I am racing on a course (Hare Scrambles) in a few races that has big open areas to really open up the 400ex. Could you guys tell me what the best gearing setup is and what is the tallest I can go and still pull 5th to the top. I have stock tires and only a modified pipe and K&N airfilter.

Thanks in Advance.

 

I don't ride a 400ex and I'm not sure about the stock gearing, but maybe I can give you a little info for a starting point. My Warrior's stock gearing is 40/13. I run a 15T countershaft sprocket for top end. I ride mostly open desert & tight tech trails (50")in the cool weather & woods in the summer. With the 15T & stock rear, I still have more than enough low end torque, even in the tight woods or down in the tech & rocky terrain, yet it does provide more top end. In fact, I'd try a 16 T but I doubt it would fit without altering the case.
I doubt you'd have any problem pulling that tall of a gear combo even without knowing your present gearing. You may even wish to go a little higher, depending on your style & the space limitations on your machine. Of course you could also go with a smaller rear sprocket such as two teeth. I know you realize that any drastic changes like these may require a new chain also.

 

stock tires, 16t front sprocket. It works for me.

Steven

 

Do you lose the case saver with the 16tooth or do all the parts still go back on?

 

All you have to do is grind the case saver down, just enough to clear the new sprocket. Or you can just take it off it you want. I just ground my down a little.