r100r(s or t or whatever...) to dual sport conversion

Discussion in 'Airheads' started by W7AMF, Nov 10, 2012.

  1. Airhead Wrangler

    Airhead Wrangler Long timer

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    Yes, I'd want a spoke rear. They handle abuse much better. 17" or 18" would both work. Depends on what kind of tires you want. For serious offroad work there's a much better selection of 18" tires. Problem is that none of the 4 lug monolever bikes had spoked wheels and therefore there is no such thing as a 4 lug monolever spoked hub, so you'd have to make one by milling down a R100GS hub to fit. You definitely want a 21" front rim, probably 1.85" wide. Forget about a disc rear on a monolever, unless you want to do a LOT of work.
    #21
  2. W7AMF

    W7AMF Yeah Raft'n!

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    great info. so, then, did they make a spoke rear for dual shock bikes? also, switching to an 18 rear, and a 21 front, do i need to worry about rake and trail being changed to much? I dont fully understand rake and trail.
    #22
  3. Airhead Wrangler

    Airhead Wrangler Long timer

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    Yes, all /6 and some later dual shock wheels are spoked. Yes, you're frame geometry will be changing, but wheel size will probably be affecting this quite a bit less than suspension changes. I'm assuming you'll be using longer travel forks at a minimum and maybe a lengthened swingarm, so those will have a much bigger effect on your geometry than your wheel sizes.

    Here's some reading for you:
    http://www.tonyfoale.com/Articles/RakeEx/RakeEx.htm
    #23
  4. W7AMF

    W7AMF Yeah Raft'n!

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    got it! ill be doing some reading!ill probaby run a GS for if i can dig one up. we have a few of the lower halfs (yellow), but i havent found any springs or upper tubes, but i havent looked that hard. were slim on GS stuff. if not, ill go with a suz dr or DRZ front end. not sure on the rear, that will depend on which rear set up I go with. will a dual shock or mono shock swing arm be easier to lengther? does any bike use an already longer swingarm? what about a g/s swing arm? basically is there a longer swing arm i can bolt in? or do they all require making?
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  5. Airhead Wrangler

    Airhead Wrangler Long timer

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    Nope, there's no off-the-shelf solution there. Gonna need to cut and weld for a longer swingarm.

    Just curious, where do you work that has 20 monolever final drives on the shelf? Got a 3 lug 32:10 you want to sell?
    #25
  6. W7AMF

    W7AMF Yeah Raft'n!

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    RePsycle BMW Parts. Ill check. shoot me a PM so we dont get too off topic.

    BTW, I found a 4 lug, spoke rear wheel. its a factory 17. its an edge spoke, so itd be hard to have it relaced for 18". I took a pic. ill upload it when I can.
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  7. Airhead Wrangler

    Airhead Wrangler Long timer

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    That'd be off a R100GS or R - for a paralever final drive.
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  8. W7AMF

    W7AMF Yeah Raft'n!

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    I think your right. Our BMW master mechanic pulled the wheel and final drive to put on his r80st. He says it should all bolt right up. It looks like a mono lever drive on his bench, ill get a pic Thursday of the drive and upload them both.
    #28
  9. Airhead Wrangler

    Airhead Wrangler Long timer

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    Don't think so. You need to machine down the center of the hub to fit on a monolever final drive. Doable, but not a quick and easy bolt-up.

    Go look at part 4 here:
    http://www.stephenbottcher.net/BMW/paraconv.htm
    #29
  10. bikecat

    bikecat Long timer

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    For me the biggest advantage of the Paralever is the cross-spoked wheels which run tubeless tires.

    Reason enough to want a Paralever over a Monolever.

    Anyone has a link to a R1100/R1150 Paralever swap onto a Paralever R100X?
    #30
  11. W7AMF

    W7AMF Yeah Raft'n!

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    How about lacing a 4 lug hub to an 18 inch front rim? Seems easy enough?
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  12. Airhead Wrangler

    Airhead Wrangler Long timer

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    I suppose you could try if they use the same number of spokes, but you'll still have the issue of having to machine the hub to fit the monolever final drive.
    #32
  13. W7AMF

    W7AMF Yeah Raft'n!

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    gotchya. i see that now (internet was down all day yesterday. well, seems doable. im still torn between dual shock and monoshock monolever. im really leaning towards monoshock. i havent decided if i like all of the electronics under the tank or not yet though. anyone have an opinion on the matter? going to start scoping out frames/bikes over the next week or two to make my decision!
    #33
  14. W7AMF

    W7AMF Yeah Raft'n!

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    Found a GS subframe today and have officially started my pile of parts!
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  15. Beater

    Beater The Bavarian Butcher

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    You really need to decide on the dual vs. mono-shock. The HPN guys attach the shocks to the frame ... so the GS subframe is necessary for both.

    I will stress again, If I had it to do over, I would go for the dual shock ... reason being is that in the long run, parts are more plentiful, and it will be cheaper to acquire them.

    But I agree ... the mono-shock looks cooler :evil
    #35
  16. W7AMF

    W7AMF Yeah Raft'n!

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    my boss seems to think he has a GS frame somewhere, if thats the case, I will go mono shock because finding parts at a fair price wont be to big a problem for me. if not, then i will go with a dual shock. not only does mono look cooler but i think it rides better too, and i like the ease of rear wheel removal which is nice if you have a puncture.
    #36
  17. W7AMF

    W7AMF Yeah Raft'n!

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    My next question is... Why lengthen the swing arm? The stock monolever arm was the same length as the g/s arm right? Once the tube in lengthened, how do you lengthen the driveshaft? Or does another bike have a longer arm and shaft?
    #37
  18. Beater

    Beater The Bavarian Butcher

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    All Dual shock ad mono bikes have the same swingarm length. All of the shafts are interchangable. The paralever is about 4" (100mm) longer.

    Grab a tape measure and go to a bike night. Measure the wheelbase of any modern 'dual sport' bike in the lot. You'll see that the BMW is anywhere from 4" to 8" shorter. Extending the swing arm does more for the smoothness of ride than increasing travel. It will also move the venter of gravity towards the front end, and you'll find the bike is a bit more balanced.

    Just one man's opinion of course, but you can (and should) ride it with the standard rear end for 5K miles. just to see what its like.
    #38
  19. W7AMF

    W7AMF Yeah Raft'n!

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    right on. I went and measured some swing arms from the r80st and the later mono shock monolever r100rt and they are all the same. shock mounting point is different though! im assuming the three lug (monolever) rear end will bolt onto any monolever then? I get how to extend the swing arm, basically just cut it on a band saw and weld in more tube. how do you safely extend the driveshaft and at what point do I need to start worry about binding the ujoint?
    #39
  20. Clay Spinner

    Clay Spinner Been here awhile

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    Sounds like a great project... but so that you don't go down the wrong road... I'd start using the search function and read everything you can .... there is a lot to digest and decisions to make. As always... there are pros and cons to everything. I find that deciding what I want is the hard part... once you have that cracked you can narrow down your literature search. Gd' luck and I look forward to watching your build progress. HERE is a start...
    #40