JTH's HD 883 Dual Sport'ster conversion

Discussion in 'Some Assembly Required' started by JimmyTheHog, Feb 4, 2011.

  1. kellymac530

    kellymac530 motorcycle addict

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    Hey Boat Puller....note the front wheel size..... :rofl:D

    A serious adventure heavyweight bike with a dirt biased design and he is running a 21" front....Im just sayin. :freaky

    Hey JTH, I love what you are doing here. I love some "different" ideas and OOTB thinking. I would love to see this bike in person and comb over the details. Just beautiful work and concept.

    My best riding buddy is a Harley guy but wants to get into ADV style riding and exploring with me so I sent him this thread to show him he could have BOTH.

    I would never want to throw my opinion in on such a great build but if you would like an idea I see may help on this build....stop reading if not :cry

    Have you considered or looked at running a sprocket brake on the rear. You may save weight and compress some stuff. I personally have never been a big fan of that huge rear caliper and mount system on Harleys, maybe going to a smaller 4 piston Brembo or similar and then make a bracket to mount it on the drive sprocket like some chopper guys have done could keep braking power or possibly even increase it and cut a couple of pounds of unsprung weight.

    Here are a few ideas just to make you think about it a bit...not telling you what to do at all, just thinking outloud and throwing it out there.
    http://www.ebay.com/sch/i.html?_nkw=sprocket+brake
  2. kellymac530

    kellymac530 motorcycle addict

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    JTH,
    I forgot to ask something, I went back and re read the thread and I must have missed something, I am an idiot, but what was the reason you changed from the single left side shock you intended when you designed the schwing arm to the verticle dual shock design you are now running?


    It is probably there and I missed it, but direct me to a page to see the info if possible.
    :clap
  3. JimmyTheHog

    JimmyTheHog Low Speed Adventurer

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    Thanks for the input and tips everyone.

    For the rear brake caliper, i hear you! It is big and heavy. The reason i kept it this way was to keep the stock HD mounting. This way It will fit other aftermarket caliper set-ups which I'll probably do someday. But until then, its stock HD that actually works pretty well for stopping power and the HD shops can replace or work on it with stock parts.

    For the FI models, an external pump would seem to make sense if theres room to locate it.

    I opted for the dual shocks for a few reasons - to maintain the stock frame (with only minor mods), didnt want any uneven swingarm twisting and related poor handling characteristics (considering where the shock would have been mounted, i think there would have been some considerable redesign of the swingarm to address the stresses and stiffness requirements), and I liked the old school look of twin shocks since the bike is a mix of new and old.
  4. bk brkr baker

    bk brkr baker Long timer

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    JTH , I've following from the start and it's been a beautiful trip.
    The bike looks wonderful.Each piece is well made and thoughtfully done.
    I may have missed it somewhere, but have you put it on a scale yet ?
  5. JimmyTheHog

    JimmyTheHog Low Speed Adventurer

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    Yes, I have weighed it - its 474 lbs with ~1 gal of gas in the tank.
  6. kellymac530

    kellymac530 motorcycle addict

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    Glad I did not offend with my thoughts. Good idea keeping it service able at HD dealers for long distance travel purposses.
    I was purely thinking of weight.

    I agree on the shocks being a cool old school style and if they work good then all is good. I was purely curious as to the change reason, makes good sense especially since you thinking or even trying to market this as a kit, or at least parts of a kit. The good old KISS mentality. (Not that YOU are stupid....refereing to my self there)

    Great stuff here Jimmy, thanks for the detailed thread. That is a really good weight for a big twin ADV bike. I think I want one... :clap
    At the very least, I want my buddy to build one so I can have him Beta test it. :D
  7. kellymac530

    kellymac530 motorcycle addict

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    One more quick question if I may,
    It looks like you are running a stock KTM 2 piston front brake caliper on an extension bracket and a 320mm rotor, is that correct?

    How do you feel it works on a close to 500# bike?

    I am prepping to start a bike build and collecting parts and I have some negative input on my plans that my brake ideas are in no way enough, but I think they will be fine. I have a respectable inmate who builds alot of bikes insisting that not running a dual disc set up off of a big KTM twin will not be enough but I see alot of guys running the setup you have and see no big complaints.

    Are you a heavy front brake user or a more typical HD rider and tend to use more rear?

    I have raced MX for 40+ years and am a BIG front braker, My motto is "front brakes stop a motorcycle, rear wheel steers a motorcycle"....over simplified of course, but useable advice.

    Thanks again JTH.
  8. JimmyTheHog

    JimmyTheHog Low Speed Adventurer

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    KMac - Correct on the front brake. Its a KTM 2-pistion Brembo from a 525EXC, 320mm rotor, and extension bracket. Braided SST brake line and an Oberon adjustable brake lever on the stock Sportster master cylinder running DOT5.0 silicone. Im forgetting what brake pad material i have, but what ever stock KTM uses, thats it.

    As far as braking power - for me, its adequate with this setup, but im a light braker. Having the adjustable lever made it better to get the max squeeze for my hand size. That being said, Ive had GS's, HP2's, 950SE, and 950/990 Adv's and all brake better than this setup. For offroad riding, i actually like it not being too grabby though. I crashed an HP2 in the dirt from a too grabby front brake once. For the on-road, i would actually like a bit more stopping power, but as i said - its adequate and have had to brake hard a few times and it gets the job done no problem. It does stop when the lever is pulled. Just takes a bit more pull force. The 320mm rotor was the big difference.

    Im going to try a different pad material and that may be the ticket to a bit better on-road braking. I'll post when i do it.

    If youre a hard front braker and like that - this setup will probably feel underbraked for you - unless the different pad material makes a difference.
  9. Roadracer_Al

    Roadracer_Al louder, louder, louder!

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    Are you planning to have the tank shaped in steel?
  10. JimmyTheHog

    JimmyTheHog Low Speed Adventurer

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    No on the steel. The primary plan is to make it plastic.
  11. Roadracer_Al

    Roadracer_Al louder, louder, louder!

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    Plastic like FRP, or plastic like rotomolded dirt bike tanks?

    If the latter, I'd be interested to know costs and a source.

    That kind of information is just good to have, you know, just in case. :clap
  12. JimmyTheHog

    JimmyTheHog Low Speed Adventurer

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    Rotomolded XLPE. Im working on selecting the right supplier now, so cant disclose anything yet.
  13. kellymac530

    kellymac530 motorcycle addict

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    Thanx a ton for your reply Jimmy.
    Very cool of you to take time to answer my question while you are still working on this great machine.
    I am pounding out some details for a build myself and an inmate here has given me some great advice on brakes and getting to some other ideas is very helpful.
  14. JimmyTheHog

    JimmyTheHog Low Speed Adventurer

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    Happy Holidays everyone!

    New projects for 2013 are already in progress:
    - 6 gal gas tank - Aluminum prototype to start, then plastic to follow
    - Crash bars
    - Triple Clamps
    - ???



    CRASH BARS: To go along with the larger gas tank, I'll be adding a crash bar to protect the tank and petcocks in case of a low side fall and also to mount some new LED flood lights.

    [​IMG]



    [​IMG]

    [​IMG]




    TRIPLE CLAMPS: Triple Clamps design is close to done. These are stronger than the ones im using now and will allow for more turning radius as the clamps have been moved to the front and provide more clearance to the frame.

    [​IMG]

    [​IMG]
  15. MitchG

    MitchG Iron Collector

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    Keep up the good work Jim! You've got at least one victim in me...
  16. DRjoe

    DRjoe Long timer

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    your pretty handy cad then
  17. WhicheverAnyWayCan

    WhicheverAnyWayCan Deaf Biker

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    JimmyTheHog,

    You don't have to buy your Triple Tree if buying your fuel tank? I was hoping to stay with my own Triple Tree while using your fuel tank.

    Thanks!
  18. JimmyTheHog

    JimmyTheHog Low Speed Adventurer

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    No, you dont need to. The stock KTM 525 triple clamps or the Applied Racing (for KTM) triple clamps will work with the tank as is. For others clamps, i would need to check the dimensions, but the tank has generous clearance for the forks and clamps, so unless youre using something really wide, they should fit.

    These new triple clamps will be stronger & stiffer for the increased weight of the Sportster and give a bit more turning radius now that the new tank allows for that. Ive also integrated the Sportster rubber handlebar dampers into the bar risers - keeps motor vibration to the hands down to a minimun.
  19. boatpuller

    boatpuller Been here awhile

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    What forks will your triple tree accommodate?

    (If that is a silly question, please excuse me. I've never changed changed or researched forks before, but plan to in this upcoming project.)
  20. Luke

    Luke GPoET&P

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    Are you (or have you considered) putting steering damper mounts on the triple clamp? It should be a pretty easy addition, just a couple of threaded holes. It would work much better than a bracket that gets added on afterwards, especially if the bracket is attached to the handlebar side of the rubber mount.

    I have no idea if your bike would be helped much by a steering damper, but lots of people like them on other bikes.