sprocket change? no, thank you....
After reading some of the suggestions here, I went ahead and replaced my front sprocket from the stock 15T to 16T, thinking it would do wonders for my bike. The result? My 2001 DR200SE instantly turned sluggish, acceleration was awful, and my milage dropped from 95mpg to the low 70's. On even the smallest uphill incline, I had to drop into fourth, and could rarely get it out of there without almost opening the throttle to its max. What's more, it performed awful in the dirt --had to slip first gear to get rolling in some cases, and overall it just handled like a pig. Ugh.
After a few days of this, I could tolerate it no longer. I put the original 15T back on, and she is running fine again. My mpg is back in the low 90's again, the bike is responsive, and I can ride it on dirt roads with no problems.
I mention this only because people should be aware that this mod may not be everyone's cup of tea. For the record, I am and 5'8" and 210+ lbs, so lighter folks may have had better luck with this than I did. But the truth is that the DR200SE just doesn't have enough juice to pull these higher gear ratios. This engine is most effective with higher rev's and lighter gear load. The drop in mpg is proof that the engine is working less efficiently. (And, no, it is not just a matter of increased wind drag due to higher speeds --if I ride near 60mph with the 15T, I still get much better mpg than the same speed with 16T.)
See that 40mph mark at the top of the speedometer? That isn't a coincidence. The engineers put it at the 12-o'clock position because that is where the bike is running at optimum efficiency. That's how I get 90+ mpg. If you want to cruise the highways at 70+mph all day long, then this bike is probably not the best for your needs. I bought a DR200SE because I wanted a lightweight dual-sport to explore nearby dirt roads, maybe do some weekend trips with, or even try a segment of the Trans-America trail. It's low seat height fits my inseam perfectly, and I end up doing more daring things with in on the trails than I do with my KLR 650. The DR200SE is a great little bike: it is relatively cheap, uses almost no gas, and is tremendous fun; but one has to understand its purpose and design limitations. It is a 200cc-class engine, and in my case, the 16T/45T combo (or the similar 15T/42T set-up) did not work for how I use the bike.
I'm not saying you shouldn't do it, but I just want to point out that messing with the stock gear rations may not always be such a great thing. No doubt several folks have done it and are quite happy, and kudos to them --I don't want to deny them their joy. Keep in mind, however, that this mod may not be for everybody and people should understand the unintended consequences. I wish someone would have mentioned that before I spent the time and $$$ on this experiment... (or maybe they did, but I missed it in the 400+ pages of comments...) In any case, I hope this information helps others avoid a similar mistake.
By the way, there have been several complaints about the DR200SE experiencing heavy vibration and buzziness at higher speeds (and hence, is one of the often-stated reasons for doing the sprocket mod in the first place). May I suggest that part of the culprit is the knobby OEM tires and their lack of proper balancing? I would like to report that after replacing the stock tires with Shinko 244's and putting Ride-On in the tubes to act as a sealant and a dynamic balancer, the vibrations are nearly gone. This bike rides smoother than my KLR (which has very good counter-balancers, and is fitted with the more street-oriented Shinko 705's, I might add.) Something to think about...
Cheers, and happy riding!