Go 3 speed!
I've got an old Stumpjumper that is converted to SS for townie use with a milk crate attached to the rack. Great as general commuter/grocery runner. I run it kind of low gearing though (38X16). I keep meaning to put a 42 ring on it, but I'm fundamentally lazy.
On my old Cannondale hardtail, I recently removed the rear cassette and shifter, but kept the front three rings with derailleur and shifter for a 3-speed conversion. I think it rocks! I've got a medium gear for general use (32X15) and a big gear for once I'm up to cruising speed (42X15). I haven't really needed the granny, but it's there for the occasional steep hill.
On both bikes I use the original rear derailleur for chain tension. Definitely need it on the three speed, but I couldn't find the "magic" gear combo to take enough slack out of the chain on the Stumpjumper. I used a Surly Singleator for a couple of years on the Stumpy and it worked fine, but I had to keep an eye on it as it would get loose and then the spring finally crapped out on me. I'm not into aesthetics nor weight watching, so the derailleur works fine for me.
As far as the hub, no need to go get a new hub and build up another wheel, your Shimano compatible free hub will work, you'll just need some spacers. I used some old cassettes and drilled out the rivets to get at the spacers (not all cassettes are built this way). Then you'll need to line up the chain. I used a BMX cog and chainring with a wider chain on the Stumpy, but kept the narrow chain with the ramped rings on the Cannondale.
I've got an old Stumpjumper that is converted to SS for townie use with a milk crate attached to the rack. Great as general commuter/grocery runner. I run it kind of low gearing though (38X16). I keep meaning to put a 42 ring on it, but I'm fundamentally lazy.
On my old Cannondale hardtail, I recently removed the rear cassette and shifter, but kept the front three rings with derailleur and shifter for a 3-speed conversion. I think it rocks! I've got a medium gear for general use (32X15) and a big gear for once I'm up to cruising speed (42X15). I haven't really needed the granny, but it's there for the occasional steep hill.
On both bikes I use the original rear derailleur for chain tension. Definitely need it on the three speed, but I couldn't find the "magic" gear combo to take enough slack out of the chain on the Stumpjumper. I used a Surly Singleator for a couple of years on the Stumpy and it worked fine, but I had to keep an eye on it as it would get loose and then the spring finally crapped out on me. I'm not into aesthetics nor weight watching, so the derailleur works fine for me.
As far as the hub, no need to go get a new hub and build up another wheel, your Shimano compatible free hub will work, you'll just need some spacers. I used some old cassettes and drilled out the rivets to get at the spacers (not all cassettes are built this way). Then you'll need to line up the chain. I used a BMX cog and chainring with a wider chain on the Stumpy, but kept the narrow chain with the ramped rings on the Cannondale.