use "happytime"gearbox 4 pocketbike engine



Originally, the idea to mate a pocketbike engine via p.b. sprocket and chain TO a used "happytime"(sans upper cyl, rod and crank).............using JUST the gearbox portion of the engine casing was my idea. This would allow usage of a 26" bicycle wheel ...........the usage of various pocketbike sprockets to fine-tune the gearing...............and still use a mountainbike frame.:cool: I admit to procrastenating ..........about putting this post up.......but the bike I wanted to try this on......I was peddling to work with until I get my blue oni 's (other 70cc mtb) "franken engine" back together again. (new bushings dont fit) Anyway............the drive sprocket on the pocketbike (p.b.) drives the p.b. sprocket ( probably 80t to 98t)..........the sprocket would need an adapter of some sort to mount it to. On my p.b. spoiler project.....................I used a lawnmower pulley and CUT a smaller pulley out of it with a dremmel .......and bolted it to the rim. Using this same adapter can be bolted to the happytime block.......where the magneto magnet once resided. A heavy duty bolt.........would then be used to mate the small bevel gear on the the p.b. sprocket. I've been thinking about this scenario alot.............since most other engines need either: a 20" wheel, a rack/mount ring drive , or jackshafts requiring welding. I rather come at a problem .........with LOW BUCK/ HIGH CONCEPTS.:)
:cool:Excuse me, Brian,

I'm having difficulty envisioning your project, as I suppose others find it hard to see my projects.

Where in the midframe is your pb engine mounted? Which direction are your crankshafts facing?

Where is your happy time gearbox located? How are the engine and gearbox connected?

Where and how is your driven sprocket mounted? Is it on the left-side rear wheel?

What is your gear ratio as it leaves the happy time box?

What is your final drive ratio, using 80t or 98t sprocket?

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:cool:Please excuse me for asking so many questions.

I have more.

Am I correct in presuming that the happytime box will be using its same motor mounts to bolt into the midframe?

There are 4 sprockets involved in this engine/drivetrain. When writing, can you specifically refer to them as p.b. drive sprocket, happytime drive sprocket, happy time driven sprocket and p.b. driven sprocket?

It would be easier to follow your train of thought.

"A heavy duty bolt...would then be used to mate the small bevel gear on the the p.b. sprocket."

*What small bevel gear? Are you referring to the 10t happytime driven sprocket? How would the bolt fit into the happytime interconnection? *

*Or are you using the heavy duty bolt on the adaptor on the happytime engine crankshaft?*

I cannot envision how the happytime box interconnects with the p.b. drive sprocket and the p.b. driven sprocket.

What are your HIGH CONCEPTS?

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Myron, if you went to zomby builders post of tranny would find I casually offered the fundamental epithany of a pocketbike china-fire (or "happy-time") union as an economical , familiar,alternative to all the various bicycle: converters, gearboxes, and transmissions that confound people (such as myself) who are NOT familiar with this nomenclature and their EXACT application there of. Advice was also given for me to start a thread on the subject.....but I thought word of mouth would suffice. Which it a fashion. I had suggested quite a few grandiose ideas with possible, realistic results on another site. Maybe it was a coincedence ......or matter of happenstance......but the SAME ideas I posted on that other site have shown up here As well.:confused: Forgive my bluntness....but, the IDEA of combining a pocketbike engine to a happy-time gearbox ...has been ghost-written in my opinion.:censored:
:cool:Brian, here's the way I see it.

On November 14, you mentioned the IDEA of using a happytime engine as a transmission. Others, including myself, responded favorably to your idea. Someone else MUST have thought about this same concept before, amongst the millions of motored bicyclists(including the 5 billion living Chinamen), past and present.

Unsure if anyone on this website THOUGHT about this idea before you. As far as I know, you're the first that I've noticed to mention the idea.

HOWEVER...and this is the kicker, Brian. I POSTED a new thread in PARTS & ACCESSORIES section TWO DAYS! BEFORE you or anyone else mentioned the possibility of happytime gearbox. My post stated that I was looking for a reverse-direction gear-reduction box for my pocket bike engine. It's all in my thread. I was on the lookout for a gearbox before your idea hit this forum.

I liked the idea of the happytime gearbox. I embraced the concept. You had your chance of starting a thread. When you did not, for your reasons mentioned, I simply incorporated it into my EXISTING thread.

Like I said in my thread, I deferred to Brian. I will not make any more entries until your box is running. If anyone asks me for input, I will refer them to you. You can explain the ins and outs of converting happytime boxes, ratios, sprockets, rpm/mph calculations, applications, calculations, measurements, costs, concepts, etc.

Be advised that you and I are NOT the only ones experimenting with this gearbox.:eek:

I may not be writing or posting anymore about my "RODGER Box", but I sure am working full-bore on developing this project. My happy time core arrived tonight. So far, I....:rolleyes:

I strive not for glory nor acclaim from my peers. I labor for the love of tinkering and creating, for my personal satisfaction of my achievements.

I would gladly share my ideas, concepts, failures and successes on my "RODGER Box" with any forum member.

Alas, my friends, I can no longer do so. I defer all glory to Brian.

All eyes are on you, Brian. You now have the all glory, attention, RESPONSIBILITY and expectation of developing YOUR idea into a reality.:cool:

By the way, Brian, I only subscribe to
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hmmmm I built this over a yr ago with pocket bike engine, I have another of these cags 49ccn and a a couple busted 70cc happys and it never crossed mty mind to join em . And I'm pretty sure i have the reduction gearbox.. i/''check if its reversed . cant remember


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myron, the following is my shade tree interpretation to using an engine I WANT to use......on a bike with the desired wheel size (26"), using a gearbox that is easy to understand as well as identify ("happy-time" or "china-fire": On a mtb frame.....a 47cc pocketbike engine would be mounted to the underside of the uppermost TOP of the frame. Think....underneath gas tank. Due to close proximity of engine.....heat sheilding such as aluminum sheet SHOULD be used. Although, JEGS and SUMMIT racing have even more flexible material you can use. Dynamat I think. From this point on ,I will substitute the acrynom: "p.b.e" for pocketbike engine. The "crank" or actually, the CLUTCH of the p.b.e. would face to your right. since someone seemed to mention that the p.b.e. would turn the sprocket at the wheel in the wrong direction. Since this idea is strictly in theory, and I dont have a workable model...YET....I would suggest this course of action. Only fore see able hurdle would be pull starting with your left hand.:rolleyes: From now on...the phrase...." happy-time gearbox" will be substituted with "h.t.g." The h.t.g. would be positioned directly BELOW the p.b.e. in the SAME position it would normally be in ....due to the simple fact you ONLY want the h.t.g. so that it may use the power of the p.b.e. to DRIVE the 415 chain or, the 081 chain(the 081 is best . It is the ligher,and smaller of the two) which usually drives one of the three choices of sprockets: 36t, 44t, or 50t. The 44t has the best over-all characteristics of the three as well. Very well balanced.As stated in an earlier post....this is a CONCEPTUAL IDEA......I have no working model as of yet. But...theorectically ...... the p.b.e. has a clutch housing, on that housing is usually a tiny 6t drive gear. The 6t drive gear would use a 25h chain that would connect and turn the pocketbike FINAL-DRIVE sprocket (a 98t would be roughly proxy the rpms of the removed engine piston,rod and crank circles) the final-drive sprocket would then need an adapter of some sort (perhaps a small pulley with bolt holes drilled into it for attachment to the final drive sprocket.) A slightly longer, harden bolt that would THREAD into the small bevel gear (the little gear that would turn WITH the crank that is on the right side of the h.t.g. that turns the Larger clutch gear that finally turns the 10t drive gear that is on the LEFT side of the h.t.g.) or, if necessary.....take the small bevel gear OFF and have a bolt or rod or whatever seems right in your own judgement to use.....and have it welded to it. This bolt or rod or whatever...would then bolt up OR be welded as the adapter that is bolted to the pocketbike final-drive sprocket (98t). What you WANT to do is use the h.t.g. OUTER engine oil- seals and related holes(2) as an "axle - carrier" for the bevel gear to /rod or bolt/ to adapter/ to pocketbike final drive sprocket combo. I t is very difficult to give exact directions WHERE and HOW MUCH OF.... the h.t.g. would be cut with a dremmel to allow creative working room. Such as if someone wanted to install better high-speed bearings. WHEW! Truely, a picture IS worth a thousand words.:rolleyes:Give me some time to finish rebuilding this .............." franken-engine " I can complete the dual carb project I can take pictures of that........ so I can start THIS project and put any naysayers to rest. Unfortunately, myron ........math ISNT my forte. inventive concepts and auto design are. I like to "shed light"on problematic scenarios and offer a BETTER solution thru fundamental, I cannot at this particular time produce any gear ratio formulas or data. Remember, this idea is based mainly on THEORY. Hope this unabridged thesis you requested is beneficial to your musings. Again, its ALOT easier to just DRAW some schematics and post that. Dont have a fax or own a digital camera......I use a disposible digital camera that offers a cd that allows posting of pictures. It allows 25 pics ........then you turn it in and wait a few hours to get the picture cd and photos. WILL be posting VERY SOON. By the way........where are your picstures 5-7??????????? :confused:
:cool:Hmmm, very interesting and unique, Brian. I honestly would not have thought about doing it that way.

As many members here have egged me on about, I have not mastered the art of posting pictures. I will ask my nephew to teach me how...soon.

I owe you all about a hundred pictures.

Myron,although the above post is some what belated.... I accept your challenge. Although the "glory" isnt what I'm after......or the "spot-light".........or the "confering"......just trying to create something different that no one else has done before. Just trying to establish a niche, and got too competitive while doing so. For this .....I apologize to you, 5-7 and any members of motored that I may have offended. It is true that in any ardent hobby many minds WILL have the same notion. Again........ my bad.