The frame is a bent tube, which flexes. The wheels are usually around 10 inches outer diameter, usually with 3 inch thick tires to deal with bumps rather than the normally 1-2 inch of vertical suspension travel, which where I live is about half what they need. We have 4 inch deep potholes, tar snakes, and bigger wheels could save your life because they won't stumble in the hole. The other big problem here is that the engine is mounted to the frame on a pivot, and its weight is also the swing-arm for the rear wheel. So what? It adds to the rear wheel's weight, which means when it goes up it has to overcome the inertia, and when it goes down, the same problem. This wrecks its handling on rough roads, which where I live is ALL OF THEM. Despite this, people still buy scooters, and in Nevada City or downtown Grass Valley they make sense since these towns both pre-date cars and streets are narrow enough to spit across. Many houses were originally miner's cabins and have no garage, and most of the carriage houses got turned into more houses rather than a garage. Yes, they had carriages and wagons and buggies here. Mine carts too. The advantages of the scooter is its around 100 mpg and only costs around $150 in parts to make. Maintenance on a 2-stroke engine is around every couple thousand miles, or less, and requires changing the flapper valve, similar to a chainsaw, and cleaning the evil burnt oil out the combustion chamber and possibly the piston and rings if it has them, as well as the belt, pulley-weights, and bearings of the transmission. The whole process is around 45 minutes of work, which is not much.
Honda Wave 125cc EFI. Successor to the SuperCub |
Why does it have to be such a stupid mess? How do you fix it? Well, a frame can be changed to be more rigid, with a longer base so the engine is firmly mounted and removed from the trailing arm of the suspension. This will drastically improve the ride and safety of the bike. The drive chain goes to a transfer cog, possibly with a belt drive like a motorcycle, itself on a pivot in line with the axis point of the trailing arm, which reduces complexity. This is such a no-brainer fix I am baffled why this isn't an industry standard. Another one is the transmission should have a type of mechanical lockout so you can use the engine as a brake going down steep hills.
Bigger wheels exist, and you can still have them and retain the looks of a scooter by scaling up the tires and suspension to deal with non-fantasy roads with real potholes and problems like the real world has. The frame flex is best fixed with a low profile box frame and retain the flat floor with the grocery bag net/hook, which all riders agree is one of their great features. I'm kind of surprised there's no open-source project for these.
As for the pollution, there IS a solution. First, direct oil injection, and fuel injection in a 2-stroke engine avoids all the smoke. You don't have to premix the fuel and 2-stroke oil. They go in separate reservoirs. You also avoid the engine blowback into the crankcase, which is what makes it so dirty and damages the bearings till the engine destroys itself. This is not a problem we need to keep having. Switch to the mastervalve setup on the muffler, which racing 2-strokes do, or just upgrade to a 125cc 4-stroke with EFI, preferably one that's programmable or multimode so you can test a new one without losing your existing one.
From what I have seen, the above solutions would fix most of what is wrong with a scooter, beyond the rider herself/himself. A scooter that doesn't try to kill you and starts every time, that's a vehicle which a really progressive California should have be in favor of, and would have cost less to give to every single person in the country than the money already wasted on the bullet train to nowhere. If California had good government this wouldn't be an issue. But we have terrible government so solutions are illegal.