I'm planning to set the rider sag on my new 848 but the preload nuts in the shock are not easy to get at with a C spanner and I'm not really prepared to go at it with a drift. Am I better of fitting an adjustable ride height linkage and leaving the shock alone? It may well be the case that even when I achieve the factory settings I want to sharpen the steering more.
Ride height and sag are two different things. If your sag is wrong adjusting the ride height won't help.
As above, get the right tools for preload (local Ducati dealer can help) and imho worth the money to get height adj bar too
Once you have taken loads of preload out the rear shock the bike will be a significant amount lower at the rear and will handle differently as a result. The adjuster will allow you to gain back the lost ride height but maintain the correct preload. Even a few mm at the shock makes a big diference to the ride height.
