From CA, fist post her

Discussion in 'Introduce Yourself' started by ragdolldude, May 30, 2016.

  1. ragdolldude

    ragdolldude Member

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    I'll be 70 soon, and found your site recently. I made diy go karts and 2 minibikes back in the 60's. But I liked the belt drive of my first mini bike, made on a 20 in inch bike frame, Power Products 2 stroke motor, and a V-plex clutch. I just found a NOS V-plex clutch and it's coming this week. I want to use a Honda GX50 engine on either a beach cruiser frame or one of the newer aluminum frames with built in gas tank. V-plex pulley is on starts out with a pulley slightly larger than 1 inch and closes V belt gap to produce about a 2 1/4 or so pulley at higher rpm. It's an A belt clutch and I was considering the Whizzer 15 inch sheave for the rear wheel. This will be on a 26 inch bike. Will this gearing be ok, with this "expandable pulley" clutch. Thanks
     
  2. curtisfox

    curtisfox Active Member

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    Welcome aboard. I to had that clutch when i was a kid,hard to find now. I have 2 used ones, i plan on using. I will be using a old briggs. You may have to run a jackshaft to get the gearing right, or even a 24" rim for a pulley................Curt
     
  3. ragdolldude

    ragdolldude Member

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    I noted there are 20 inch pulleys available too, if sheave needs to be bigger. I planned on taking one of those sprocket mounts that clamp around the axle housing on rear, bolt on larger chain and mount a sheave or larger pulley to a plate that can be bolted, welded or brazed to a larger sprocket. I'm trying to make drive train from clutch to sheave without using a jackshaft, if at all possible. I recall using jackshaft on one mini bike and one kart, and seated an extra 4-5 inch pulley on shaft. Found appropriate sized belt, used cut short piece of aluminum C channel, put on end of pulley and put bolt through channel. One end bolted to chassis, and other end to a cable, actuated with a bike brake lever, that would pull on vbelt around extra pulley. Worked pretty well. All my projects were made with paper route money, so funds were pretty lows. Gas lever for my 20" low rider mini bike was a brake lever, cut off 2/3 handle, cut slot in remaining piece, and soldered a large washer. Put finger through washer, and that was my throttle. I looked last night for the 20 inch Sportster sheave for the whizzer, that was sold out in the only place I could find one. 20" inch bike rim, likely narrowest available and how would it connect to a 26 inch rim? Thanks for welcoming me here.
     
  4. curtisfox

    curtisfox Active Member

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    20" bike rim is the same size as Whizzer pulley they measure just under 16" ......Curt
     
  5. curtisfox

    curtisfox Active Member

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    If you study some old motorcycles they use a Z shaped brackets, most have 9. But then you have to bump the frame out were the rim goes to make room. Yep my first bike was built with paper route money, and go-kart, but was the only one that had one back then 5 years older than you. First seen one in little pages of R&C, so built it out of bed rail and pipe. LOL
    https://www.google.com/search?q=190...ei=Z_tMV-PWComwyAK9uoNY#imgrc=-GpibEtOHzzPdM:
     
  6. ragdolldude

    ragdolldude Member

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    I've seen a close up of those "z clamps" before. Is there a tutorial, something on YouTube, or a link that you know of that explains the easiest way to make these clamps. Attachment: brazed, bolted, pop rivets, or how were these counted?? Thanks
     
  7. MEASURE TWICE

    MEASURE TWICE Active Member

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    Welcome!

    http://www.diygokarts.com/vb/showthread.php?t=9097

    I found this is searching what I guess is what you have... a torque converter.

    GX50 I looked up and is 4 stroke which is better for low end power, but says 2hp.

    Some people have said that most torque converters are needing at least a 5hp engine to run them.

    I have a 26 inch rear wheel sheave that is a cloned Chinese Whizzer type of 15 inch. My 3hp Briggs I use a jack-shaft reduction of 20:1 ratio with a centrifugal clutch. I don't have it go but 15 - 20 mph, but am exclusively using it for trail riding legal with CA OHV Reg I got. No pedals, just foot pegs.

    At one time I had a smaller sheave, actually a washing machine pulley maybe 10 inches diameter and put a dual jacks-haft to get that 20:1 ratio. I don't need that extra jack-shaft any longer with the larger diameter sheave, so not to bother undoing the work, I just run a short chain connecting 2 sprockets of the same diameter.

    When the washing machine pulley was worn, I would have like to find one in stamped steel like I had back in the 70's, but no luck now, everything pot metal. Some of the cloned stuff I expect is not the best. The Whizzer company, or the one company having rights to the name selling the better stuff had none in stock when I looked. Other sellers had something that were either Whizzer or in any case good reproduction of Whizzer, but I found the cost more than I wanted to pay. About 50 dollars I got a cloned version on Ebay.

    I sanded the rough weld bump in the clone sheave and used my own fasteners and am satisfied with it, except under a lot of torque up hill and it can slip. Also a splash of water riding trough a stream with big enough splash and it takes a little while to dry before it grabs well again.

    The torque converters that I see some of have wide belts, so they may not slip. The rear wheel with the sheave though is a weak spot using A section 4L belt. Maybe find a synchronous toothed belt and a synchronous pulley and attach to rear wheel some how. I expect dollars for synchronous stuff though.

    RDD, maybe some of this may apply to your usage of the bike you build or not. Use what info you can to decide how you build based on that.

    http://motorbicycling.com/showthread.php?t=54926 Trail riding

    http://motorbicycling.com/showthread.php?t=29678 The beginning
     
    #7 MEASURE TWICE, May 31, 2016
    Last edited: May 31, 2016
  8. curtisfox

    curtisfox Active Member

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    I used stainless button head bolts, and my Z straps are cut from tapered hinges. Had a ring 1/8" x 3/4"rolled at the local steel supply, ( if i were to do another i would use 16 gage ) then cut and fit to inside of my 24" rim. Welded the Z straps to it. But could be riveted, then i turned the head down on button head bolts to bolt the 24" rim to it. ............Curt
     
  9. ragdolldude

    ragdolldude Member

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    I'd only seen the V-plex clutch on an engine--had no idea they even made a torque converter. My old low rider mini bike was a 2-3 hp 2 stroke Power Products, rescued off a lawn mower that had been turned into a local metal recycler. That old clutch and the new clutch being shipped to me are both for 5/8" engine shaft. I did run across an online copy of a 2007 motorcycle magazine that had a reprint of an article from a much older Popular Mechanics article, that seemed to show the process of attaching a 20" bike rim as a sheave to a 26 inch motor bike. The article was barely readable and was in a PDF format, so I could not print it. Online ordering of reprint of magazine was supposedly available, but link took me to a domain that was unavailable and offered for sale. Close but no cigar on that effort. I was just trying to find some more distinct details on making these z straps, instead of the time involved in "trial and error" to make these. Thanks everyone for making suggestions. It's taken me several years to find the NOS V-plex clutch, and I'd like to make it part of my bike, street legal in CA with 49cc.
     
  10. curtisfox

    curtisfox Active Member

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    Ya i am with you on the clutch, i bought mine new back when, and run it on my bike, worked awesome. There is another way you can get Briggs throttle clips,and clamp to the spokes just like the Whizzer. I think the law has changed in CA to 4hp now. But like your choice, and the little Honda revs up to 7,800.................Curt
     
  11. MEASURE TWICE

    MEASURE TWICE Active Member

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    I'm going to try a used better condition replacement engine I got which has a little extra power up from 3 to 3.5 hp Briggs. I needed to use a different setup as the crankshaft on the engine is not the same 5/8, now 3/4 and also is short shaft can't fit the clutch. I'm going to try using a sprocket of either 12 or 13 tooth on the 3/4 engine crankshaft. It will route to chain to an already existing jackshaft on the bike. I can have that live jack shaft either 1:1 ratio or 1.083:1 ratio as the clutch is 13 tooth.

    This means I have to instead have the clutch fully engage at engine speed above 2000 rpm if I use the smaller engine sprocket 12 tooth. So it would be 2166 rpm to lock the shoes, I wonder would it be useful that way? Maybe get up and go better if the engine and clutch work. Otherwise I'll just go 1:1 ratio in the first chain.

    Over all ratio will be available to switch from 19:1 ratio, 13:1 ratio and 10:1 ratio. I probably would rule out the 10:1 as a long time ago 8:1 is the way I started out, it never worked. 13:1 is a bit slow. 19:1 less torque but I have powered though viscous mud with run up speed.

    Here is the old clutch I have and it looks rusty, but is cleaning up and the shoes move OK. The back idler pulley was used with the other engine and belt clutch, but it can be switch back to the old engine with belt if I decided or something happens requiring it. Anyway I've not ran with the engine and tested yet the toothed clutch, it is a brand I can't find info on. It is a Top Man clutch an says manufactured in Rancho Cordova, CA. You ever known of this brand clutch?

    MT

    I don't have ground clearance for this :(

    http://motorbicycling.com/attachment.php?attachmentid=69633&d=1398150553
     

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    #11 MEASURE TWICE, Jul 29, 2016
    Last edited: Jul 29, 2016

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