they seem to have enough back pressure and sound awesome.
    #12
  13. Jim Day

    Jim Day full manic mechanic

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    Thanks!!! All these comments are great but I really appreciate what you say.

    I really love BMWs and I find most of the customizations people do to them really annoying. I especially hate it when people make choppers out of them that look like a Harley with a polished BMW engine.

    My take was to take the idea of what a BMW is then make something unique that kept that BMW feeling. So you are absolutely right. I do respect the engineering and build quality of "The Marque", and tried to work with it rather then against it.

    As to the geometry changes I'll take some pics. I've just built it and it handles great on the road but I want to do some testing offroad, and make sure it works or dial it in before I post anything about it's possible GS type potential.

    It's funny but when I build something like this that I've not seen made before I kind of crunch all the numbers in my head, and I try envision exactly how it's going to function, but you never really know until you use it.

    People have extended swingarms on BMWs but usually a few inches, not a foot or more. In this case the bike handled pretty much like a thought it would except that it accelerated much faster then I expected. You know how it is when your instincts kinda take over, the amount of throttle I'm used to giving those bikes had it revving up pretty fast. I didn't even hit it hard, but when first road it I was like "Whooaaaaaahhhhhooooo hold on this is new!!!"
    #13
  14. Padmei

    Padmei enamoured

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    Absolutely too cool for school my friend. Well done.

    Hmmm wrecked R65 you say? I might have one of those poking around here somewhere...

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    #14
  15. Jim Day

    Jim Day full manic mechanic

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    Ouch!!! You get hit from behind? That rear is crumpled, but it looks like bent forks as well. I'd make something out of that. Too bad it's not here, I'm bored because I can't figure out what to do with myself between projects.
    #15
  16. Boxer Metal

    Boxer Metal Mad Scientist

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    That thing is bad ass!
    #16
  17. Tork

    Tork Pinsetter

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    Put a paddle tire on it and go hill climbing :clap
    #17
  18. Dorzok

    Dorzok Long timer

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    Jim,
    Can I be your friend? FABULOUS bike.
    #18
  19. DiabloADV

    DiabloADV Semi-Occasional

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    How did you fabricate the driveshaft?
    #19
  20. Padmei

    Padmei enamoured

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    The previous owner (not with us anymore) hit a bank & flipped the bike up onto a field - it landed a fair way away on it's arse. I have stripped it down, got a new frame, sent the forks & front wheel away for straightening & that's where I'v left it. I keep tossing up between making a trackbike, bobber/streetracker or hardcore off road bike. Luckily i've got the mortagage, family & work to keep me from working on it:D
    #20