Rag joint or hub adapter the only options?

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lewdog7431

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Feb 13, 2019
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check it out guys I got the hub adapter but I drilled a hole taped it and put a bolt in there to tighten to pretty much any sprocket and the spacer in between the spokes for the gap it works well
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Tony01

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indian22

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This is the easiest solution. Sprockets from 40 to 60t, brake, freewheel, 17” tires can be found just about everywhere from moped tires to small motorcycle tires. All setup for a 12mm axle. And it’s a rear wheel you can grow with. No sudden problems when you move up to a bigger motor with a rag joint.

https://www.treatland.tv/17-black-bernardi-five-star-REAR-mag-wheel-p/bernardi-blk-rear-5star.htm
Tony that's truth & the Treatland wheel is dang sure priced to sell. You'd be right to think there's a "but" coming and there is. Those just coming into this hobby don't yet have a clue and many who've been building for years using sprocket clamping adapters and CG engines are doing fine on non DOT compliant tires and wheels at 25 mph cruising speed. Some can't or won't spend money to convert bikes that are ridden at pedal bike speeds, nothing wrong with that. Others have bike frames & forks that won't allow the wider profile tires to fit. Not a problem for advanced builders but for the novice it's a daunting task when they struggle just to break down a tire or fit a chain.

For those that really want to cruise fast with more powerful engines, going the moped route makes complete and irrefutable logic and the 17" wheels and tires are readily available

Rick C.
 

waynesdata

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What is the needed size difference between the hub-adapter and hub? I would test .0015 to .0030 and see what happened. Maybe a key way between hub and adapter would be best for most people.

With the long running post about who has a cnc machinist shop someone has to know?
 

indian22

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Sizing Wayne is specific to hub and adapter. The answer to your question is it varies. Each hub and each adapter will vary...perhaps as much (more or less) as you've speculated and the non-machinist is stuck with what's offered which will vary application by application. I owned machine shops for more than thirty years and I've built more than a dozen motorized bikes & all of these eventually used 1.5" adapters, built by various manufacturers. I used these on various quality 1.5" cruiser hubs, and cruiser hubs are what they were designed to be used on. I've had exactly one slip that caused slight damage to a couple of spokes and that was an extremely cheap adapter which had a very narrow clamping surface and overall poor design and machining quality on an inexpensive cruiser hub. I didn't attempt to re-use this adapter as a sprocket holder, though I did eventually use it in a much modified form to secure a rear disc rotor on another build.

My observation is to buy quality components from trusted vendors and then tighten the crap out of these things, don't use hex keys , use a 1/4" drive ratchet (minimum) to tighten the clamp fasteners and properly apply blue, medium strength, thread locker to the threads before assembly.

These three things: use the proper size cruiser hubs matched to the correct adapter size, buy quality from a trusted source and then install properly have worked for me over the last ten years and never once have I suffered angst over a few ten thousandths variance over a part that was by necessity intended to be used interchangeably on a variety of cruiser style hubs. I do however take full responsibility for making a poor decision to save $30.on a "bargain" adapter. That's on me.

Rick C.
 
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lewdog7431

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I may not be as old as you guys and all fuckin wise but I built my bike from scratch with what's offered and I make it reliable ,I have my own business and I use this motorized bicycle for transportation ,hauling,and all kinds of **** not ment for bicycles,i wouldn't post **** if I didn't know **** ,can care less if you approve of the hub adapter or not just trying to participate and share ideas with you stuck up assholes
 
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indian22

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Lewdog somewhere in my posting I showed photo of the sprocket hub adapter that I used as a disk brake caliper adapter. I used this modified adapter backed up to and cross bolted to another sprocket adapter on the same hub. These two bolted together increased the clamping surface area by almost 75% ( one was much narrower than the other) & in effect did what your modification to the adapter is doing to prevent potential adapter slippage. I thought it a solution to possible adapter slip using bicycle hubs coupled to much more powerful motors and still do.

Since I mostly build vintage style bikes that have the early twentieth century look. I've used mostly bicycle "clincher" wheels and tires to capture the look of what was used in those early days, not because they are better...they are not, but with quality tires & tubes I've found they handle sustained 30 to 35 mph cruising speeds well. Relatively stock kit motors using 36 tooth sprockets can typically do this on flat roads without too much engine strain and in some states 30 is still legal if I'm not behind on legislation rules and regs.

No one should ever have to feel the need to justify what, how or why they build things as they do; and no one has the right to order or vilify anyone into any position that requires such defense. Advice & opinion (correct or incorrect) is just that and each one of us has the right to accept it or reject it in part or as a whole. That said all critique should be offered with due respect. This is my humble opinion.

"Participate and share" are words of wisdom regardless of ones youth or maturity. This tends to build strong forum & societal community; all the while building, riding, enjoying and having fun!



Rick C.
 

PsychDoc

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Sep 8, 2019
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Indeed Rick- you speak works of great wisdom. The moped wheel is one to look into, someday.

For what is worth- I have purchased and will be using a 24” steel wheel with 12g spokes and coaster brake hub.

Another question - has anyone seen an adapter to go from the ubiquitous clam shell to motorcycle sprocket?
 
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indian22

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Just to clarify. Are you referencing the three bolt sprocket to hub adapter, as the clam shell? If so the extensive listing of quality 1/2" pitch sprockets & chain available to bolt right up to them is hard to beat and in my opinion also qualify as light motorcycle sprockets. I'd think these sprockets could handle upwards of 30 hp easily. Far more than the bicycle hub could withstand or the adapter to securely hold in place.

To answer your question that would be no I haven't, but there possibly could be I suppose.

Rick C.
 

PsychDoc

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Yes Rick, that’s the adapter I refer to. Trying to think of alternatives, a lot of the motorcycle sprockets look good and are inexpensive. I will stick with the standard setup.

I found a 56 tooth but nothing larger yet- the search continues
 
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indian22

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Have you decided if your going to power this bike with a China girl 66 cc or a small 4 cycle motor? This will make a real difference in the sprocket you select as will going with a CVT on a 4 stroke. Your weight and terrain also enter in to the sprocket decision. Rule of thumb with 4 cycles was 48 or larger and with 2 cycles 44 tooth or a bit smaller...seldom have I seen the need for more than 48 tooth on a 2 cycle CG. The use of CVT's on 4 strokes has changed the rule of thumb for 4 strokes depending on the CVT pulley ratios you can utilize smaller sprockets final drive.

Just something to confuse you with I'm afraid.

Rick C.
 
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PsychDoc

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Have you decided if your going to power this bike with a China girl 66 cc or a small 4 cycle motor? This will make a real difference in the sprocket you select as will going with a CVT on a 4 stroke. Your weight and terrain also enter in to the sprocket decision. Rule of thumb with 4 cycles was 48 or larger and with 2 cycles 44 tooth or a bit smaller...seldom have I seen the need for more than 48 tooth on a 2 cycle CG. The use of CVT's on 4 strokes has changed the rule of thumb for 4 strokes depending on the CVT pulley ratios you can utilize smaller sprockets final drive.

Just something to confuse you with I'm afraid.

Rick C.
Not confused at all- thank you. I will be using a handy CG160. I actually bought 3 of them - $50 each. I’m debating how to mount it now. Thought about welding (I need to learn to weld) in a mount, but if I find something bolt on I might do that.

Your thoughts on trans and sprocket?
 

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indian22

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Well I'd probably go with the 3 D manual clutch using a bottom bracket style reduction sprockets & wide pedals. The GC 160 make about 5.5 hp at 3,800. So I'd try 12tooth motor output to 24tooth reduction input to 10 tooth output and depending on what cruising speed I want....select a rear sprocket I'll calculate whatthat looks like with a 26" rear wheel and get back to you in a bit .

That's theoretically 45 mph with a 38 tooth rear at 4,000 rpm, just as an example that will give you an idea of what to expect. I'd not spin the GC faster than that with out some valve train works especially stiffer springs. If you disconnect the governor you have to go easy on reving this thing. Single speed.

Moto Mags did a GC 160 with a CVT and he likes it as many have using various engines.

High end cent. clutch like the Bully is also a proven way to build a drive train and using the reduction drive I described above, but with different drive ratios. Jack shaft can be used in place of the bottom bracket reduction drive as well on the 3D and the Bully clutch ...Sportsman offers a specially modified version of the Bully for use on moto bicycles rather than go carts that are setup way different for small diameter tires.

None of these are inexpensive setups & all have proven they work. These are three of my favorites, but there are others like the final belt drive with no clutch that are frequently built classics.

Pick your favorite and deal with it, all use 3/4" outputs.

Rick C.
 
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waynesdata

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Well I'd probably go with the 3 D manual clutch using a bottom bracket style reduction sprockets & wide pedals. The GC 160 make about 5.5 hp at 3,800. So I'd try 12tooth motor output to 24tooth reduction input to 10 tooth output and depending on what cruising speed I want....select a rear sprocket I'll calculate whatthat looks like with a 26" rear wheel and get back to you in a bit .

That's theoretically 45 mph with a 38 tooth rear at 4,000 rpm, just as an example that will give you an idea of what to expect. I'd not spin the GC faster than that with out some valve train works especially stiffer springs. If you disconnect the governor you have to go easy on reving this thing. Single speed.

Moto Mags did a GC 160 with a CVT and he likes it as many have using various engines.

High end cent. clutch like the Bully is also a proven way to build a drive train and using the reduction drive I described above, but with different drive ratios. Jack shaft can be used in place of the bottom bracket reduction drive as well on the 3D and the Bully clutch ...Sportsman offers a specially modified version of the Bully for use on moto bicycles rather than go carts that are setup way different for small diameter tires.

None of these are inexpensive setups & all have proven they work. These are three of my favorites, but there are others like the final belt drive with no clutch that are frequently built classics.

Pick your favorite and deal with it, all use 3/4" outputs.

Rick C.
That got me to looking at Honda engines. Maybe the Honda GX100 "100cc" could be a drop in replacement for 79cc predator? Just looking at the picture it has the advantage of looking very much like the GXV50 "50cc" Would have to research transmission options. Being a Honda it could be better built.
 
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indian22

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Will do.

The 2stroke supercharger on a 2hp CG won't work well, requires too much power to get it pumping. However the new electric driven superchargers powered by lithium batteries would pump instantly on demand. It would be costly. Zeda has a video of a CG, highly modified, billet block CG (80 cc ?) on their dyno that puts out almost 17 hp @ 9,000 rpm also quite expensive. I'd think that would power a purpose built bike 90 plus with a small fairing.

Rick C.