Mountain Biking - Kona Hahannah: What are the most worthwhile improvements?

I have a 2002 Kona Hahannah. I recently retired it from the daily commute. I am thinking the fenders and mirror will be the first to go. Other than that everything is stock right down to the tires. Rather than spending a grand to get a better hard tail I thought I would spend some month on this bike to improve it's off-road worthiness. I am looking to do more recreational cross country biking (4-5 hour outings on rough terrain with 500m to 1000m elevation changes on singletrack). I was thinking some better knobby tires for better grip, replace the drive train (it is worn from commuting all winter) and possibly upgrading the forks (currently SR Suntour).

What do you think?

Well, for the cost of upgrading the fork, drive train and tires, I would have to suggest getting a new bike. Especially if you put it through the rigors of a Canadian salty winter. A new respectable fork will cost you around $300 Canadian, and a new drive train probably around $175. That coupled with the new tires brings you probably somewhere close to $420 for the components you were looking to upgrade.

Perhaps keep this Hahanna as the commuter and buy a new 2005 Hahanna to use on trails? If you do go this route and decide on an alternate bike, search around the forums for advice on buying a new bike as the selection has probably changed slightly since 2002.

Thanks, Swifferman.