Moped thoughts wanted

[FXSTi]

I'm in the thinking stage right now, but would like some input from you guys on whether this might be worth pursuing.

I have been thinking about getting a hold of a scooter style 50cc moped. My plan for it would be to stretch the bottom of the frame (where your feet go), and making that the place to put my butt. From the little bit of looking I have done it looks like the fork neck has a built in riser which could be cut down. this seating position would require an additional neck with a rod from the new handlebars to the neck for steering.

In looking at the 214 mpg Honda on the homepage, I think an aero body could be built, making a MPG monster.

Potential problems might include having such a long wheelbase (wide turning radius) and being so low that traffic might not see me well.

Here in Michigan, under 50cc and auto trans is a moped which requires no insurance, has cheap registration, and speed limited to 30 mph.

So, what are your thoughts? Is this worth pursuing?

Edit: Adding a horrible picture using paint to show sort of what I am thinking. The red area would be the front of a bicycle to move the steering closer to the rider and would control the steering via a tierod.

[Sven7]

You're talking about a Ruckus rated at 114mpg?

I've thought extensively about the same project. One of the problems is, when it legally tops out at 30mph and is rated for ~100mpg is it really worth trying to pursue aero?

Perhaps a custom frame like the one you posted could get you into a "kit" category and allow you to legally reach highway speeds. Looks like it's a single speed too. If you could get even two speeds and maintain 50-55mph it would be really great. I would recommend looking into some engine mods to get more power, and possibly a larger drive wheel. Lots of people mod old mopeds to get a few more hp, and with aero you could really use them properly.

LOTS of LED tail lights on the rear end could help the visibility issue. I'd put a little lighted fin right behind the headrest like the ones they have for cameras on F1 cars.

[FXSTi]

I've looked at the Ruckus but I'm thinking more like a cheap Chinese scooter as a test bed.

The tempting one might be the new Yamaha Zuma 50f. It looks like the old Zuma but has fuel injection and water cooling. Yamaha has rated it at 138 mpg. From some scooter forums it looks like people are seeing low 40 mph out of the box.

Even running 40-45 mph aero should be a big help. Look at the guys with the velomobiles.

[baldlobo]

not trying to be a wet blanket, but you might want to see if there is a minimum seat height requirement. up here in manitoba we have a minimum seat height of 26 inches.

[Tango Charlie]

I am not a fan of mopeds. Aside from the fact that they are often driven by inexperienced and unlicensed drivers that are not aware of traffic laws, they are slow enough that they impede traffic flow, and yet they are fast enough that it is quite difficult to judge overtaking them.
My first gripe is not a concern in this context, of course. But in my opinion I think it would be dangerous to operate a low slung vehicle that cannot keep up with traffic.

If you can make the thing accelerate half way decent, and top out at 55 or 60 mph, then you got something.

Again, the Europeans have the advantage with much better vehicle options to choose from.

[Ryland]

For sure check seat height law and handle bar height laws, some states also have laws preventing recumbent seating.
Personally I wouldn't do it because it's an unstable seating position when you only have two wheels, being able to swerve quickly around people who are pulling out in front of you is a huge advantage and will save your life.

I also don't see a scooter like that getting all that much better gas mileage because of streamlining, you are limited to 30mph by law and if you look odd the cops are going to keep a closer eye on you and your speed, so at that point if streamlining does have an affect then you need to change the gearing so the little 50cc engine is no longer turning as fast, otherwise I don't see the gallons per hour of fuel being used changing much.

If you do this, my suggestion would be to turn it in to a tadpole trike and use larger light weight moped wheels in the front so you have less rolling resistance and more stability, I'd also want to run a multispeed gear or chain drive like the Tomos mopeds have and avoid the CVT belt drives, maybe even get one of the fuel injection retrofit kits if you can't find an engine you like that is fuel injected.

[jtbo]

Wind, when you have strong wind from opposite direction, how are you feeling when riding a bicycle?

Drive car 20mph and push out ping pong paddle from window, what do you feel?

Moped with small tires has next to nothing rolling resistance, same with bicycles, velomobiles etc. So there it is bit different than with cars which has weight alone causing more rolling resistance (more tire deformation).

Keeping weight small as possible would be needed for this kind of project. Better aero would allow increased gearing, bigger rear tire, but one would need to find out way to make it not go any faster, lowering rpm limiter might work.

For city traffic 30mph would be plenty, speed limit at least in here is less in city areas. With some clever tweaking one might get also changes to how ratios are chosen and maybe more control over the clutch, so that some P&G would be possible.

But how do you keep from tipping over at traffic lights? 3 wheels?

[johnunit]

I agree with some of the criticism already brought up.


To me, a recumbent position like that is ONLY safe/practical if you're capable of driving in less than very inner-city traffic, which around here 30mph would not get you. Basically I think you'd have to make it something that did require motorcycle licensing and insurance for it to make sense. That said, an ultra-lightweight trike or powered recumbent that got 150 (let's say) mpg and could hold a reasonable amount of baggage may be worth your while even with insurance and licensing, depending on how much you can use it and what insurance costs in your area. For a small-town delivery person or something it might make a lot of sense. Regardless, I think it's an interesting technical excercise and I admire your thinking outside the box.