# Go Kart transmission



## iti_uk (Oct 24, 2011)

Snakub said:


> I just recently put my e kart back together I switched from a 225 amp curtis controller to a diy paul and sabrina controller. I have snapped multiple chains with the curtis so I switched to a belt drive and thought it would relieve me of those headaches. Now the timing belt that I put on the kart just slips even with it as tight as it gets. So now I am forced with either re doing everything with a cog belt, getting a thicker chain drive, or installed some sort of transmission. I think after the work that's already in it I would be happiest with a 2 speed transmission. My question is what is normally used as a transmission on a go kart? Because I have looked on Google and there doesn't really seem to be anything I can commercially buy. Is there some diy route can I build a custom transmission?


How about a double chain?

Sorry, I don't know about shifter-kart transmissions.

Chris


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## MalcolmB (Jun 10, 2008)

Snakub said:


> I have snapped multiple chains with the curtis:


Hi Snakub. It sounds like you need a bigger chain. What size are you using now? It would help a lot if you could post some photos of your current setup.


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## mizlplix (May 1, 2011)

We used to cut a regular motorcycle transmission off from the motor part. then T.I.G. weld a mounting plate and do some input gear adaption to get a stand-alone transmission. 

BTW: the #50 roller chain is good for 65HP or so. 750CC and up motorcycles have #50 chains.

Some early 3 speed car transmissions were small also. They can be shortened and the tail housing can be removed.

Example: A Crosley had a Very small 3 speed top shift trans with no tail housing at all.










It is a lot smaller that it looks in this pic.

Miz


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## Woodsmith (Jun 5, 2008)

How about a motorbike transmission? I am assuming that you would reverse electrically with reversing contactors.

Many modern bikes have their transmissions integrated with the ICE but I am sure that seperate trans are available.
When considering using a BMW K100 for my trike I found that the trans looked useful once the swing arm was removed. It had a clutch spline on the input and an output spline on the other end for the driveshaft, that could be used with a sprocket. It makes a nice sequential 5 speed that could be driven from either end.

For my tractor I have a single 1/2" pitch chain from the motor to a Wheelhorse transaxle. All the torque is inside the trans with the chain running at high speed.

For my trike I have planned for a duplex 5/8" chain with direct drive.


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## Snakub (Sep 8, 2008)

I have looked at the motor bike transmission and the don't look very adaptable and are very pricey maybe I look around at the junk yards if something pops ditto for the Crosley or anything similar. For now I guess I will go with a #50 chain since the components are cheap enough but check out this guys diy go kart transmission its just nothing sort of genius even though I think it would take me a while to get something like this done and adapt to my set up it may be worth a try. Although I still have yet to see a video of it in action.

http://www.thepixelpump.com/widdershins/how-to-2speed-transmission.php


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## Woodsmith (Jun 5, 2008)

Interesting, using the bolt heads as the drive dogs. It works fine, WW2 Scammell winch drives worked the same way. The big problem is not being able to shift when moving and also difficulty lining up the bolt heads with teh holes to engage the dog clutch.

If the bolt heads had a cone or dome top added then that would make it easier to engage. You would only need it on a couple of the bolts.


I picked up a BMW K100 gearbox without the swingarm for £10 on Ebay.
Here's mine with swingarm.









Another thought is the Lada Niva transfer box.
It is a full time 4x4 box so it has a locking diff inside and two speeds. It would make a great 2 speed axle with diff lock.

















How about the transmission from a 2CV?
Small, light, inboard disc brakes, 4F1R.


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## MalcolmB (Jun 10, 2008)

Some great ideas there Woody. I was getting all excited over that Lada transfer box. The ratios are just about ideal and it would make an interesting alternative for a Mini, but then it occurred to me that you would need to stop to change gear, wouldn't you?


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## Woodsmith (Jun 5, 2008)

MalcolmB said:


> Some great ideas there Woody. I was getting all excited over that Lada transfer box. The ratios are just about ideal and it would make an interesting alternative for a Mini, but then it occurred to me that you would need to stop to change gear, wouldn't you?


You would but you could gear it for urban and motorway speeds.
That was my plan at one point, that I could change gear at a stop if I knew I would need the higher speed soon.


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