Here are some shots of my HT hooked up to a Shimano Nexus 3-speed through a SBP jackshaft. It's controlled with a vintage frame mounted indexed shifter. I started out with a Huasheng 4-stroker that pooped out on me after 4 yeas of riding. Had the HT sitting on a shelf and decided for something different. Had to remove mounting plate and adapt jackshaft mount to work with the rear mount of the 66cc HT, but it works great. The Shimano hub is pretty strong, but it doesn't have sealed bearings. If you ride in water the bearings will rust and she fails. Internals are cheap to replace, about $100. I like the extra power of the larger engine and its fun to shift through the gears. It's easy to change gearing. I have one secondary drive gear for road use and another for trail riding. The 3-speed comes with a coaster brake setup or a disc brakes. I recommend the disc setup with Avid BB7 MTB calipers and 220 mm discs. I can smoke my tires with a dual brake lever to allow for a clutch lever on the left handlebar. Some will say this is no longer a MB, but a small motorcycle. I don't care what you call it, it's fun as heck to ride. StevenMain has a good point about close ratios, but I have plenty of low end and top end with this hub. Good luck on your build. Remember, this is all about fun.