Are Open-Diff Chain-Drive Axles a Thing?

[Willie1]

Realistically - since we usually shoot for about a 6:0.1 final ratio with our driven pulley to rear axle sprocket tooth counts, one of these with the "best available" 5:0.1 ratio as a high gear would get us a final ratio with a little more top speed than we normally have, with 2 lower gears for crawling and hill climbing.

A potential downside to using one of these (with the driven pulley mounted directly to the input") is that you are locked into the internal ratios that come inside the unit - you can't just swap a sprocket to improve the ratio. You could, however, use the converter backing plate as you would on a mini-bike and run a chain drive to the trans-axle input, and change the ratio there.

I do think this would be a neat way to get a lockable diff function - among with reverse and other things - don't take my comments as bashing or being negative. I guess the next issue is finding them at a reasonable cost.

 

[l008com]

I've been thinking about this lately. Forget all those gearboxes/transaxles etc for now, lets just talk about that Pearless 100 open diff.

How well would it work throwing a single brake rotor on the body of the diff? Seems like that would work very well on a street cart but what about on snow covered streets or on dirt? I suspect this is going to be a tough one to answer because all trails are different and some might be perfectly safe to drive on, others might be dangerous. I'm thinking of a situation where I"m off the gas, I hit the brakes, but one wheel is either off the ground, or maybe not off the ground but in a position where it has most of the weight off so it has very minimal grip, and I just start sliding backward down a hill semi out of control. That'd be bad. But maybe the danger isn't as real as it seems? A single brake on the body would make this upgrade a lot easier to install if I do ever end up doing it.

 

[Kartorbust]

Well if you did dual brakes on the open differential, you could set it up as steering brakes, which can he utilized as a kind of limited slip. Would work best with hydraulic brake calipers. At least then if you're sliding on the snow, you could manipulate power to the wheels more easily.

 

[Willie1]

I've been thinking about this lately. Forget all those gearboxes/transaxles etc for now, lets just talk about that Peerless 100 open diff.

How well would it work throwing a single brake rotor on the body of the diff?

It works reasonably well on a street kart and miserably on everything else LOL. A lot depends on weight placement, tire tread design and ground surface, compounded by a lack of suspension to help keep the tires evenly planted - the result is the diff stops rotating, 1 tire rolls forward and the other spins backwards.

Personally, for any type of spirited riding off payment I would use a "hybrid" dual rear braking system in which the foot pedal applies both brakes, where a hand lever applies that side brakes. Crude examples below to show concepts. I would consider this a mechanical drum or disc setup only, piggybacking both control cables onto a single apply lever for each side. I guess you could really get creative (as in over-engineer the crap out of) enough to run "juice" brakes and run one master cyl on the foot pedal to control a caliper on each rotor, and a master cyl on each hand lever to control a second caliper on each rear rotor.
Not very budget orientated, but would probably be fun.

 

[l008com]

Realistically, I probably wouldn't need manual side to side control. That said, it would be nice if there was a super easy way to switch the bias. Like a lever you could flip that would disable one side or the other when you hit the regular brake pedal. Or a simple hydraulic brake lever going to two calipers, but if the calipers ALSO had a way they could be mechanically activated totally independent of wether or not they had fluid pressure. Like maybe something that was meant to be a parking brake but you could use in your (A) diagram.

If I do go this route though, unless it's super easy to do, I'll probably just go with normal two wheel brakes and do what I used to do 20 years ago when I first got this thing, and climb my *** out of the drivers seat and move it every time I get stuck

This question is moot unless I was going to go with a single diff brake, which I could see myself doing temporarily. Has anyone ever used a drive sprocket as a brake rotor? Like two in one? It seems like it would probably work ok for light duty use, except it would tend to get brake dust in the chain increasing wear.

 

[Willie1]

I have seen where the rear sprocket has been used as both the chain drive and the brake rotor. And yes, the brake dust contaminates the chain, and the chain lube contaminates the brake pads.

To get basic brakes to both rear tires would require 2 brake assemblies, a brake pedal and rods or cables to apply them.
If you use cables you could easily do something in this manner. Cables would run down both sides of the kart to the rear brakes.
Adding a lever and clamping it's cable to the pedals cable would allow dual braking with the pedal and single with the handles without much expense over the simple dual rear brakes.