The standard guideline is to never gain more than 1 lbs a week. Any more than that and you're gaining fat like crazy which isn't conducive to lean mass gains in the long run. I hardly ever bulk, although I'm experimenting with it right now, so I don't have any recommendations on duration there. As for cutting, I tend to give myself plenty of time. 8 weeks is a minimum really if you're looking to keep as much lean mass as possible.
How many pounds and how long are you bulking/cutting cycles?
Im on a continuous bulk, bulking 4 years now never cut for more than 4 week at a time havent had to yet, of course stressful situations have come up where i have lost up to a stone in a few weeks so I suppose thats crash cutting though much more of a hinderance. Up 73 pounds now from when I started
__________________ If the end justifies the means....