I change mine ever 5K, but much depends on your use and set up. If you are not using in dirty conditions often and maintain your air filter well then you should be good to go to 5K.
If you trail ride a lot in dusty conditions and still run a stock paper style filter I would say 3K intervals.
Best to watch your oil breakdown as you put on miles. Check often, although at 5K intervals I am never even a tick low on the dipstick.
Here is what I do to monitor my oil. When checking first wipe dipstick with a clean white paper towel. Second check again and let the oil drip on something clean and white like business card or something.
Check the paper towel for discoloration from purple to brown to turning more black. Check the drip for transparency as well.
Using these indicators you can determine when the oil is breaking down and or collecting engine wear. Change when the oil is starting to change from a light brown to a darker brown, but yet still somewhat transparent.
At 5K my oil is still quite transparent and only a slightly darker shade of brown.
If you monitor the oil through its life you will visually learn and see how it changes as the additives are used up and broke down.
To be extra anal about it you can keep the paper towel swipes and write the miles at which it was checked as a future reference and learning tool.
RP depending on use and engine will stay purplish in color for roughly up to 2K miles then will turn to a lightish brown like any oil. From there it will continue to darken depending on wear and driving conditions and use.
Also keep in mind the RP as a synthetic can act as a cleaner for petroleum based oils. So your first oil change may show more signs of darkening sooner on the first fill.
Man this is a lot of detail for such a simple question. Ha