The pinions will pretty much last for years when used against plastic spurs, especially hardend ones- aluminium pinions will wear don faster but still last a long time ( seen a few pics, they end up with teeth that look like a circular saw blade!
)
Generally speaking 99% of spurs are made form nylon, pretty tough material that doesnt wear down too quickly unless you set a realy bad mesh or you land on-throttle ( usually chip a few teeth off doing that once too often ). I've ran the same spurs for dozens of sessions and only ever damaged them from a melted slipper or bent motor mount (whole motor swung towards the spur and the pinion ate the teeth off it- 30mph crash into concrete steps will do that...
).
You may get lucky and find some delrin spur gears from somewhere like integy or gpm ( actually one of the few good parts they make ), but otherwise the stock spurs will* be fine.
*more than likely anyway...
