need help...Tanaka 47R

peddler

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Jun 16, 2008
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Looking for a clutch cup assy with shaft. I'm new and just starting a build. Do the china bike gearcases have a 78mm clutch cup? I have one available to me. I don't really want to buy a whole kit and I think this motor will rip a GEBE setup to shreds! Any suggestions?
 
Staton-inc used to sell kits with the 47r. I would rifle off an email to them to see if they have a gearbox setup that will fit it still. I wish they still made them I've heard they are mighty powerful.
 
Gebe needs to make a high torque version of their setup using one of those thick timing belts and a mag wheel with the spoke ring affixed and pre-centered. If I were them I'd be all over that r+d. Using automotive belts would give the benefit of being able to go into an auto store and ask for a timing belt rather than ordering one. I recently helped my paps replace his timing belt on his nissan frontier, **** thing lasted 130k miles before it finally de-laminated itself. Of course efficiency would drop with the larger belt but if you could use larger engines with the gebe kit it would totally haul being so lightweight.
 
Gebe needs to make a high torque version of their setup using one of those thick timing belts and a mag wheel with the spoke ring affixed and pre-centered. If I were them I'd be all over that r+d. Using automotive belts would give the benefit of being able to go into an auto store and ask for a timing belt rather than ordering one. I recently helped my paps replace his timing belt on his nissan frontier, **** thing lasted 130k miles before it finally de-laminated itself. Of course efficiency would drop with the larger belt but if you could use larger engines with the gebe kit it would totally haul being so lightweight.

Good idea SirJakesus. One thought about that though is why would they want to de-prioritize their belt? I would think the profit margin on those belts must be pretty high. I think the mag wheel is an AWESOME suggestion...that seems (to me) to be the weakest link in many of these kits.

Warner
 
I agree, GEBE would do well to r&d a wider belt for the larger Tanakas; granted it would be a lot more expensive but some folks would be all over it, I'm sure!
 
The belt GEBE uses might work better if the drive sprocket was larger in diameter (more teeth to distribute the load to) but that would alter the gearing. A wider belt would not track as easily and a thicker belt wouldn't bend around as tight a radius. IMHO, a small primary gear reduction box bolted to the clutch PTO would be a plus and then you could go to a heavier belt with larger drive sprocket. I'd guess that there is a good amount of engine bracket flexing during normal use and a high HP setup will compount this problem. Bracket flexing will loosen the belt and cause it to twist and not track as intended. I've used this type of toothed belt on industrial drill motor setups with no problems for millions of cycles, but again, these machines are very ridgit in design.
I'm kinda surprised a primary chain setup would hold up any better than a belt system. Roller chains don't take well to open air high speed use. They require lots of lubrication and that would be impossible on a bicycle.
 
I'm kinda surprised a primary chain setup would hold up any better than a belt system. Roller chains don't take well to open air high speed use. They require lots of lubrication and that would be impossible on a bicycle.

I'm not sure I understand your logic regarding chains. Motorcycle and bicycle chains both seem to hold up for great lengths of time, and although they need PROPER lubrication, I don't think that equates to "lots" or "frequent" lubrication. Just my thoughts. I don't think it's the belt that is the weak link in the GEBE system though....I still think it's the wacky looking ring that attaches to your spokes, as opposed to a normal sprocket and hub like the Staton kit uses. Just my opinion, of course.

Warner
 
yup, only opinion, all about the fun...here's mine

well, let's look at this geometrically. again, i don't need to bump sales, this is about the fun of "bench-racing"...

i don't care where you drive the wheel from...ultimately, it comes down to stressing each individual spoke at a single point, right? well, think about it...properly installed, the gebe drivering actually exerts the (motorized) stress at a point that is more "wheel-friendly" than any hub-based drive can possibly be...by moving the point of stress closer to the rim, you've reduced the overall stress to the whole wheel assembly. the drivering fits the spoke arrangement very precisely, and serves to hold the spokes in their proper position better than a hub or sprocket can. it's mechanical logic.

and, because we're talking about weight and power ranges that are significantly smaller than any other vehicle, belt-drive makes sense. imo, any wheel that the gebe system would break wouldn't stand a chance being hub-driven.
 
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Okay...first let me state that I think the GEBE and Staton systems are the two best that I have found. I'd be happy with either of them. I've stated before that the show-stopper for ME was that the GEBE system doesn't truly freewheel and the Staton system does. That was imperative to me, personally. Many people won't pedal as much as I intend to though and that won't be a factor at all. Beyond that, here are my thoughts in regards to your comments:

i don't care where you drive the wheel from...ultimately, it comes down to stressing each individual spoke at a single point, right? well, think about it...properly installed, the gebe drivering actually exerts the (motorized) stress at a point that is more "wheel-friendly" than any hub-based drive can possibly be...by moving the point of stress closer to the rim, you've reduced the overall stress to the whole wheel assembly. the drivering fits the spoke arrangement very precisely, and serves to hold the spokes in their proper position better than a hub or sprocket can. it's mechanical logic.

I disagree. I'm not an engineer, but if I'm not mistaken, the GEBE drive ring does not use ALL of the spokes to drive the wheel, correct? And the Staton system (just like a bicycle or motorcycle) shares the load between ALL of the spokes, by virtue of driving the hub itself which all of the spokes attach to. Unless someone can prove to me scientifically that it's not true, I refuse to belive that the GEBE system is more robust or puts LESS stress on the wheel and/or spokes than the Staton system.

and, because we're talking about weight and power ranges that are significantly smaller than any other vehicle, belt-drive makes sense. imo, any wheel that the gebe system would break wouldn't stand a chance being hub-driven

I don't doubt the strength of the belt itself at all. Harley Davidson uses a belt drive system on many of the big torque v-twins and it's quieter, smoother, lighter, and more efficient (only by about 1% max) than a chain drive system. In fact, you'd probably see this on more motorcycles if Harley didn't own most of the relevant patents on the system. I'm not against the belt drive aspect of the system at all. I just don't like the drive ring attaching to the spokes. I don't believe that it's stronger than the Staton system. An easy test would be for someone to simply pedal two identical bikes with identical rim setups as far as the gauge of the spokes and same wheels, etc...one with the Staton hub and one with the GEBE ring (but you'd have to hook the pedal sprocket up to the GEBE ring on the spokes somehow). While pedaling, shock each one by jumping on the pedals over and over and see which one failed first. You can do this on a nomal bicycle (with the hub driven setup) all day long with no ill-effects. Can you do this with the GEBE ring attached to the spokes? Not on one that *I* paid for, thanks. Again, maybe I'm way off base on this, but those are my thoughts about the comparison between the two systems. I have ZERO vested interest in either kit....these are just my opinions.


Warner
 
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