Not sure what you are asking?
Is a springer front end safe? Or is your springer front end built right and safe?
Myself I would not run an extended springer.
A guy I used to know (notice I said used to know) had his come apart on him and the wheel fell off launching him into a telephone pole.
He was wearing one of them belts around his waist made from a primary chain that was popular back in the 70's and the EMT's said that it was the only thing that kept his guts from from spilling out.
Not a pretty picture.