how poorly would a stock 142F perform with a Comet knockoff TAV ?

freddi

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Apr 17, 2019
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my state has a 49cc legal limit and nearby roads probably ~20% grade in some places - plus I'm heavy. Assuming a TAV would mount (?) and proper overall gearing, could the little engine's power band make the TAV cover its entire ratio range? - Would the clutch engage too early? Is it a lost cause? I'm old with long time vertigo and other issues so can't get a driver's license.
 


The_Aleman

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You'd pretty much end up with a very wide belt-eating slug. Those small CVTs incur significant power loss and the 142F doesn't have enough torque to perform well with it. A single-speed setup geared between 18:1 to 20:1 with a decent clutch will do a much better job.
 

freddi

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Thanks ! ~ 1.47 Ft. Lb. doesn't go very far - especially with losses. I have a Chinese TAV backplate - must be ~12mm thick in the clutch area - is there enough shaft on the straight shaft 142F to poke through and mount a centrifugal 10T 5/8" bore clutch ? Another option might be to use a TAV w. 79CC and hope its size not noticed. Looking at proper setups, I think there may be some bad alignment problems using a cast aluminum TAV backplate as a jackshaft carrier as its power output sprocket is on the "left" side (viewed from the rear) of the plate and could shove the engine further to the right - if the protruding bearing carrier doesn't hit the seat post tube.
 
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The_Aleman

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The high-revving nature of the 142/144F doesn't lend itself well to the CVTs or the kart clutches when mounted directly on the PTO. What's been done is under-driven kart clutches, which works pretty well for a straightline cruiser, not so great for hills unless geared quite low.

If your heart is set on that TAV, I'd get the HF79. It's about 8lbs more than a HS49 and is a torquey chugger out of the box. There's some aftermarket for those engines, there's practically nothing serious for high-rev clones. If you're a big dude and have hills, you're gonna need the torque!
 

freddi

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@The Aleman - advice much appreciated. At age 69 I don't expect to be around forever. Three of my toys have TAV2 with the steel mounting plate: Cushman Silver Eagle (8HP IIRC) and a minibike with 10 or 11 HP (I didn't build either) interestingly, neither TAV seemed to slip despite the big motors and the minibike was serup very crazy - hydraulic rear brake but only #35 chain plus for some reason there's slop in the second jackshaft's bearing carriers (holes enlarged ?) that shaft wobbles - don't know what would fix that other than new carriers and those are welded to the frame and rear fender. All my stuff is rusting as sets out in a Shelter Logic tent where my cats track mud to every square inch of tubing, whatever and claw the seats. I looked for a picture of my red minibike but to no avail. There used to be one at Oldminibike's forum. That 35 chain stretches quick under the torque. I've got 3 Acme minibike frames needing painting - loading. I'm not a good mechanic.

Out of the common cheap bicycles at Walmart - are they any you would recommend as being better overall and having better wheels / spokes than av average ?
 
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JerboaJohn

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box store bikes have the cheapest wheel hub spoke setups possible. my no-torque 48cc 2 stroke ate up the stock rear hub within 2 months. single speed cruisers are slightly heavier and should last 5 or 6 months but no guarantees!
 

The_Aleman

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@The Aleman - advice much appreciated. At age 69 I don't expect to be around forever.
You've got 26 years on me sir, but I'm old enough to know that in the grand scheme of things, human ego is futile.
I may be enthusiastically vocal in my sarcastic cynicism in some places, but if life is a highway, I'm happy doing 25.

Three of my toys have TAV2 with the steel mounting plate: Cushman Silver Eagle (8HP IIRC) and a minibike with 10 or 11 HP (I didn't build either) interestingly, neither TAV seemed to slip despite the big motors and the minibike was serup very crazy - hydraulic rear brake but only #35 chain plus for some reason there's slop in the second jackshaft's bearing carriers (holes enlarged ?) that shaft wobbles - don't know what would fix that other than new carriers and those are welded to the frame and rear fender. All my stuff is rusting as sets out in a Shelter Logic tent where my cats track mud to every square inch of tubing, whatever and claw the seats. I looked for a picture of my red minibike but to no avail. There used to be one at Oldminibike's forum. That 35 chain stretches quick under the torque. I've got 3 Acme minibike frames needing painting - loading. I'm not a good mechanic.
Not to presume, but really, you're old enough that you can take a look at things and perceive how they work. Mechanical chain drivetrains go back to our interested ancestors a century ago or so ago. Honestly and humbly, being mechanically inclined is is a mindset. If one is interested in how things work, it's never too late to research and learn how things do. Heck, there's YouTube videos for almost everything these days!

Out of the common cheap bicycles at Walmart - are they any you would recommend as being better overall and having better wheels / spokes than av average ?
Well, I'm not up to date on that. I have never bought a Walmart bicycle, even for pedaling, although I have been tempted. I have a story.

The last cheap new bike I bought was at Target, it was fall of 1997. I had just got off the plane from Anchorage flying back home 1-way to San Jose airport with 3 suitcases, and it was the pager days and I couldn't get ahold of any of my people when I had come back unannounced. So, I had an enthusiastic Indian taxi driver take me from the airport to a Target near my old Cambrian Park neighborhood of San Jose.

I paid the taxi driver to idle outside Target and watch my luggage while I went inside the Target, bought a crescent wrench, a metric allen wrench/screwdriver set, a 7-speed Huffy cruiser (maybe the great-grandfather of the Cranbrook), and a bottle of Slime. It all cost me $117. I grabbed my 3 suitcases, paid the taxi driver off, and fixed/Slime'd that bike right there. A tire shop nearby supplied the air. Flipped the handlebars, threw all my bags on my shoulders and rode 3 miles home like a boss. Good times. Anyway, I sold that bike to a small Mexican after rebuilding the bottom bracket twice because of knocking.
 

Spare_Parts

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I hate the bottom bracket knock! Used to take the balls out of the cages and just run them loose back in the 80s lol. Think it took like 5 sets of caged bearings to do 1 bottom bracket.
 
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