Hi, Here is some info on a suspension upgrade on my 883 Iron. I have just fitted a pair of standard Progressive fork springs, the ride is a lot less jarring and at speeds above 65 mph that skittish feeling has gone. If you own an 883 Iron I would recommend this upgrade. Drain your fork oil, Jack the front end up to take all the weight off, forks fully extended. Remove original springs and spacers. Drop in new Progressive springs first then add 10 weight fork oil until the level is 165mm to the top of the forks. I measured it using a thin steel rule. Now drop in 3 inch spacers, Progressive supply plastic spacers but I did not like the look of them so I turned up some aluminium ones at work, same O.D but with 4mm wall thickness. I should mention that I have also have 13 inch Progressive rear shocks. It feels like a different bike!