Motorcycle Powered Kart: Father Daughter Project

[farmer92]

just use a golf cart diff then?
There are many with lateral diffs that are driven by a snowmobile type cvt clutch.
all you would need to do is replace the driven pulley with a sproket.
Those golf cart diffs are tougher than they look, my cousin hooked a 440 sled engine to one and that thing hauls.

 

[irk miller]

Roadstercycle reverse gearbox with TH400 splines, so you can run a Chevy drive shaft yoke any rear end.

 

[Tune-A-Fish]

BMW r100r power and modified swingarm or mystery trike rear end

 

[redwillissuperman]

Simple- FSAE. Torsen diff and two cv shafts. Use Mazda Miata Uprights.

 

[Tune-A-Fish]

Full on threadjack but cant resist

This power seems to be made for these applications.

 

[Dale]

dif·fer·en·tial
ˌdifəˈren(t)SH(ə)l/

Gentlemen.

I turn my head for one second and there's a bunch of great ideas all posted up! HA ha brilliant. Every single comment posted was helpful.

Spent most of the day mulling over what you guys have suggested, hinted at, and flat out worked out for me!

Of course you are not making a dragster, but my money says this will be a problem, not merely a nuisance. You could simply drive only one of the rear wheels which would eliminate the problem, but if you have a notion to make this vehicle more powerful down the road you will again be looking for some form of final drive that drives both wheels. My guess is that, with the size, weight, and Hp you look to be heading toward, the lame sounding one wheel drive would work just great.

jpmobius, your measured approach, and consideration of the big picture stuff here is spot on. The one wheel drive scenario will be my back up plan.
It alleviated some of my "panic" ... I've been sweat'n a bit on this diff issue.

Making the best trade offs often results in what turns out to be the best engineering.

Beautifully put.

-------------------------------------------

My brain block was the shaft / chain issue, and how to marry a [chain / sprocket system] with a [shaft system].
Did a bit of basic research on how a diff actually works. Whoever invented that thing is a genius. Truly.

Here's a great little vid that explains how it works, if you're interested.

https://www.youtube.com/watch?v=SOgoejxzF8c

I guess these components are called different things, depending on what side of the pond you're on, but this is a good illustartion.

• Dont need the pinion drive
• Dont need the ring gear, that .... can be changed out for a rear sprocket
• Fabricate a rotating cage out of a piece of billet
• Let the rotating cage ride on a bearing on the left axle
• Rear sprocket bolted to the rotating cage
  

Heres a loose mockup to show the idea:

A - BEARING
B - ROTATING CAGE (arms wont be that long, just to make it more visible for demo purpose)
C - REAR SPROCKET
D - LARGE / SIDE GEAR
E - SMALL GEAR
F - LEFT AXLE
G- RIGHT AXLE

And a couple of pics in situ.

So I need the 4 gears. Need to research the donor. HUH?

 

[DohcBikes]

If im not mistaken, some riding lawn mowers have open differentials which could be a wonderful place to start. The extra gears are called 'spider gears' or 'side gears'.

 

[irk miller]

dif·fer·en·tial
ˌdifəˈren(t)SH(ə)l/


My brain block was the shaft / chain issue, and how to marry a [chain / sprocket system] with a [shaft system].
Did a bit of basic research on how a diff actually works. Whoever invented that thing is a genius. Truly.

That would be Karl Benz. He also invented the double pivot steering system.

 

[jpmobius]

Looks like there is a lot out there:

http://www.peerlessgear.com/node5380.aspx?nid=300843

http://www.ebay.com/itm/like/390973290339?ul_noapp=true&chn=ps&lpid=82

 

[DohcBikes]

^awesome. You just stepped up the street atc game big time mobius

 

[irk miller]

A typical Formula 1000 setup with a split sprocket and a Quaife ATB open differential. You could probably salvage one from an VW, Audi, BMW, etc. By allowing the drive wheels to turn at different speeds, it improves cornering.

 

[Brodie]

Why not just turn the engine to its side and machine a drive shaft to slip over the sprocket shaft and run into a diff?

 

[redwillissuperman]

Took about two seconds to type "FSAE Differential" into google images. Actually I just typed "fsa" and it came up. This has been solved 1million times by kids around the world.

 

[DohcBikes]

^If so simple why'd you have to Google it

 

[irk miller]

Formula SAE (FSAE) is fundamentally doing the same thing, except they typically use a torsen differential. You can also mount your brake rotor with your differential...

 

[irk miller]

 

[DohcBikes]

^Trike conversion differential? Thought about that too, no Google required

Most of these suggestions are mighty large for a 13 hp engine. That's why I suggested a lawn tractor diff. Great suggestions nonetheless.

There are also a lot of open and even selectable locking diffs to choose from in the atv world but almost all are shaft driven.

 

[Tune-A-Fish]

Does that come in a double switched locker so I can command the wheel I want traction to

 

[DohcBikes]

Does that come in a double switched locker so I can command the wheel I want traction to

That's a tall order, it would almost take hydraulics to accomplish a choice in the driven wheel, but as you posted that, I was editing my above post to include that there's lots of selectable locking diffs in atvs. However its an on-off type operation.

 

[Tune-A-Fish]

4 mini X planetary drives and a joy stick, then you only need a 5HP utility power plant and a pump... no speed records in rock "crawling".