Big Wheel Dual Range dune climbing desert bike

Discussion in 'Some Assembly Required' started by WILL_S, Feb 19, 2015.

  1. WILL_S

    WILL_S OUTLAW POSTIE 001

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    Yeah i don't know,but really for economy a 125 dual range that gets 30+kpl would be a bonus.
    Carry less fuel and weight would be a win.
    Whats that would be the hardest bit if you were riding a postie out there coxy?
    Then i can improve on it
    #41
  2. GR0NK

    GR0NK Got some screws loose!

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    What's canning?



    Sean :bmwrider
    #42
  3. WILL_S

    WILL_S OUTLAW POSTIE 001

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    Starring wiggywildwildwest :drink
    #43
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  4. WILL_S

    WILL_S OUTLAW POSTIE 001

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    Lots of sidetracking but inspiration has turned up in the shed
    Been playing motors,take atc/ct cases and throw one a 250 barrel in the lathe and slap on a head .
    If this combo works there might not be a need for dual range

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    Slap on a copy head with big valves and roller bearings on the cam

    [​IMG]
    #44
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  5. WILL_S

    WILL_S OUTLAW POSTIE 001

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    Now for the inspiration
    These legends turned up in me shed
    Going to give their bikes some love before they head of across the country
    Just looking at Jocks setup gets the creative juices flowing


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    #45
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  6. GR0NK

    GR0NK Got some screws loose!

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    Wait, what?!!! :scratch

    Does this setup still use the stock crank and rod or some parts from the bigger motors?

    Is that an actual IHI RHB31 or a clone?

    Shit just got real now Will! :super




    Sean :bmwrider
    #46
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  7. WILL_S

    WILL_S OUTLAW POSTIE 001

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    Um,couple of ways to do it
    use my helm 58mm stroker 110 crank
    .Atc125 crank+ short barrel xl barrel
    or atc125 crank +3mm offset pin
    Ct110 crank +5mm offset pin and atc125 rod and barrel height adjusted
    or.....
    haven't decided on final combo yet

    That other IHI bit i thought you were talking in code lol
    Couldn't tell you it came in a nicely packed box, will have to investigate more but they have been used on the mini motors is what i was told
    #47
  8. GR0NK

    GR0NK Got some screws loose!

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    I'm just curious if those rods are strong enough to hold a 250cc slug? I know it's not a high RPM race motor but I would be worried about one letting go in the middle of nowhere.



    Sean :bmwrider
    #48
  9. WILL_S

    WILL_S OUTLAW POSTIE 001

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    Should be right
    The 250 only went up 1mm outside dia for big end bearing ,big end pin same size as 110/125 ,on some models.
    Looked at heaps of rod dimensions
    I will only get 200cc out of it
    It would be more likely the clutch causing issues pushing big tyres under load up a dune.
    There will be plenty of testing close to home before i hit the remote
    #49
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  10. WILL_S

    WILL_S OUTLAW POSTIE 001

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    Ok front end time
    Got a couple of atc triples 250r and 350x i think .Ones raked so no good but the other set are non raked.
    Got to press the stem out and grab a ct110 stem out of a old set of yamaha ag triples that were modded to fit the postie and do a bit of machining.
    The ct stem needs to be lengthened and have the atc diameter added to the bottom to get a nice press fit.

    Going
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    Gone
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    Donor
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    The plan
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    #50
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  11. WILL_S

    WILL_S OUTLAW POSTIE 001

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    Machining time

    Atc stem gets cut to sit level with the base of the bottom triple,then bored to be a press fit onto the ct stem.

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    The top clamp hole for the stem to pass through is larger than the ct stem diameter.
    A little sleeve snugs it up

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    #51
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  12. GR0NK

    GR0NK Got some screws loose!

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    This is coming along nicely. :thumb

    So what idea did you get from my BigFat build?




    Sean :bmwrider
    #52
  13. WILL_S

    WILL_S OUTLAW POSTIE 001

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    Bigger tyres and jackshaft,but i haven't got to that bit yet :drink
    Oh and a bit of motivation
    #53
  14. DRjoe

    DRjoe Long timer

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    Don't forget the new plan will.
    The V twin with cvt is going to be a dune destroyer.
    #54
  15. WILL_S

    WILL_S OUTLAW POSTIE 001

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    Ha ,who knows what this thing will end up running
    Might knock up a couple of swingers and you can v twin fat tyre yours
    Nutz
    #55
  16. WILL_S

    WILL_S OUTLAW POSTIE 001

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    Front hub turned up today.
    Can run rims with 110 pcd
    Some spacers and a adapter to run a bigger disc will be needed .
    Torn between convention forks and usd
    Got the gpx black label usd on my postie and the are brilliant .
    Looks like i can mod some triples off a cruiser and fit the usd legs in and run a 7" front tyre.


    20160520_172456.jpg 20160520_172441.jpg
    #56
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  17. GR0NK

    GR0NK Got some screws loose!

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    I know your terrain is different but here's my take.
    If the machine is going to get used (abused) in really rough terrain and there's no performance advantage to running USD forks then run conventionals. Take for instance my BigFat, it will be running through water, rocks, trees and swamp. I'm glad it has conventional forks as the lowers are more durable in that kind of usage. If you're only going to see desert type conditions it might not matter so much.



    Sean :bmwrider
    #57
  18. WILL_S

    WILL_S OUTLAW POSTIE 001

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    Slap it together with whats laying around
    Got a 18x9.5-8 tyre rim combo which fits the hub that turned up.
    The plan is to use at least a 21x7-10.
    Digging the look of the small tyre 20160522_144638.jpg 2016-05-22 14.48.29.jpg 20160522_144625.jpg
    #58
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  19. wiggywildwildwest

    wiggywildwildwest cranky bugger

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    looking good will. another thing to consider is reliability. just playing devils advocate here. what about a 125 donk? i'm sure you've discussed it at length with jock, but when i talked to him he reckoned the big tyres made it easy. maybe you don't need heaps of powerz on this bike?
    #59
  20. WILL_S

    WILL_S OUTLAW POSTIE 001

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    Yeah mate
    Been thinking about that a bit
    Really don't need speed just economy and reliability
    My 125 is a 150
    Got the 110 dual range i could chuck a crank in
    Like the idea of putting along having a good look around.
    #60