[Lewis82]

Recently had some work done on my bike. At ~35k miles and having owned it 2years I had the fork oil and seals changed. Asked the mechanic if he noticed anything non-standard about the springs. He mentioned some scoring on the tube which he sanded down and isn't concerned about and a previous owner (1of 5 or 6) added some shims. Any ideas as to why they'd be added? What would be the next step to upgrade for street use? It has a nitro r1 rear shock but nothing up front so will look at changing those.....later down the line.
Tia