Trials Bike Build/conversion?

Discussion in 'Trials' started by rizzer, Jun 23, 2011.

  1. rizzer

    rizzer no longer bikeless

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    FUUUCK!!! I just lost my front forks!!! :cry

    kept it in the trunk of my car and when the wife went to the car wash, she took it down and left it there...and this was about a month ago so it's long gone now :(:

    NEVER trust the missus with your bike parts!!!!!!
    #61
  2. djones745

    djones745 they call me lawndart for a reason...

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    damn that sucks! I don't leave the missus alone with any of the herd- next thing I know they'd be on the front lawn with 'free to good home' signs on 'em!:eek1
    #62
  3. loncin

    loncin n00b

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    Hi guys what a great site,i have just built a trials bike special, yamaha DT chopped frame,loncin big bore 110cc pit bike engine, folks shortened 3 inches, swinging arm lengthened 2.5 inches to tale 400x18 tyre,52 tooth rear sprocket, but may have to go bigger, had the first ride today & its very good just a few bits to fettle,
    #63
  4. loncin

    loncin n00b

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  5. LucasLeader

    LucasLeader Been here awhile

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    Cutting the down tube out of the frame probably isn't a good idea. I don't know if the engineers design the frame to be strong enough without the down tube and then add it just for motor mounting points and protection, but probably not.
    #65
  6. loncin

    loncin n00b

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    The top tube is38mm, extra plates on the yoke suport and just under the tanks and extra 25 tube from the cut off point to the back under the seat, you would have to put a truck on it to bend it, and its only for light trials work,
    #66
  7. LucasLeader

    LucasLeader Been here awhile

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    Oh good. Sounds like you have it covered.
    #67
  8. motojunky

    motojunky Professional Idiot

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    Interesting, thanks for sharing. I'm curious - why not use the original DT engine?

    What is the total weight of the finished project?
    #68
  9. loncin

    loncin n00b

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    the original dt was only 50 cc and automatic so not much good, the final weight i dont know yet as i am still doing bits to it,next job is to move the foot pegs back, nearer to the rear wheel , and also a bigger rear sprocket gone from 38 to 52, now going to try 64 try and get it softer and slower still got loads of torque,
    #69
  10. loncin

    loncin n00b

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    Well got the foot pegs moved back and up so it more stable now, new rear sprocket on it way 64 tooth this time so should take some of the snap out of it and be alot slower,
    #70
  11. rizzer

    rizzer no longer bikeless

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    Sorry to bring this thread back from the dead...but I'm FINALLY starting to build one...good to see the enthusiasm, so let's not let this thread sink :)

    Hi Loncin! Could you post pics of your bike? would be great to learn from what you've accomplished.

    EDIT: Sorry I didn't realize there was a link to your photobucket...nice build man! any action pics? :D
    #71
  12. B1

    B1 Carbon-based bipedal

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    i bought this chinese bike a few years back for $700 which a guy had converted for trials and even added a sidecar.

    only got three rides on it then sold it as no one i knew back then was interested in trials riding. he did a pretty good job and it was probably better than most twin shocks but not as good as the early mono shock models. extremely economical and had an electric start to boot! his build thread is here.

    [​IMG]

    [​IMG]

    this was the original bike, an x-moto xb31 mini bike.

    [​IMG]
    #72
  13. rizzer

    rizzer no longer bikeless

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    Thanks B1! I'm also going into the "chop" route. I'm trying to spend the least I can and fabricate as little as possible.

    Chopped the subframe shorter and didn't fabricate a new lower subframe. I hope it wasn't a bad decision...and it'll still be a twin shock as the original donor bike is.

    18-21 excel rims I had collecting dust. a Yamaha DT tank, that I hope it isn't too big, might chop it down later if it is. Or maybe a couple of rounds with a hammer might do.

    But for the time being it'll be on motocross knobbies that I had laying around. can't cough out the cash for new trials tires just yet.

    No pics for now, but when I do, I'll post them up.

    BTW, I had to find ways to get approval from the wife since I just picked up 3 bikes last year. She didn't like the idea of spending so much on bikes that don't get ridden much. So I sold one bike, and I told her "I'm gonna build a trials bike for you!" So far, the plan is working great. lights are green and she's even enthusiastic :D
    #73
  14. motobene

    motobene Motoing for 51 years

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    Love messing around with and building hybrids. Have done that several times. It's fun. But if you haven't spent much time on a trials bike and just want to make one out of, say a small dual sport, you are skipping a step. This is why some above said to just get a trials bike.

    Significant time on a trials bike, pushing at learning techniques, will change how you think and how your ride any bike. It will forever alter your preferences.

    Once you have built experience on a trials bike, it will make you much better and setting up and riding ANY motorcycle. You'll be able to go up and over things without a lot of throttle, spastic clutch, ditch digging, mayhem and crashing. Your fast-riding buddies will scratch their heads and say, "How'd you do that?"
    #74
  15. rizzer

    rizzer no longer bikeless

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    Yea, I caught that point :(:
    But for the time being, building a cheapo project is all I got. believe me, I'm tempted to pick up a proper trials bike, but the price is just outrageous...Gas gas TXT's are around $13-15 grand down here. Used ones go for at least $5 grand. Ossa just came on shore, but I doubt it'd be any cheaper...none of the japs makers sell trials bikes out here... There is the Gasgas Randonne though, but I dunno, I just think I'll grow out of it too soon...It happened to a couple of enduro bike projects/purchases I've done in the past.

    So from those options, I'll settle for a frankenstein bike.

    Who knows, my luck might turn out and I'll have THAT much cash to burn...amen :D
    #75
  16. rizzer

    rizzer no longer bikeless

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    some Indonesian "homemade" trials bikes I found on google.
    [​IMG]
    [​IMG]
    [​IMG]
    one serious lookin custom frame!
    [​IMG]
    #76
  17. motobene

    motobene Motoing for 51 years

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    Indonesia. I didn't catch that earlier. Bikes are really over priced there. Sounds like Brazil, having nuts import taxes.

    A bike in hand is for sure better than not riding a dream bike!
    #77
  18. rizzer

    rizzer no longer bikeless

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    hahaha I wish! :p
    What I meant was if I decided on getting another bike, I'd lose TONS of cash selling a used Randonne...can't risk that

    Yep, local market is tightly protected with high taxes. A Sportster 883 Low is around $25 grand here :huh

    And regulations on registering a bike weren't well thought out either. My husky WR250 for example, was imported legally and went through all the tight bureaucracies (and taxes, sadly), but then it failed the emission test cause the regulations on emission is only classed by engine displacements. My bike is a 2 stroke, but it had to pass 4 stroke standards. long story short, it isn't street legal now :cry
    #78
  19. rizzer

    rizzer no longer bikeless

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    [​IMG]

    progress so far...painted frame

    I hope I won't regret deciding not to drop the seat
    #79
  20. XR200R

    XR200R Homemade

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    Hello,
    When I was younger I put a Honda 160 twin engine in a CL90 frame with a big rear sprocket and wish I still had it.

    Next, I cut down a Yamaha DT360, using a gas tank from a Yamaha 80, big rear sprocket, re-raked steering head, cut steering stops, rearset pegs, custom exhaust and shortened swing arm. It would go where the new TY350's were going, but of course I had to work harder to get there.

    My present ride is a stripped Honda XR200R with XR80 gas tank, reraked steering head, shortened swingarm, narrowed frame, rearset footpegs, custom exhaust, cut steering stops, big sprocket and direct-acting monoshock. Yes, it's the twin-carb version. I added a butterfly choke to make starting easy. I strongly recommend starting with the single-carburetor motor if you want to do a conversion, because the twin-carb set-up is wide.

    It is a good woods bike and tough as a rock.

    Attached Files:

    #80
    DyrWolf and REALGRAVEROBBER like this.