Yamaha Zuma 50 vs 125

[kYLEMtnCRUZr]

Hello everyone. I am looking at the Zuma line. 50cc vs 125cc

Fuelly shows similar best MPGs for both bikes. Yamaha claims 132mpg and 89mpg for 50 and 125, Yet people seem to hit between 100-120 no matter which they own. Is this because there are so few hardcore hypermilers using fuelly? (since hardly any leave any notes worth anything. once in a while you can tell a hardcore, disciplined-with-the-throttle-position rider from the mpg and notes)

Basically, if I bought using Yamaha's MPG figures, I would lean towards the 50cc. And if I bought using Fuelly's MPG figures I would get the 125cc. Who do you think is more credible here?

Still want a Grom. But not for $3500 used and 25cc shy of freeway legal HONDA! GRRR.

Whatever I get, I would like to have a recumbent bicycle windsheild up front with some ghetto coroplast tail section/sides.

Grom is the obvious candidate for a mini streamliner, but these Zumas are floating around in the $1500-2000 range and that works best for me now.

Thanks for the advice!

-Kyle

[cRiPpLe_rOoStEr]

The 125 having a little more usable low-end torque than a 50 might allow you to ride it more efficiently, at lower RPMs and the engine works a little lighter. Those 50cc models are still made just because in some countries their riders are exempt from a driver license.

[sendler]

I wouldn't want a top speed of 40 mph.

[kYLEMtnCRUZr]

I hear ya there, but a lot of roads around here are 35mph. Of course 125 is ideal but with 43mpg to be had, I just had to ask.

I know Craig Vetter had mentioned the sweet spot being 125-175cc and that even the dimensions of the piston and surface area play a big part in efficiency. Just can't find any specifics. Maybe that info is reserved for his book. But then there are some college classes building hyper milling vehicles using 50cc engines so who knows.

Craig's focus from what I've seen is 65mph. If its under that then he does not care from what I have noticed. That's fine for most people, but I have little straight shot freeway commuting to do. If Craig lived on a small island of 35mph roads, perhaps his sweet spot would be 50-125cc?

[Grant-53]

Any vehicle will benefit from streamlining. The local Yamaha dealer's wife rides a 125cc and loves it. We are in a fairly hilly area. The routes you take will determine mpg as much as anything. Look at bicycle routes on the map apps. If you need more speed there are many parts to hot rod the 50cc. The most important engine efficiency feature is compression ratio. Come spring I will likely start work on a 50 cc Honda scooter for my son. In town 40 mph is fast enough.

[gil]

In my view a 50cc bike is useless, i own a Honda Metropolitan and its super slow. If i would definitely choose the 125cc scooter or motorcycle. The Zuma 125 and the Grom 125 are priced about the same, although getting a Grom at MSRP is difficult but not impossible. Zuma has a CVT transmission, great for the city and easy to ride, the downside its difficult to modify the final gear ratio, not impossible but expensive, and unable to use lower gear ratios when attacking hills. The Grom has 4 gears to choose from, changing the final gear ration is easy, as it only requires new sprockets and a hour of work.

The Grom top speed is 65mph with stock final gear ratio, its drag limited.
A friend of my owns one, he loves it, he has even gone to LA area and back, he lives in the county of Santa Cruz in California. He has a fuel log here, his bikes name is Morg. I also believe the Grom has the same engine as the one used in the European Velomobile that attains 217mpg, it uses the Honda Innova 125i scooter.


http://ecomodder.com/forum/showthrea...diy-11970.html

Gil

[cRiPpLe_rOoStEr]

Originally Posted by gil

In my view a 50cc bike is useless

If the 2-stroke 50cc bikes weren't tuned so restrictively I wouldn't mind having one.

[gil]

Originally Posted by cRiPpLe_rOoStEr

If the 2-stroke 50cc bikes weren't tuned so restrictively I wouldn't mind having one.

That's a good point, the Aprilia SR50 comes to mind.


Gil

[cRiPpLe_rOoStEr]

Originally Posted by gil

That's a good point, the Aprilia SR50 comes to mind.

There was also the RS50, shaped like a real motorcycle instead of a scooter. When I was 11-year old the RS50 was on my wish-list...

[Grant-53]

The new Zuma 50 is a 4 stroke. I saw an RS50 on e-bay without title so I don't know if it could be registered. See motoIQ.com on their project scooters.