GEBE And Friction Drive Combination

[2Fat2Pedal]

Gear Work-around

5-7,

I started a homemade belt-drive project and planned to use the GEBE gears/belt. The GEBE drive gear has 5/16 fine thread on the inside. I have a 78mm clutch bell with M8-1.25 thread. 8mm is pretty close to 5/16 so I cut the head off of a 5/16 bolt and cut M8-1.25 threads on half of it. It was a pain and I had to "lathe" down the end that I cut threads on using a drill press and file.

The picture shows the axle scrwed all the way out. Of course you would tighten it so the gear butts up against the bell when installed.

Haven't finished the build because bike was stolen from my garage. Don't know if it will work. GEBE full kit would certainly be easier.

2Fat

 

[5-7HEAVEN]

2Fat, can you explain how the rest of your build would be? Was it also being mounted onto a Staton/BMP housing?

 

[2Fat2Pedal]

Originally, I was going to fab a mount similar to GEBE. However, my under-engine fuel tank interfered with the tire using the standard GEBE belt. The GEBE transmission has a long nose on it allowing the engine to sit far enough right so the tank misses the tire. So I was either going to mount the tank separately or maybe try an approach like you are. Too bad bike got snatched (with wheel gear and belt) before I got to finish.

 

[5-7HEAVEN]

Aint that a ***** when your stuff gets snatched, man! Dang!

JMO, I think my approach is the simplest for my application. It's also the cheapest if you start out with a friction drive kit.

Just can't see plunking down $350 for the GEBE kit, especially if the belt drive doesn't work well for me.

People need to look for cheaper ways to do stuff. It makes it more interesting and satisfying as well.

 

[2Fat2Pedal]

I hear ya. Good luck with the project.

 

[5-7HEAVEN]

Hey thanks, 2Fat.

I found an online company that fabricates custom pulleys. I inquired about them making a steel drive pulley with two siamesed pulleys, one 14-tooth and one 15-tooth. That way, when I want to change drives, I just loosen the drive pulley, line up the one I want, tighten everything up and

Voila! Different gearing in minutes!

To make it easier to replace a broken belt, I will secure a spare belt around the axleshaft, making sure it doesn't rub against moving parts. If/when the main belt breaks, simply drop the spare belt into position, adjust tension and motor away in a few minutes!

 

[5-7HEAVEN]

Still Looking...

I purchased the HTD-size GEBE drive ring for $40 and installed it onto my HD wheel. Still haven't found an HTD-type pulley with 1/2" bore that would slip onto the shaft. One company advertises on their website that they had them, also custom made pulleys.

They lied.

So I bought this 15-tooth aluminum drive pulley on Ebay for $8.99:

http://cgi.ebay.com/CNC-SERVO-STEPP...tem&pt=LH_DefaultDomain_0&hash=item4ce9faae8c

It has a 1/2" bore, so should slip right onto the shaft. Unfortunately, it's XL-type, not HTD. Pitch size is almost identical, so I'm just gonna mismatch and try the pulley.

Still looking for the right pulley. When I drill new engine mounting holes and get the right-size belt, I'll be done.

I WAS gonna order the GEBE XL-type drive ring, but the HTD belt seems to be rated at TWICE the breaking strength.

Belts are very cheap($4.00+) online and pretty easy to find in size, but not with kevlar. No need for a superstrong belt yet, until this prototype is a success.

FYI, I emailed a large pulley/belt supplier. Hopefully they can custom make a 14-tooth steel pulley with 1/2" bore, keyway and setscrews...inexpensively.

 

[darwin]

Would a pulley off of an alternator work?

 

[5-7HEAVEN]

I don't think an alternator pulley would work for me. Besides not having an HTD 5mm pitch with 9mm width belt, the overall diameter would have to be less than 1.375". That way, I can install the assembled shaft thru the friction housing's 1.375" bearing holes. The 14-toothed pulley I had in mind has a .877" diameter.

I emailed a pulley supplier. Crossing my fingers that he can custom make the 14-tooth pulley at a reasonable cost.

 

[TREEWK]

5-7,
Did You Have Another Thread On This Build? Seems I Had Posted Pic`s Of My Clutch Hub Set Up For The Htd Motor Cog. I Will Post Pic`s For 2fat (thought He Meant Me = 325!! Lol).

Here Is One Idea For U, It Could Work. Have Your 1/2" Drive Shaft Cut Down And Threaded To 5/6" Fine Thread = No!!

Better Yet Have It Machined Off On Lathe An Inch Or Two= What Ever Is Need To Align With Wheel Sheave, Bored And Tapped For The 5/16 Nf. Now The Piece You Cut Off Can Be Drilled And Tapped . Buy Long Grade 5 Allen Set Screw. Screw It Into The Shortened Drive Shaft, Screw You Motor Cog On. And Then Screw On The Short Tapped Piece Of Drive Shaft And Your Outer Bearing And a Broached Split Collar with a short key.

When You Want To Change Motor Cog`s Use Vice Grip On Shaft Collar. U Could Also Install A Broached Split Collar On The Motor Side Of Drive Cog To Gripe It When Tighning Or Removing. I Say Broached So You Can Install A Piece Of Shaft Key So It Won`t Slip On Shaft When Install Or Removing.

Imo The Belt Will Strip The Teeth Off Before The Shaft Gives Trouble. Also U Can Buy The Bearings With 5/8" Id And Go To 5/8" Drive Shaft And Use 3/8" Nf Allen Set Screw. Bore And Tap Cog (with A Lathe For True Accuracy. I Think You Need A Spring Tensioner, Not Too Strong Of Spring As It Will Be Detrimental To You Wheel Sheave.

I Think We Can Do This!! Trust Me, When I Fall Back You Can Catch Me! Geico. What Say You?? Lol. Later Guys. Ron