Im putting a custom rear fender on my 2005 nighttrain. I want the fender to ride as close to the tire as possible but obviously i dont want the tire to hit the fender when i go over bumps or have someone on the back. My question is how much room to i need to leave betweent the tire and fender? I thought about lowering the bike 2" and then mounting the fender like stock but if i can leave the bike the stock height and just lower the fender i wont have to give up ride comfort. Thanks for your help!