Gearing needs to be tuned to your application much like jetting and just about everything else. You should gear for the fastest part of track. My last track day I ended up at 16/40 and was touching 13000 in 6th gear at my braking point. Thats how I gear for the track. I'm no expert tuner but it works for me.
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1995 A kit TZ 250
1994 Rothmans NSR 300sp SOLD
1998 RM 250 freestyle/motorcross
1998 Meathanol burning CR 500 AF super retard/motorcross/sand dunes/play bike