[quote=PeteSC;38126]I just bought an '03 DR650, and am going throught the same 'mod' process....
(Actually just getting started!)
A couple of good message boards are MaximumSuzuki.com, and ThumperTalk.com
It seems the hot set up is to drop to a 14 tooth sprocket on front. It does take a little modification with a grinder!
(Haven't done it yet)
Dual Star - The original Motorcycle Adventure Outfitters™ has some DR650 stuff, including some suspension upgrades.
Kouba Link has upgraded springs for the rear shock.
Kouba Link
Racetech does also.....front and rear.

I agree the 15 tooth is too tall in first gear, and the 14 tooth makes everything about the bike much better below 80mph cruising speed (you can still make it over 100mph with the 14 tooth) but the vibration from the higher rpms make your arms get tired faster... but nothing major on 100 mile length trips.

I personally like that much better for the shorter trips with the 14 tooth.
Since I ride 80 miles down the highway often i put the 15 tooth back on and unless im going to do a lot of tight stuff found that the torque it has will still easily pull hard enough to break traction on the dirt even lugging the motor in third gear on the fire roads going up cajon lots of fun

The sprocket change can easily be done from 14 to 15 or 15 to 14 in about 10 minutes and only have to adjust the chain no mods necessary on my 06 model dr650

The biggest drawback other than the added vibration over 80 mph due to rpms being higher is that with the 14 tooth the chain will wear the slider guide on the swingarm out quicker since it is a lot closer to it all of the time so it contacts it more often.
I think the perfect blend would be if you had a 44 rear and a 15 front since that would still be a higher ratio than 14/42 and lower than 15/42 not sure if they make the 44 tooth rear though