Trials conversions

Discussion in 'Trials' started by plane_ben, Mar 7, 2011.

  1. wilkinsonk

    wilkinsonk soup de grimace

    Joined:
    Jan 21, 2008
    Oddometer:
    959
    Location:
    Sanford, NC
    Sounds like you've got a plan, and I applaud your efforts. Do you have a jig or a frame table you are going to use to make sure everything is straight or do you have another method?
    #41
  2. plane_ben

    plane_ben Adventurer

    Joined:
    Mar 24, 2006
    Oddometer:
    56
    I have a frame jig available for when I do the steering stem. The rest I'm not to worried about. I've worked it out in my head that I'll do the engine raise before I cut the bottom of the frame off.
    #42
  3. plane_ben

    plane_ben Adventurer

    Joined:
    Mar 24, 2006
    Oddometer:
    56
    Got my engine raised 1". first shot is the bottom rear mount cut and rewelded 1" higher. You can also see the bottom rails cut off. Some fab left to tie subframe legs back to bottom cross brace.

    [​IMG]

    These are the two new brackets I made to make up the 1" raise for the rear top engine mount.

    [​IMG]

    [​IMG]

    The front engine mount, I was able to use the stock mount plates. I just turned them up side down and reversed sides. then I cut the down tube in two places. Bent the upper cut towards the engine, and the lower cut back towards the front wheel. Then welded up. I will strenghten those areas with a diamond patch over each weld.

    [​IMG]

    This last pic is the clearancing of the top frame rail to clear the rear valve cover. I will blend out and the shape corners and add a fill piece.

    [​IMG]

    After all this is buttoned up and pretty, I'll tackle the rake on the steering stem.
    #43
  4. PSchrauber

    PSchrauber Been here awhile

    Joined:
    Jan 3, 2011
    Oddometer:
    999
    Location:
    Summer: Kemiƶ, Finland; Winter: North Germany
    This is not a complete conversion more a modification but fit here too I thing.

    I could get an old pair of betor forks from France:
    [​IMG]

    After deassembling there was some wear and the stanchions where a little bit pittet and not perfect straight anymore:

    [​IMG]


    The stancions where straightened again and got a new hard chrome plating.

    I then got special fork caps and progressive fork springs from Spain:
    [​IMG]

    The fork caps are adjustable:
    [​IMG]

    The lower fork tubes where lightened:
    [​IMG]


    Then I replaced some of the worn out shims and bushings too:
    [​IMG]

    And reassambled the forks, the main difference is to the standard one which are blue I lost about pound of weight because I can now use
    modern front fender brackets aut of alloy instead of the steel once.
    [​IMG]

    [​IMG]

    Then some paint:
    [​IMG]

    Test assembly:
    [​IMG]

    [​IMG]
    #44
  5. lamotovita

    lamotovita Ageing Adventurer

    Joined:
    Oct 5, 2007
    Oddometer:
    1,917
    Location:
    WA/AZ, USA
    Wow, I've got fork envy!
    Are the fork brace mounts custom or from another bike?
    #45
  6. PSchrauber

    PSchrauber Been here awhile

    Joined:
    Jan 3, 2011
    Oddometer:
    999
    Location:
    Summer: Kemiƶ, Finland; Winter: North Germany
    Nothing to be envy for, actually I'am also a little bit impressed that it
    turned out so well, I think I've got a fork flash and this mod turned into a pimp my Bultaco ride. :rofl

    The mounts are from older GasGas, you can also take Sherco's from befor
    2000. You have to get them first, just to know how much you have to turn
    down the lower fork tubes.

    I was inspired by the PUMA or Vasquez Bultacos, but these bikes where mostly rebuild with Paoli or other I do not know where they come from forks, (which are and will be far better too). I wanted to use the old standard Betor, these are cheap and easy to get.

    I took a pair for a low price, now I would not try to get the cheapest, better to get one which is in a very good technical condition.

    Without the corrections and chromeplating of the stanchions it is a really
    priceworthy modification and a good fork from a newer bike of the end 80' or 90's is as twice as expensive.
    #46
  7. plane_ben

    plane_ben Adventurer

    Joined:
    Mar 24, 2006
    Oddometer:
    56
    Got alittle farther along with my trials mods. I made the subframe much skinnier. After looking at the Peter Gaunt bike for a few more hours, I realized how they did it. First was to cut off outer down support from the shock mount to the outer swing arm mount tab. I refitted the down support by shortening the required amount and rewelded onto the top corners of the rear engine mount.

    [​IMG]

    [​IMG]

    Then I made two plates for either side and located the holes for the swingarm bolt, and used some smaller dia. tube to slide into the rear engine mount cross tube. These I welded to the bottom of the side plates. I also welded the footpegs on and made the rear brake lever pivot.

    [​IMG]

    [​IMG]

    [​IMG]

    Having lots of fun with this project. Next on the agenda is shorting the swingarm 1". Then I'll tackle the biggy, front fork rake.:wink:
    #47
  8. plane_ben

    plane_ben Adventurer

    Joined:
    Mar 24, 2006
    Oddometer:
    56
    As for badass trials conversions, this one takes the prize in my eyes. Totally cool!

    [​IMG]
    #48
  9. roadholder

    roadholder Long timer

    Joined:
    Jul 28, 2007
    Oddometer:
    2,688
    Location:
    Ottawa, Canada
    OK...what is it?
    Honda engine. Frame?
    #49
  10. plane_ben

    plane_ben Adventurer

    Joined:
    Mar 24, 2006
    Oddometer:
    56
    #50
  11. plane_ben

    plane_ben Adventurer

    Joined:
    Mar 24, 2006
    Oddometer:
    56
    Finished up the steering stem angle mod. Came out straight as an arrow.:wink:

    [​IMG]

    [​IMG]

    [​IMG]
    #51
  12. Brunow - 007

    Brunow - 007 Bantam Fever

    Joined:
    Oct 26, 2009
    Oddometer:
    313
    Some great posts here! Nice! :D
    #52
  13. Pete-NZ

    Pete-NZ Been here awhile

    Joined:
    May 8, 2011
    Oddometer:
    985
    Giving me ideas..:clap
    As if I need another project...
    This really isn't a conversion
    Other than converting a pile of
    bits into a trials bike....:huh
    So after a hunt though the storage
    /crap shed.. well I could build a trials
    bike from this:rofl
    one complete single shock rear end/
    forks,clamps from a Chinese Shinray 200.
    Motor.. well after a hunt around for a used one
    I came across these...NO laughing..found a out fit
    that was all but giving away these new chinese 125cc
    Honda copys.. 4 speed box ,auto clutch power houses :lol3.
    So I ordered one:huh..
    managed to flog a pic from this site of the specs..
    rake/trail/wheel base etc of a gasgas ..

    Now 1st to build a jig to bolt all the main componets in
    at the right hights / angles etc.. then build a frame
    around them..sounds easy when yer say it fast..:wink:

    just lucky I have more toys in the shop than yer can
    poke a stick at....lathe / mill / welders / plasma

    It will give my boy 9 and me a some thing to do on wet days..

    Attached Files:

    #53
  14. plane_ben

    plane_ben Adventurer

    Joined:
    Mar 24, 2006
    Oddometer:
    56
    Awesome, we need some more action on this thread.:clap
    #54
  15. Pete-NZ

    Pete-NZ Been here awhile

    Joined:
    May 8, 2011
    Oddometer:
    985

    The motor turned up ....
    looking at it...I think
    the best aproce is to make
    the engine plates & set the
    swing arm up on them..Prob
    the easyest way to get it all
    alined....

    i think when the build starts I
    mite start a new thread for it...
    "with smaller pics"

    pete

    Attached Files:

    #55
  16. Mythic State Rider

    Mythic State Rider Adventurer

    Joined:
    May 8, 2010
    Oddometer:
    20
    Ben & Pete, is there any progress to report on your builds?
    #56
  17. Pete-NZ

    Pete-NZ Been here awhile

    Joined:
    May 8, 2011
    Oddometer:
    985
    #57
  18. plane_ben

    plane_ben Adventurer

    Joined:
    Mar 24, 2006
    Oddometer:
    56
    My project is on hold for awhile. Need to get my '58 VW van on the road.
    #58
  19. plane_ben

    plane_ben Adventurer

    Joined:
    Mar 24, 2006
    Oddometer:
    56
    Pulling this project out of moth balls. Just finished up a Yamaha XS650. Updates soon.
    #59
  20. wb22rules

    wb22rules Bourbon Tester

    Joined:
    Jan 30, 2012
    Oddometer:
    206
    Location:
    Central VA
    :clap
    #60