G4 transmission

vooodooou · #1 (**permalink**) 08-21-2009, 10:44 PM

i was doing a Google search and found this.

4 STROKE 49CC 4GT BELT DRIVE MOTORISED BICYCLE KIT - eBay, Other Cars, Bikes, Boats, Cars, Bikes, Boats. (end time 18-Sep-09 17:23:07 AEST)

broHSI · #2 (**permalink**) 08-22-2009, 12:41 AM

Do you want to buy one?
There are 50 Grubee G 4 kits in Australia and there are also 50 kits in the US

vooodooou · #3 (**permalink**) 08-22-2009, 11:15 AM

i have the right motor and clutch just need the transmission.

Zev0 · #4 (**permalink**) 08-22-2009, 11:38 AM

The belt and gear look very similar to the GEBE system. I know that in AU you can get a knockoff of the GEBE system too. I believe that I've heard reports that it's not as reliable as the original GEBE though.

vooodooou · #5 (**permalink**) 08-22-2009, 12:12 PM

found this , looks like they are using mostly off the shelf parts.
V2 Belt Drive Parts Viza Motors - Push Scooters - Gas Motorized scooters - Electric Generators - Water Pumps - Viza Motors LLC

glacknoid · #6 (**permalink**) 08-22-2009, 02:49 PM

Nice find VOOODOOOU, it looks like Don Grubee is useing all the parts off the viza motors site with a few additional machined parts of his own.

tyrslider · #7 (**permalink**) 08-22-2009, 03:20 PM

Are you thinking about making one vooodooou? Or just making an observation?

Belt drives are utilized in many apps and no sense reinventing the wheel; they are, of course, adapting already existing parts. Trick is, this stuff, if not in the same factories, is being manufactured in the same regions of China; they can cheaply have the specs of their product altered to suit their needs. This alteration may or may not be apparent upon visual inspection (just 'cause they look the same....), furthermore, they may or may not be alterable to the end user in the way that they were to Grubee once mfg. is complete.

I only say this because, yes, w/ off the shelf parts, it is definately possible to make a working transmission. Firebelly and EZ do, Dax and Gebe I assume do. But it's the non off the shelf parts that all of these contain that take the effort to engineer, and therefore, make it so that if the end user manufactures one it is entirely more expensive (or time consuming) than just buying one.

I fully encourage everyone who wants to, to do so. The experience gained is likely to be immense, even when engineering/ reengineering just a few parts. You may have great ideas to offer! I guess just be realistic about your ability and resources to do so.

vooodooou · #8 (**permalink**) 08-22-2009, 08:04 PM

i am wanting to build a belt drive to jack shaft shift bike.
i just need the parts for the motor to a jack shaft. jackshaft will be welded to seat tube over to chain sprocket which will use sick bike parts too.

vooodooou · #9 (**permalink**) 08-22-2009, 08:15 PM

this will be a winter project. keep from getting cabin fever. lol

tyrslider · #10 (**permalink**) 08-22-2009, 10:35 PM

Sounds cool! By the time you get to the pedal crank you need a 35:1 reduction i.e. motor max's out at 7000 rpm's, cranks chainrings are spinnin' 200rpm's. This'll give you 30 ish mph in middle gear.

This means your belt side needs to be at least 6.5:1 or for a 20 tooth belt gear you need 130 tooth driven or you can go 20 to 70/20 to 70 w/ a 2 shaft trans. (3 counting the motor shaft).