My 2013 B5 (carbureted with an aftermarket pipe) feels overstressed at much over 55-60 mph. While I'm sure it could go faster, and could be made a little faster yet, I'm a bit wary of running that antique design long stroke made in India too fast. A modern 500 single would keep up with traffic easily, but they are all short stroke, made out of better materials, and have much better build quality. When I need to go fast, I have a Kawasaki Vulcan 750 and a H-D Sportster 1200, both of which will easily top 100 mph with room to spare. I ride the Enfield for recreation only, because it is so much fun to ride. I also only have a 6 month riding season, but because of extreme heat, not cold. I have a safe place to keep it during that time, and start it up and warm it up at lest twice a week. Sometimes in the summer I will get up before sunup and take it for a short ride. There is no way it would keep up on our urban freeways, but we have a lot of slower secondary roads it can be ridden safely on. We also have a lot of speeders. When I see someone coming up behind me, I move to the right to let them by. Especially since putting the carburetor and pipe on it, I have developed an emotional relationship with it and don't want to give it up. For me, the Enfield is what it is, and I'm happy thumping along at 55 mph. Even my 234cc Honda Rebel will outrun it, I've had it at a GPS 80 mph for short periods before. Despite the small engine, it is a short stroke twin using late '70s Japanese technology, so it is built like an anvil. You can ride it at full throttle for a very long time without harming it. If the Enfield is your only transportation, and won't do the job, you may have to replace it with something else. Maybe one of the new twins?