Is it advisable? My wheel builder always recommends using a 'nice new rim' . Is it a hassle or is it just his thing?
It's fine. I've rebuilt wheels using old rims on new hubs when required.
Cheers C. That was the plan. Except i wasn't going to do the building.
If the rims are still attached to a wheel, make sure they are removed with a bit of care. Randomly cutting through spokes can cause the rim to buckle. Better to unwind spokes gradually - one turn at a time - starting at opposite sides.
Rebuilt plenty of wheels using old rims, spokes & hubs.
Old rims are fine as long as you're not fussy on it being 100% straight. Obviously if the rim has dents in its going to be nigh on impossible to get it perfectly true. That's prob why the bike shop guys doesn't like doing it.
New spokes are worthwhile though in my limited experience. I found it much easier to do a good job with new ones over recycled.
"[i][s]Old[/s] slightly damaged rims are fine as long as you're not fussy on it being 100% straight.[/i]"
FTFY. "Old" does not automatically mean there's anything wrong with them. If they're not damaged, there's absolutely nothing wrong with re-using old rims.
Shops would rather sell you new ones though, obvs.