Bandit,
For a SERA sanctioned event 45 miles is the rule. You will rarely see a SERA race go further than 35 miles. The terrain and speed averages of most SERA races make it difficult for a bike to make more than 45 miles to the tank. At the Acadiana Dirt Riders national last year the 3rd loop was 36 ground miles, I gave the riders a gas available at 30 miles out. Some of the converted MX bikes needed gas. This was a fairly open trail, but efficiency goes down with difficulty of terrain, ie. mud, logs, hills, rocks, tight trails, etc.
In the typical SERA race there arent too many fourth gear sections. :thumb:
The AMA requires gas stops to be no further than 50 ground miles at a national.
See you on the trail. :aj: