PDA

View Full Version : Gearing Question

Jeff Stamper
03-01-2009, 05:02 PM
What gear should a Guy run at Norway in TaG with a Rotax ? Thanks:stickpoke:
Rick
03-01-2009, 08:11 PM
82 is probably a good place to start.
Jeff Salak
03-02-2009, 09:34 AM
Jeff

It depends on what size driver you have. Thought I read somewhere on ekarting you have a 12T driver now on your Rotax? If you do have a 12t driver you would need a 89 or 90 t in back. According to Ricks figure. I think he was thinking 11T driver? Not sure though!

Jeff
Rick
03-02-2009, 09:40 AM
Yeah Jeff is right, I was recommending 11/82.
rct25
03-02-2009, 10:10 AM
11/78


Roberto
D. Harrington
03-02-2009, 08:03 PM
Not sure on the gearing for Norway, but I would recommend running the 12 tooth driver. With the 11 tooth, you have to use the plain plastic bearing with this driver which wears out easily. the 12 & 13 tooth driver utilize a needle roller bearing that is more durable. Gear selection will depend on the driver and chassis set up. I would not exceed 14,000 rpm as the performance of the Rotax drops off significantly after 13,800 rpm. This Rotax has phenomenal midrange power which you want to optimize with your gearing selection.

Dave
avmaviator
03-03-2009, 10:53 AM
I don't want to thread jack but..... on a Leopard, with 11/80, what kind of rpm will that give me in the straight? I want to keep it 16,000 or less.
Rick
03-03-2009, 11:29 AM
That really depends on the driver. A national level driver like Brian Jacobsen probably gets it really up there since he's exiting the corner much faster than all of us normal people. I get 16000 or less with 11/80. Some guys like to 11/83 and rev it to 16,500 or 17,000. With 11/80, you have to carry more speed in all the low speed corners.
Jeff Stamper
03-04-2009, 06:52 PM
For all your future reference, the Rotax uses about the same rear gear as the other TaG motors, but uses 1 more tooth on the drive. Example, if you run a 11/81 on your Leopard, I run a 12/81 on the Rotax. Thats cool by me. Thanks Andy
JET Karting - Andy Finke
03-05-2009, 09:41 AM
I don't want to thread jack but..... on a Leopard, with 11/80, what kind of rpm will that give me in the straight? I want to keep it 16,000 or less.

I'd start with a 11/80 as well. More teeth on the axle will give you more RPM. As you get smoother and faster through the corner, you'll carry more speed into the straight. This will increase your rpm at the end of the straight, and you'll end up having to either drop teeth, or live with more rpm.

I recommend you keep the Leopard below 15.5k unless you are racing. They last a LONG time there.

Above 16k makes a little more power IF your are capable of driving close to track record times. However, 16k will cut engine life in half or less. 17k makes it a two or three hour motor...


Andy