Langster upgrades

So I have started to ride my Specialized Langster with a new 15-teeth cog from A.C. Racing, I do confirm, it hurts more than the 16-teeth freewheel that I was using earlier. Good thing is, on this Langster hub, since it's a dual hub, I just installed the new freewheel on the other side of the hub, and will be able to flip the wheel to go from 15 to 16 enad vis & versa! How nice!.. Since 15-teeth is quite smaller than 16, the chain is a bit too long, but pulling the rear wheel back one centimeter in its horizontal drops did the trick. So now I am riding a 15-teeth freewheel. Fast on flat, a tad more thighs consuming. Did not really take a chance with any hill so far, since I got injured skiing about three weeks ago, and can't push/pull from one knee at all, following my doctor's order. I tried one freeway overpass and that was too hard. But we'll see once totally recovered. I am hesitating to add a fixie to this Langster. I don't know why yet, it kind of scares me still, although the hilarious and quasi-religious experience described by many is very attractive. Maybe a question of months. Besides, I modified my Langster with a new old handlebar, removing the old original drops and putting a riser instead. Looks quite retro with its original black paint. Sweet townie. Besides, I really enjoy the Continental Gator Skins, which I have also set on my Fuji road bike.