Custom Karts Forum

I know that most C-Ks are direct drive with a solid axle, but it occurred to me there must be a simple way to cost-effectively add a diff.

In researching the notion I discovered that quite a lot of other types of karts - go-karts and ATVs and even FSAE racers - use chain-driven diffs. Some even have LSD functionality.

This is one idea I've found, if anyone is interested in the concept.....

Terrapin diff

Yet again Mark, another thing that has been discussed a lot on here.

Well worth discussing but the challenge of building within self imposed weight and cost restrictions is also relevant here.

On the Gitterville site I've noticed quite a few of the karts have provisions for driving one or both wheels. Considering the narrowness of the chassis we're building and likely application on dirt or grass are differentials even useful? Lots of low budget race cars simply weld their differentials solid rather than spending the $$$$ on limited slip units.

I would think that one wheel drive, or a differential would be useful mainly in parade type situations where you're going slow on pavement. Once you start wanting to go faster and slide around corners a straight axle would probably be preferable. But this is just my speculation based on the racing karts I've built in the past....

Cheers,

think this could be used on a cycle kart?

I've heard of similar things being done with motorised tricycles, but the question would be whether or not it would be durable enough in a cyclekart. It would be better to base a drive around two heavy duty flanged freewheels intended for use in tricycles which would make for a far neater assembly without the need for overly long bolts to hold everything together.

I've got one of these flanged freewheels which I purchased a short while ago to rebuild the axle on my own tricycle and they are nice pieces of work.

---

"The French follow no one, and no one follows the French"

Anne- do these flanged freewheels share a thread pitch with a standard freewheel? And what is the diameter of the outside flange? I've found the flanged freewheels online for 25$us dollars, and they're used on motorized bicycles, so they definetly would hold up.

Charlie, the thread pitch is the same as a standard freewheel and the diameter of the flange is 94mm.

---

"The French follow no one, and no one follows the French"

I'm almost certain that using those flanged freewheels and that design I found a person could make a usable differential unit, and if you add a pair of these for each axle
http://ww.atomiczombie.com/FDAX34%20Trike%20Axle%20FreeWheel%20Adapter.aspx
You could run disc brakes on each side from a dual pull setup to stop. A person would need to turn the end of the axle down from 1 inch to 3/4 to fit the adapter though

Non-spec build question, moving this topic to Custom Karts Forum

Thanks
Skye

---

Webmaster, The CycleKart Club

Essentially it would work but in a curve you would still have only one wheel driving. I would agree that if that wheel slipped the other one would catch. The pull start device would accomplish the same result. Which would be easier or cheaper or lighter weight?
Fred

---

Fred V
www.jzrusa2.blogspot.com

Atomic Zombie is offering you a part for a 3 wheel bicycle that only drives one wheel, there is no differential on such a trike.

What you should like is called a spur gear differential. Such as this should be. I haven't taken one apart, so I can't prove it. But that's a standard type for this application.

http://www.northerntool.com/shop/tools/product_35768_35768

The Terrapin differential is for a chain drive racecar with anywhere from 90-170hp, not sure it's the best thing for a little cyclekart.

I've got one of those they're a nice diff for light vehicles with chain drive. The most important thing to remember is that they need a bearing mounted stay arm mounted on the axle shaft on the same side of the diff body that carries the drive sprocket.

---

"The French follow no one, and no one follows the French"

Some of the Gittreville Karts have tried the Northern Tool differential. Their experience is that in a racing environment the differential failed The Gittrevile site has a description of their experiences.

Correct, but if you use 2 of them connected as shown they make a "kind" of diff. It is an idea worth trying.
Fred

---

Fred V
www.jzrusa2.blogspot.com

I will add something to consider with respect to differentials. Gas powered golf carts have a gas engine connected to a differential through a variable ratio belt drive . I used such a package to build a mini truck to use at our farm It has a 9 hp kawasaki engine with a rev limiter and will go 18 mph before the limiter kicks in. The entire assembly rides on a subframe complete with springs. Just add frame & inspiration car body. With larger wheels, remove the governor and you have a kart with a respectable speed.