The Air Cooled Monoshock Thread

Discussion in 'Trials' started by Brewtus, Feb 19, 2018.

  1. Ymirtrials

    Ymirtrials Long timer Supporter

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    Can’t quite make out the stickers on the fender.....:hmmmmm
  2. Brewtus

    Brewtus Buffoonery, Inc.

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    20190919_130306.jpg

    '80's Italian for "cool stuff"??

    Along with....

    20190919_130331~2.jpg

    For the reverse kickstarter? Because it rolls backwards nicely (not against the rules back then) ? :dunno

    :lol3
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  3. Ymirtrials

    Ymirtrials Long timer Supporter

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    I gotta get me some of that reverse control!!!!
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  4. Twin-shocker

    Twin-shocker Long timer

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    "Reverse Control" forks were the first cartridge type forks ever to be installed on a production trials machine. If properly serviced with the correct oil they still work really well today and are far better than any damper rod type production fork.
  5. Brewtus

    Brewtus Buffoonery, Inc.

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    Yeah, shouldn't have stolen a parking lot ride on @motobene's works Fantic.....

    20191116_165725.jpg

    Man that thing works nice....
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  6. motobene

    motobene Motoing for 49 years Supporter

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    A still photo of the spoiling process :-)
    IMG_20191116_165552.jpg
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  7. motobene

    motobene Motoing for 49 years Supporter

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    And the latest little project was taking well used side stand (bashed and warped) and fitting it to the Fantic.

    I abandoned the original when the bottom two threads in the swingarm (M6) stripped out. Fool me! Instead of fixing it in 1991 I gave the side stand away. Offing 1-pound side stands on 190-pound bikes was a weird cultural phenom then....

    Four hours of fab work and threading 1/4-28 in the bottom front hole and 5/16-24 in the bottom back hole got me back to being able to park the thing without having to find something to lean the bike against. A good old ride just got a wee better!
    IMG_20191116_145713.jpg
    IMG_20191115_163558.jpg
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  8. motobene

    motobene Motoing for 49 years Supporter

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    IMG_20191119_125536.jpg Newsflash!

    The kick stand stop boss though not abused managed to mush its way to over center. The washer foot is no longer flat to the floor.

    It took a couple of days to mash and angle the stand forward. One more work session will be required to get the bloody thing right. Thankfully I don't have to demount the mount! I expect something to go pfft when making a bunch of changes. Oh well. Shouldn't take more than a hour to make it robust for the long term.
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  9. Brewtus

    Brewtus Buffoonery, Inc.

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    Just can't have nice things.... :lol3
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  10. motobene

    motobene Motoing for 49 years Supporter

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    Those kick stands had a certain shitty element to them to begin with so working out all the details will take more than one iteration. Problem is it will sit there probably for a long time before I can get back to it.
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  11. Runaway Train

    Runaway Train The Left-Right Tourer

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    What’s with the forward foot peg on the same side as the shifter?
  12. lineaway

    lineaway Long timer

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    He is missing a leg, that the brake pedal.
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  13. PSchrauber

    PSchrauber Long timer

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    The upper end is at your DIY slidestand the steel tube isn't it.

    If so it was just a matter of time that the sidestand "leg" has wandered more then you want.

    You should have made thr upper part out of a massive steel.part, this can't be bend away like the tube did.

    My personal 2 Cent:
    You might fill up the hole in the tube by welding, to strenghten the upper part so it can better resist the force.
  14. Slow Joe

    Slow Joe Yep, that's me

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    Hello,
    Dreaded oil question.... Bike in question is a 94 Beta Alp 240.
    I haven't had a two stroke motorcycle since motocross bikes in the mid 80s and I'm sure things have changed, a bunch since then. In researching the webs it looks like the popular choices for air cooled trials are semi synthetics at 50:1 or full synthetics at 70:1. Is this close? I know jetting is going to change depending on mixture rate.
    I have no way to ask the previous owner what he was running in the bike.

    Thank you,
    Joe
  15. heffergm

    heffergm Been here awhile

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  16. SherpaT

    SherpaT Adventurer

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    Are you trail riding, or trials riding? Beta UK shows 70:1 with semi-synthetic for the TR34, but not sure what era that was written. I’m running 64:1 (easy 2 oz. per gallon) Maxima K2 synthetic in my TR34, and it’s running clean, with no splooge in the exhaust. If you’re trail riding, at higher throttle, I probably wouldn’t run leaner than 50:1 though.

    https://beta-uk.com/index.php/component/content/article/32-1989-bikes/33-1989-trials-models
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  17. Chad M

    Chad M 14880

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  18. tomatoe333

    tomatoe333 Long timer

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    I ran 70:1 full synthetic in my 93 SuperTrial (exactly the same bike). 70ml of oil into 5 liters of gas (there was a convenient line on the side of the gas can). I used Amsoil Interceptor, but any good synthetic pre-mix oil will work fine in it. I even ran 80:1 when I ran out of gas at an event and had to use some out of a friend's jug. Jetting won't change appreciably with that lean of an oil mix. 50:1 will just make the bike smoke, and clog up the un-repackable muffler that much faster.

    Avoid gasoline with ethanol in it like the plague. The old Beta fuel tanks would swell up to the point where you couldn't unscrew the gas cap if they got 10% ethanol in them. The tank will eventually recover if you put plain gas in it, but it takes some time. The engine seemed to ping more on the gas with ethanol in it as well, despite being higher octane than the ethanol free.
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  19. jonnyc21

    jonnyc21 Trials Ninja

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    Note on the non-ethanal fuel. If you really can't find any quality fuel I have heard a number of people improve things by using caswell tank sealer to help prevent the ethanal from cauing issues with fuel tanks... Might be worth a look.

    Hope you don't have to resort to that level but just in case.
  20. Junglejeff1

    Junglejeff1 Long timer

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    A important thing is do you have a a plated cylinder (most likely)or a iron liner.plated much slicker and tougher. Another consideration is trial or trail.If trials riding go 80:1 and trail 50:1 as it helps protect at high revs but will booger your exhaust in trials.High revs and higher speeds create way more heat in exhaust that help burn off excess oil.Engines at run at high rpm last longer with more oil because they need the extra film strength. After almost 30 years of offroad and mx I found to run 125,s at 40:1 and 250,s at 50:1 it helps keep the parts count lower.For trials 80:1 is real safe.I just tore down a 94 fantic that was abused and never torn down.It was used only for trials and spent its life on 80:1.Top end and crank are almost like new.If you ever ride that bike down a road for a couple miles fast you will most likely think it's on fire when you stop from the acidic smoke pouring out the exhaust. Gives a good indication of how much oil is not being used even at 80:1 on a trials bike.I don't use my GG for trails as it is hard on the bike(just don't have the suspension. 20191214_192845.jpg travel needed)
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