Yeah, with longer rear shocks you definitely need to check belt tension. With the lowered Harleys, like my 48 and unlike most bikes, due to the swingarm angle the belt tension is actually at its tightest with the suspension at full extension and loosens during suspension compression. On most bikes, and like the one pictured above (and my Buell below), the swingarm is on a downward angle. As it moves up during suspension compression, the axle actually moves father from the output shaft/front sprocket/pulley (tightening the chain/belt) as it reaches a straight line connecting the axle, swingarm pivot and output shaft, then loosening again as it moves up beyond that point. The quickest way to destroy the output shaft bearings is to run the belt too tight. In fact, it's generally known in the Buell world that the factory belt tension spec is too tight. Many people have had issues after letting the dealer set it to their spec and the recommended tension is to run it quite a bit more loose. Here's a pic of my S1 with a line drawn in to illustrate the point of max belt tension as the suspension moves through its arc of motion: And a gratuitous shot of the bike: But, from what I understand, there isn't an issue with belt interference until you get over 13.5" on the Sportsters. Still like to get that number confirmed as the upper limit though. I fully intend to get the longer jiffy stand from the Roadster once I lengthen the forks and shocks so it will have the proper lean angle when parked up on the stand, though. I'm not sure what would happen with a longer shock and lowering blocks though. It could allow for a longer stroke shock and work out fine... Then again, the leverage ratios would be different so it could screw up the spring and damping rates. I'd prefer to stick with the stock mounting points and just get the correct shock sprung and valved for my weight and riding style.