How Does the GEBE System Work?

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smapadatha

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How Does the GEBE System Work?
(An Introduction for the Curious, the Spurious, and the Furious)

The purpose of this article is to explain how the GEBE bike engine solution works, for those who have never owned one or seen one.

Golden Eagle Bicycle Company (bikeengines.com) sells gas engines that can be mounted on a standard bicycle, and mounting kits/drive system for getting it on there. The GEBE company doesn't manufacture engines. They re-sell small (about 50cc and under) engines from Tanaka and Robin/Subaru. The quality of these engines is excellent.

GEBE will sell you:
1. Just the mounting kit/drive system, if you already have an engine.
2. The engine and mounting kit/drive system.

They also have other stuff like spare parts and bicycle wheels (rim, spokes, hub) that are built to take the punishment that an engine dishes out to a bicycle.

There are several ways to hook a gas engine up to your bicycle. The GEBE company uses a belt system, which many people consider to be the most reliable. (Opinions vary on this topic. Some people prefer a chain system or a friction system, but GEBE doesn't sell those.) The heart of the GEBE system is not the engine, which they only re-sell, but their "drive ring".

The GEBE drive ring is a molded plastic wheel, 17 inches in diameter (outside diameter) and 1.5 inches wide.

1815_drive_ring_on_wheel_from_front2_1.gif

1815_drive_ring_on_wheel_from_45_closeup2_2.jpg


The drive ring has slots molded into it which allow it to literally snap onto the spokes of your rear wheel, and teeth molded into it so that it grips the toothed belt they give you. It may not look like it from the pictures, but the slots on the ring snap onto 14 gauge spokes VERY securely. It's not easy getting the bleeping ring off, even when you want to. GEBE sells a 32 spoke version and a 36 spoke version of the drive ring.

In most cases, the GEBE drive ring will go on the left side of your rear wheel; that is, the "left" side if you were sitting normally on your bike. It's possible to mount a GEBE kit on your front wheel, but few people do this or recommend it.

1815_drive_ring_on_wheel_from_top2_1.gif


Note that the drive ring sticks out from the side of the wheel. That's necessary so that the drive belt can slip over the ring and attach to the engine shaft. However, a wheel with a GEBE drive ring on it is so wide that it will not fit on all bike frames. For that reason, it's a lot easier if you buy the engine kit (and even a rear wheel) from GEBE *before* you buy your bike. If you already have a bike, you can measure your frame to see if the drive ring will fit, but it's a lot easier to have the wheel with the drive ring on it beforehand.

The GEBE mounting kit/drive system has the following main parts:

1. A heavy steel bracket that attaches the engine to your bike frame.

Installing a GEBE kit is like putting on a rear bike rack. The weight of the engine rests on a main bracket that attaches to your rear axle, although some people mount the main bracket directly to their frame.

1815_main_bracket_full_wheel_1.jpg


The kit also comes with a stabilizer bar that prevents the engine from moving forwards or backwards. One end of the stabilizer bar attaches to a bolt on the engine and the other end attaches to your fender mounts or anything else around the back of your bike where you can thread a bolt.

1815_main_bracket_and_stabiizer_1.jpg


2. The GEBE drive ring.

3. A "toothed" kevlar belt. They currently use one made by Gates.

1815_gebe_toothed_belt_1.gif


4. If you buy your engine from GEBE, they will put a small gear on the engine shaft.

1815_gear_on_gebe_engine2_1.jpg


The basic steps for installing a GEBE kit are:

1. Snap the drive ring onto the spokes of your rear wheel.

2. Attach the engine to your bike using the main bracket and stabilizer bar.

3. Loop the kevlar belt around the drive shaft and drive ring.
3.1. The gear on the engine drive shaft meshes with the kevlar belt.
3.2. The kevlar belt goes around the drive ring.
3.3. The drive ring is attached to the spokes of your rear wheel.

MAKE BIKE GO!!

4. Attach the kill switch and the throttle to your bike. If you buy your engine from GEBE, it will come with a nice kill switch and throttle already attached.

5. Add gas and oil and try not to crash into stuff.

From the steps above you might assume that installing a GEBE kit is a piece of cake. Well...it should be. One the one hand, we aren't building the International Space Station here. On the other hand, a bicycle must meet certain requirements before you can GEBE-ify it. I will cover those in another rant...I mean post.
 
absolutely a gem of a post, smapadatha...thanks very much 8)
 
Is it possible to use the Gebe system with the motor installed in the frame?
 
Excellent platform to build upon Sam

I just put on 2, the second a lady's coaster brake, which require a tad of "frame squeezing", and want to point out 3 parts for emphasis.

The key is the spokering, install it in the "clock method", 12-6-3-9 positions, to torque it down and make sure the gap is correct.

2.125 tires are tricky to work with, the belt can touch the bulge of the tire, and fray. Washers are used on the drivering side of the axle to allow slight changes in centering the belt on the "small gear"/drive gear, and you can adjust the axle slightly to push the tire at clear of the belt.

Smaller tire sizes do not have this problem, only the fattest standard size.

Also, the two straps that came with these latest engines had to be reamed slightly to fit onto the engine mounts.

21_2007_0315brackets0002_1.jpg


I usually use either the second or third hole on the strap, you might use the fourth or first, depending on the bike.

Check the strap out on the mount, see if it will slip on before starting that part of the install. You might have to take a drill bit to the hole, so it will make it fit at a crucial moment.
 
skyl4rk said:
Is it possible to use the Gebe system with the motor installed in the frame?

Well, the simplicity it that the rack, fit over the axles, makes the belt measure perfectly.

NO varience on the distance from the axle to the "small gear"-drive gear.

That couldn't be achieved with all the different bike frames and lengths.

Installed properly it's pretty flawless, those belts are tough.
 
Thank you for the wonderful resource, Smapadatha. I direct people to this link at least once a week who have questions about how the kit works.

Vaughn
Gebe
 
Not a very dependable looking kit. I got rid of mine as soon as I got it and compared it to other kits. Fortunately advertisements like this help it keep an inflated value so i got rid of mine easily.
 
Yeah I looked at their weibsite and they seem awefully expensive when compared to other kits that offer the same perfomance and reliability.
Nice post though. You made it seem easy to install.
 
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