How to climb big hills with original GEBE kit?

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MtnGoat

Guest
I posted the whole story in the introduction forum, here: http://www.motoredbikes.com/showthread.php?p=83757#post83757

This post by uncle punk13 really intrigues me as a solution: http://www.motoredbikes.com/showthread.php?p=55426#post55426
The gist is "For multi-speed gearing you could have a three speed hub laced onto your rear hoop, and mount the shifter on the handlebars."

I've thought about this, but can think of no practical way to do this.Any ideas on this or on other ways to get up the mountain with GEBE?
 


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OldPete

Guest
Cutting right to the chase...

Sell your current kit, might sell fast if left on the bike for "testing".
Buy the GEBE Tanaka 33cc kit with the 12 tooth drive gear, it normally comes with the 13. Return to 26" wheels. I geared my Robin/Subaru 33.5cc kitted bicycle to have a top gear of 46/11, seems to work for me but I have yet to pull long, big hills with my 60yo legs. If you are worried about spoke breakage, buy the $109 rear 26" wheel from GEBE that is laced up with 12g spokes.

bamabikeguy will prolly offer you something. He has ridden cross country and has encountered a hill or two.

David Staton is testing this hub but here in Ca. it moves the pedal assisted bicycle into mo-ped territory. It will pull all the way down to 6 mph.
http://www.staton-inc.com/Details.asp?ProductID=3216

Read more in the rack mount forum because every new member seems to want a full tutorial then never returns to "give back" anything except complaints because of thier own ineptitude. :cool: Or so it seems. Bwahaha!
 
M

MtnGoat

Guest
Perhaps the 33 Tanaka would do it, but I would want a strong "yes it does" from someone with experience climbing long severe grades before trying another version of the GEBE. I can't tell you how many times Dennis at GEBE told me that what I have should climb these 20% grades no problem. Every fix he suggested made no or only very minor improvements. Eventually I just threw in the towel.

I've looked into the NuVinci hub, but decided it was too expensive. Didn't know that would turn a bicycle into a moped in CA. Multi geared I suppose. But I would think that if the motor uses the existing gearing of the bicycle, that would make it gray enough to get by. And hard to spot as well.

That would be another reason to use the bicycle gears to get multiple gearing, like through an internal rear wheel 3 speed (or more) type hub.

One thing that bothers me about the the Staton gear box is that he states on his web page: "The Robin - Subaru, Honda, Mitsubishi & Tanaka engines last about 8,000 miles before the clutch shoes wear out with our gear & chain drive kits, then they will run another 2,000 to 5,000 miles more before the engine needs replaced." Maybe he's just being honest and it's the same for all kits, but 10,000 miles doesn't seem like that much, especially considering the long 2000 mile break in of these high performance 2 cycles. Made me wonder whether the gear box design is a contributing factor. I read somewhere in these forums that he is designing a lighter duty gear box specifically for bicycles.
 
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DougC

Guest
I do not understand how you could easily adapt any regular bicycle geared hub to "the GEBE drive ring", as bicycle hubs have their drive sprockets on the opposite sides that the GEBE ring fits on.

...And for that matter--the bicycle hub sprockets are on the opposite side that most motor-bicycle engine kits drive the rear wheel on. Not just GEBE.

The only way you could do this is if you modified the engine's drive setup to run on the RIGHT side of the bike--but then, it's been commented that a 1 HP engine will put out at least TWICE the power continuously that most casual riders can manage to put out for even 5 minutes. Bicycle hubs aren't engineered to be strong enough to be driven by a motor, 1 HP is about 750 watts and an average casual rider might be able to cruise with their legs putting out 150-200 watts.
~
 
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OldPete

Guest
You will have to contact Mr. Staton about his up n' coming smaller gear box(I posted what he told me via phone several months ago). His current box is bullet proof and his system will deal easily with the rip-roaring hp of a Tanaka 47R. One of his HD wheels MUST be used however.
Clutch life is dependent on break in and the amount of pedal power used for launch/hill pulling. Engine life is dependent on very clean air. The Tanakas and Robins should see 15k miles...or so I have read. Oil gets changed quite often in my Robin.

larymor,
Search and read my posts. I place helpful information way above being "friendly" to the many that are just passing through. You should do like wise. ;)
 
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OldPete

Guest
I do not understand how you could easily adapt any regular bicycle geared hub to "the GEBE drive ring", as bicycle hubs have their drive sprockets on the opposite sides that the GEBE ring fits on. ~
Please quote where anyone said the NuVinci hub could be adapted to the GEBE system.
 
M

MtnGoat

Guest
I do not understand how you could easily adapt any regular bicycle geared hub to "the GEBE drive ring", as bicycle hubs have their drive sprockets on the opposite sides that the GEBE ring fits on.
~
That's how it appears to me as well. I love the basic idea of using an internal bicycle hub though. Somehow...

The only way you could do this is if you modified the engine's drive setup to run on the RIGHT side of the bike--but then, it's been commented that a 1 HP engine will put out at least TWICE the power continuously that most casual riders can manage to put out for even 5 minutes. Bicycle hubs aren't engineered to be strong enough to be driven by a motor, 1 HP is about 750 watts and an average casual rider might be able to cruise with their legs putting out 150-200 watts.
~
I wonder how much torque Lance A. applies to the gearing when out of the saddle racing up Alps de Huez? Maybe the hubs are stronger than you think, if not abused. And if a competetive cyclist can climb a steep grade outputting say 400 watts, think what a 1 hp motor should be able to do with proper gearing.
 
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DougC

Guest
That's how it appears to me as well. I love the basic idea of using an internal bicycle hub though. Somehow...
Well maybe you could, but not on the rear wheels axle: such as use a big sprocket on the rear wheel, and use the internally-geared hub as a compound-drive, such as the "middle" pulley on a Whizzer setup. The hub wouldn't be subjected to nearly as much torque that way.
I wonder how much torque Lance A. applies to the gearing when out of the saddle racing up Alps de Huez? Maybe the hubs are stronger than you think, if not abused. And if a competetive cyclist can climb a steep grade outputting say 400 watts, think what a 1 hp motor should be able to do with proper gearing.
When I said a "geared" hub, what I meant was an internal-geared hub, like a 3- or 7-speed, which can withstand a lot less torque than the common external gear hubs that most US bicycles use. US bicycles use externally-geared hubs because it's cheaper, but one side-benefit is that they are easier to build stronger.
~
 
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BTB Wild

Guest
Hills

Well OLDPETE I ordered both the 11 tooth AND 12 tooth gear for my new Tanaka 33cc. I may hold off until I break in the engine though. I'm in decent shape and can tell you the std gear won't cut it around here. Many hills are steep. Hopefully, I have not damaged the clutch on my maiden voyage as I kept er full throttle up a hill until I came to a stand still. I quickly realized I had to be damaging the clutch. Will the clutch forgive me for this single episode?
Winter will set in fast so I may not realize a full break-in till spring time. :cry: Dying to try the new gears however.
 
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