Rear rack Greyhound mountain build

[powdersummit]

I'm glad that everything is working out for you on your build. I've been meaing to get on an post but just haven't had much time. I'd love to see some video of that thing especially the acceleration. 50 mph is kinda fast on a bike. The gearing may be good if you can cruse at 30 with a lower engine speed for reduced sound. It's also awsome that you can take off from a dead stop in either gear and also get that kind of speed. Most of the time with something like that you need to be able to shift through gears to get up there. That engine must have a pretty flat torque curve to be able to do that.

What would you say would be the dry weight of that engine minus the fuel tank? I might have to look at getting one if they don't weigh too much and I could replace the carb with something else or add a fuel pump to move the tank to a lower position.

Carl

 

[4950cycle]

Carl, post #25 from ibdennyak shows you where to get a fuel pump. And according to post #39 from yours truely never said I had her up to 50 mph. I said I approached 40 mph and didn't have to peddle off the line. I think its "capable" of 50 with a smaller pulley where the 8 inch is now. But I'm sure I would have to peddle off the line with that setup. Or figure a way to shift on the fly. And as far as the weight of the naked motor, I would put it at 14 to 17 lbs. . I weighed the naked motor but can't remember exactly what I saw. It was a couple months back. I would do it now for you but its all put together. I will run thrue my written data and see if a wrote it down.

 

[4950cycle]

It shure is funny no one seems to be interested in this MB anymore. A guy might think the thread was invisible. Hmmmm

 

[srdavo]

Heh.... not invisible...... you have over 1600 views!!!

I like it.... especially the 2 speed.

your high gear ought to click along with some great fuel mileage...

& your low gear should climb any hill you want......maybe even a tree?

I'll be looking at your design more .... I'm re-doing my HF drive-train on my trike.

 

[4950cycle]

Thanks for letting me know I didn't tick off the moderators or something else that might have gotten me nixxed on this site. I was starting to think they may have made my two or three threads invisible. This muti pulley idea would be a perfect drive train for a trike srdavo. But I am thinking of a two in the rear trike. Because there is more room to put more pulleys (more ratios). You would be able to put at least three with no trouble. Maybe even four. I'll never go back to chain. This is so much smoother and maintenance free for the most part. And no oil or grease slinging. They say it gobbles a little more power than chain though. I'll pay the price gladly its so much better IMHO. I wanted to go with a Nuvinci hub. But wasn't convinced they were unbreakable. So I devised a system with more than one ratio I can fix with basic parts if it malfuctions. And this is what I came up with.

 

[rustycase]

I'm real interested in your work, 4950 !
Need to learn abt belts, and seems like you are the man to ask.
Don't know the right questions yet, though.
6.5 greyhound on the way...
rc

 

[4950cycle]

RC, With 6.5 hp, That opens a whole new world as far as ratios !! Heck, I'm only running a 2.5 hp Greyhound. With 6.5 hp you could run a 4.5 to 1 ratio (unless you were 270+lbs.) and hit 60 or better in a full tuck for God sake. I am running about 20-21 to 1 for my low gear and about 9.5 to 1 for high gear. With so much extra hp you have a lot of freedom with your ratios. Lotta motor for a bicycle !

 

[loquin]

You could possibly replace the clutch with a max-torque torque converter and add a spring-loaded belt tensioner, which would get you a near 2:1 ratio, automatically.

 

[4950cycle]

BTW, Belts were an unknown an kind of spooky to work with at first for me. If you make any fairly big pully/belt size mistakes you pretty much eat it $ wise ! Couldn't find hardly any guys that had worked with them on the net. So I was on my own . Chains and sprockets can be a little cheaper to work with and easier/cheaper to adjust your ratio by adding a tooth or two. Belts you have to know pretty much what your goal is from the start. Read, harder to adjust your course. I have used a larger motor like you and I have used smaller motors like mine. So I am starting to get a natural feel for what is needed to arrive at a certain ratio needed. Not saying I am flawless but at least have an idea of what to do for a sucessful ratio per power available. I've learned from the people on this and another site plus personal experience.

 

[4950cycle]

I was going Nuvinci or a Comet tourque converter at first myself. But also wanted to try a brainstorm I had from looking at the internals on a drill press. And I also thought the torque converter idea might be heavier than I would like. Between the motor and torque converter on a rack mount, WAY to clumbsy balance wise ! My drive train may be lighter than it looks ! And I have an idea to lighten it ferther. But the torque converter doe's have almost endless ratios. I am attracted to that idea..