Diesel enduro test drive video

D_Mold · Post by **D_Mold** » Tue Mar 11, 2008 5:20 am

http://youtube.com/watch?v=1eYZZ3ZhBII

If that link doesn't work, type in diesel motorcycle test

For the time being, I can't afford a comet clutch. So I decided to invent something stupid but cheap. A two speed belt tentioner transmission with suicide shift lever. It works great, but takes some getting used to. Feels like a dump truck with this lever! Today was the first day I got a licence for it, so I spent hours ripping around. I topped out at 45mph which was plenty fast for me. Got lots of extremely weird looks as I clunked by in the middle of winter with clouds of black smoke following me. The huge hand shift and foot clutch also added to the looks!

Problems I encountered were that 1st gear was too high. Belt is already worn because of friction. But with a lower gear, it should be fine. Also the so called "alternator/starter" I've read about doesn't do anything. Stalled out in the middle of nowhere with a dead battery and a broken pull start. But all in all, I've had an absolute blast! Will post more videos when I have time.

johnfireball · Post by **johnfireball** » Tue Mar 11, 2008 11:29 pm

Coooooooooool I cant wait to do mine.
John

Post by **Byrdman** » Tue Mar 11, 2008 11:36 pm

Very nice.

I love the fact that you built an enduro. I wonder how it'll be off road?

balboa_71 · Post by **balboa_71** » Wed Mar 12, 2008 10:27 pm

D_Mold,
I've been in your shoes, trying to get out on the road to feel the engines power, dispite not having a transmission

Problem is, the transmission/clutch makes or breaks the performance of the engine. The two major problems with 3,600 rpm limited diesel engines is there is not a good transmission available that can be used to get the power to the rear wheel and the second is finding a good clutch.While some may argue that there are 5/6 speed tranny's available (for Harley applications), you will not see many of those used on home made bikes ($$$). Comet trann'ys are the most available, and it's what a lot of us use. Problem is the belt being used as a clutch wear material, which it is not best solution, nor it the very expensive drive units aluminum "cones" being the mating surface for the belt. Both rubber (and its variations) along with aluminum make for crappy clutch components. While the Comet is a very good system (when it is used as designed), it is a not good for quick off the line starts and does not hold up well to lots of road dirt. Both rubber and aluminum melt at low temps, so one has to keep from burning the rubber belt when taking off from a dead start. While there can be a good amount of friction between them, add some water, and that goes out the window.
I did a simular belt drive experiment using a B&S 8hp gas engine sittng inside the crotch of a moped. I had an idler pully simular to yours rigged where the belt drove a shaft down where the pedels used to be and then a common chain and sprocket drive to the rear wheel. I tried centrifical clutches, first..... (they suck) and then used the belt on aluminum pulleys that didn't suck quite as bad. The belt lasted as long as yours did

So, that brings us back the the original problem: transmission/clutch. Clutch can be solved with a nice dry motorcycle after market unit, but finding a cheap multi speed tranny isn't going to happen.

I'd suggest you go with a Comet when you can afford one. Get a 500 model and gear your bike to run around 50/55 mph. You'll get good life out of your Comet and not stress your engine and drive train!

Cris

D_Mold · Post by **D_Mold** » Thu Mar 13, 2008 3:09 am

Yeah, I agree that a transmission makes or breaks the performance. The only problem is I have no money whatsoever. A comet would be good if I could afford it. What I would like over anything though is a 6 or more speed transmission. I live in the praries, so shifting isn't done very often. Has anybody out there used an old engine/transmission unit and cut out the engine part? For a future project, I might try that.

Although pulley tentioner transmissions have their limitations, I've had pretty good luck with them. This picture is of my 5hp mountain bike with two speed belts just like my diesel.

This absolutely blew the centrifugal out of the water. I went through a few belts before I found the key issue. The most important thing is the first gear. On this bike, its very low, so starting is easy on the belts. Then second is much higher, but doesn't have to slip to engage. On that mountain bike, the $2 belts have lasted 700km of 50km/h winter/mud driving! They're still in good shape. The only thing that hurt those belts was the -50 degree mornings.

On the weekend, I'm going to make a lower first gear for my diesel bike. I'm estimating that the $2 first gear belt will last 300km, while the second gear belt will push 500km. This system is fine for now, as cheap belts are readily available...(and I've fallen in love with the suicide shift!).

andrewaust · Post by **andrewaust** » Thu Mar 13, 2008 3:19 am

Looks like a fun project - will be interesting to see how it runs when you get the primary drive sorted.

Yeah I know what you mean regarding the stator if you need to keep a battery charged for starting. Luckily chuggy's kick start with the chain primary. 7-9amp stators are not good enough to power lights and charge a 20AH battery at the same time, although it's just holding up with a 12AH battery.

I'm not sure of the information, but heard the Yanmar L100 has a 25amp stator available and supposedly fit the clone Yanmar diesels, although I think its for the 406/412 cc version.

Cheers

Andrew

Sphere · Post by **Sphere** » Mon Mar 17, 2008 9:07 pm

Well, there's plenty of Enfield diesel conversions with a 4-speed transmission box so I'm wondering if it's really such a show stopper?

Also, you could use the 5 disc Enfield clutch if the current one doesn't suit your needs. Well, maybe I'm biased.