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

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

  1. W7AMF

    W7AMF Yeah Raft'n!

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    BUILD THREAD BEGINS ON PAGE 3 and 4!

    Im looking to get my hands on a r100rt or rs or something monoshock 1000cc, or build something from scratch (i have basically unlimited parts at my disposal, just depends on my budget really, but i want to build something with good ground clearance, 2 seater, good suspension travel, ect. im looking at starting with a late 80's or early 90s bike/frame and going from there. has anyone done a build thread anywhere (preferable an english site) that i can use for reference? TIA peeps!!!

    so far i know i want (shopping list):

    Big head/carb 1000 engine
    mono shock frame

    want to keep things as simple and as cheap as possible but not at the expense of reliability because that is my ultimate goal.

    what else should i consider??

    pics, build threads, specs anything that would help would be greatly appreciated. this will become my build thread soon!
    #1
  2. hardwaregrrl

    hardwaregrrl ignore list

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  3. Box'a'bits

    Box'a'bits In need of repair

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  4. W7AMF

    W7AMF Yeah Raft'n!

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    both are great!!!!

    anything or anyone else?

    looking to go with more of the link hardwaregrrl posted, but i want to keep it a 2 seater or have the option to go back and fourth. im not stuck trying to build a GS, just want something capable safe and reliable.
    #4
  5. Martian

    Martian Long timer

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    Something along these lines? Its basically an R100R, but with a larger front wheel, GS fender and fork brace, bash plate, and 50/50 tires.

    [​IMG]
    #5
  6. W7AMF

    W7AMF Yeah Raft'n!

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    thats about exactly what id like. maybe a LITTLE more offroad capable, but thats about dead balls on! have any other specs or a build???
    #6
  7. Martian

    Martian Long timer

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    The only real difference between this and a stock R100R is the R1100GS 19" front rim. I had it laced to the original hub so I could have a larger selection of DS tires. The fork brace and fender are stock GS parts. The rear shock is after-market, too, although it is the same size as a standard R shock. The windsheild is a rework of a Parabellum from my PD; I cut it down and reshaped it. I'd like to add a set of real DS luggage, but when DS'ing, the bags aren't usually there.

    Since the R100R and GS use many of the same components and are based on the same frame, I didn't need to make too many changes to fit my needs. My main goal was to have a bike slightly shorter than a GS that was still capable of traversing most terrain while being comfortable cruising at 80mph. I just finished a 1500 mile round trip to Texas that included rock roads, pastures, and 100mph runs up the interstate. I think it met all my goals quite well.
    #7
  8. W7AMF

    W7AMF Yeah Raft'n!

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    what is that rear swing arm called (paralever or telelever or something? i dont know the differences yet)? can it be adapted to any mono shock bike?
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  9. Airhead Wrangler

    Airhead Wrangler Long timer

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    Not easily. If you were going to install a paralever you would want the later one used on the R1100 as it doesn't have the driveshaft problems that the 1st gen paralever had. It also would allow more rear travel. Again, it would not be easy at all though to put it on a monolever frame.
    #9
  10. W7AMF

    W7AMF Yeah Raft'n!

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    gotchya, the extending a monolever is a better idea? or finding a g/s monolever?

    as well, does anyone know the rake of the frame on RS, RT, GS and g/s? Also, whats the fork rake with the tripple clamp, for the same bikes? trying to decide which forks and such to run with which frame to get a safe setup. any input would be killer! thanks!!!
    #10
  11. Beater

    Beater The Bavarian Butcher

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    When I started this quest ... that's where I landed (a monolever R80RT). However, If I had to do it again, I would find a dual shock R80 or R65. Why you ask?

    1. The dual shocks have THE WORLD of final drive choices. With the mono, you have three.
    2. A R65 can be had CHEAP. I've ridden an R65 which was very close to the output of an R80. Plenty of fun in the woods, and if you keep the RPM's up it was enough on the highway.
    3. You can still do the big forks up front, and extending the swingarm has the same issues as a mono.
    4. Don't plan on 'selling the RT faring' for a quick $300. Nobody wants them anymore.

    You will not find a G/S cheap. That's the fact, and if you did it would cost a large sum to make right. The RS's are typically more money than the RT's. The GS's are getting more rare, and you have to lengthen a monolever swingarm on those just so it fits correctly. Stephen Botcher did it ... and you need to read his page. http://www.stephenbottcher.net/index.html

    Here's his diatribe on extending a swingarm (and parelever->monolever conversion): http://www.stephenbottcher.net/BMW/paraconv.htm

    At the end of the day I would recommend several things:

    1. Don't mess with the geometry of the frame. Let a pro do that. The frames geometry is perfect for the weekend warrior. If you want a race bike, buy a KTM.
    2. Buy 'complete' parts. I was able to buy the complete front end of a DRZ400. I didn't have to cobble together brakes rotors, master cyclinders, wheels, axles, mounts ... etc.
    3. Make it work first. Don't get all neurotic about the 'perfect seat' ... find a board and tape a towel to it, and go on a ride. The longer you spend 'off' the bike' ... and not riding it ... increases the chances you won't finish it.
    4. Do ONE project at a time. Do the forks. Finish the forks. Ride it for a few days. Work out the carbs. Finish the carbs ... Ride it for a few days ... etc.

    Good luck :freaky
    #11
  12. boxerkuh

    boxerkuh Been here awhile

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    There is a difference. I own one of each.

    Monolever are single swing arm airheads from the late 80 all the way through 95. They came in R, RT and RS configuration. With the introduction of the 92 R100R and GS came the Paralever rear end, which were fore runners to the 1100 series. The only Paralever design bikes in airheads are the R and GS, the RT remained a monolever. The best way to see the difference is in color and external size. Monolever's were black, Paralever's were silver. Monolever's are much skinnier when compared to a paralever. There are also mechanical differences between the two. Monolevers have oil, paralevers are dry; in addition you can mate different rear ends to the monolever, but that is not available for paralevers.

    Hope that makes sense.

    1986 R 80RS (monolever)
    1992 R 100 R UK model (paralever)
    #12
  13. bikerfish

    bikerfish flyfishandride

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    I'll second not adapting a paralever. I have both traditional shaft and paralever boxers, the paralever assy is heavy, the u-joints fragile, and the pivot bearings need attention and service. not worth it for me. I'd stick with a traditional shaft assy, change the lube once in a while and forget about it!
    #13
  14. W7AMF

    W7AMF Yeah Raft'n!

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    THANKS FOR THE KILLER INFO! I found the stephen bottcher site today. awesome info there! your build is sweet too. im def going with a 100 (1000) because i want the extra umph for long loaded highway runs. a large bore carb and head 1000, and i have a few to choose from at work. i def dont want to mess with frame geometry, im just trying to see what the difference in rake is, so i can get as close to the GS as possible with tripple clamps, or ill do like you did and use DR or DRZ forks. good call on the complete bits!

    thanks sir! im thinking ill just buy an extended monolever then, or build one! my question is, if i extend the monolever, how do i extend the shaft whilest keep it balanced, or does it have enough slip (im assuming there is slip... haha)

    thanks!! yeah, im def going to stick with the mono shock, mono lever. maybe a dual shock if i get a good deal, then but better shocks/springs on it.

    anyone else have any suggestions? for i start putting parts together?!
    #14
  15. Beater

    Beater The Bavarian Butcher

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    PS -

    5. The RS has short handlebars. This means you would have to lengthen the cables ... all of them.
    6. The dual shock bikes can have spoke wheels. This is another reason ... The Dobber has a cast rear wheel for a reason ... BMW never made a spoke rear for a four bold final drive. Ouch. I didn't think about that one ... Go on Ebay ... spoke rears for a dual shock bike are everywhere.
    #15
  16. Beater

    Beater The Bavarian Butcher

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    Don't get fixated on the 'big bore' heads and carbs. Not worth it in my opinion ... Get the standard bore 980cc pistons and cylinders the smaller bore heads and VM32 Mikuni carbs ... It will have more more power through all of the range than the 'big bore' stuff.

    But it sounds like you should be looking for a naked R100 from 81 to 84. They are out there. These are the dual shocks with no flywheel, just clutch carrier.

    PS - My youngest daughter sends you this: :dj
    #16
  17. W7AMF

    W7AMF Yeah Raft'n!

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    why dual shock over monoshock? i dont think the final drive gear ratio availability is that big of a deal to me. i just want something decent for the highway. doesnt have to be great even. as long as it will do 80mph fairly easily while being loaded down.
    #17
  18. Airhead Wrangler

    Airhead Wrangler Long timer

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    Monolever final drives are getting tough to find. Monolever spoked hubs with remaining brake lining are approaching "hens teeth" status. You can get a 4 lug monolever and mill a later paralever GS hub to fit, but then ideally you'd have to redrill the spoke holes in the hub for a conventional rim instead of BMW's tubeless cross spoke rim.

    The dual shock parts are easier to source and you have a greater variety of final drive ratios available to you. Sustained comfortable actual 80mph (not indicated) is a bit high for the 37:11 ratio, especially for 1000cc engine. 32:10 would be about right in my mind.
    #18
  19. Beater

    Beater The Bavarian Butcher

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    What he said. :evil
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  20. W7AMF

    W7AMF Yeah Raft'n!

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    Not sure i quite understand? I know I want a spoked rear wheel at least i think, and I know I want a 17' wheel right? and a 20 or a 21" front right? spoked in the front for sure. I have about 20 mono lever final drives to choose from at work ;) my question is, can i get a spoked 17 inch wheel for the rear thats 4 lug? the G/S and r80's are 3 lug right? id also preferable like to run a disc rear, but not absolutely necessary.

    thanks!!
    #20