I found that the best Bag for the 2015 CRF250L is the Nelson Rigg tail bag. Here's a link https://www.nelsonrigg.com/luggage/tail-bags.html You mount the rack on your 250L then the Bag is removable.
Now i've found that the best RACK is the ManRack Utility Rack Here's the LINK http://www.manracks.com/#!honda-crf250l/cjhw Much better than the Moose Racing 1510 - 1099 rack The specific Nelson Rigg bag is the CL 1060 S Finallly i'm figuring it out !
Those $20 tie down brackets that mount to the front fork are a great idea. Might have to pop on those. ..