Re: Sachs 505/1 increasing gas mileage

Gordon Babbitt Wrote:


> Today, my stock '78 Columbia Commuter achieved

> between 137 and 146mpg when covering about 33

> miles of very rolling terrain including 10 hills

> requiring pedaling up. Twenty-nine ounces of fuel

> consumed for the estimated distance of 31 to 33

> miles.

> The two-speed automatic sure slips on the hills

> compared to my old '60's Sachs 2-speed standard

> shift in Switzerland.

Commuters with Sachs engines come with a 1 speed transmission not 2. There is a 2 speed option but its a manual with a hand shifter. Unless you have a Solo Commuter with the coveted 2 speed pulley.

Re: Sachs 505/1 increasing gas mileage

Gordon Babbitt /

]> prawny 1 Wrote:

> -------------------------------------------------------

> you would probably save more weight going to fully welded bmx 20" rims,

> the smaller diameter will have less effect on gearing than the 24" rims

> at the cost of stability.


> some 2.125 or 2.25 bmx tyres will be lighter than the moped equivalent

> (16" dot tyres)


> If fuel economy is your main concern you might be better off with a

> motorised bicycle,

My main point was the challenge to increase performance, i.e. fuel economy, of the Commuter moped which has proven itself since posting 7 years ago. For those interested, the MTB 24" rims increased wheel circumference slightly and have held up superbly for >1,000 miles; I suspect full suspension has forgiven the effects of the harsh roads on the rims to some degree. The narrower tires/tread has held up well to cruising with no cornering concerns.


Have since obtained a 1978 DEMM Smiley and plan to switch out its stock 16" moped rims for 20" aluminum BMX rims (36 hole). Overall circumference will drop slightly but fuel economy should increase.

Re: Sachs 505/1 increasing gas mileage

So in 7 years you rode 1000 on the same tires and spent $30 in gas.

Re: Sachs 505/1 increasing gas mileage

classic carl jepsen /

I never post on these kinds of threads, because they are TOTALLY subjective.

In my OPINION... let's call a spade a spade here. I mean really, when it comes down to it, people don't buy mopeds because they want to go over the speed limit. WAY over the speed limit.

I mean seriously, you absolutely CANNOT ride a moped on the highway. You may not be happy about it, but even the POS honda ruckus can get up to legal speeds faster than 90% of the mopeds on the road. And you can cruise at 20 mph all day long on that little POS. Now, I would agree you want better passing power IF you will be riding on the highway. But mopeds make about 3 HP and about 3 ft lbs torque. The a kit doubles the HP, and adds more than 1ft lbs of torque.

People buy mopeds because A) It's way more than you need to get over the legal limit C) Still gets to 20 MPH D) Still has less tendency to get you into trouble

Re: Sachs 505/1 increasing gas mileage

Probably Fred /

> pat splat Wrote:

> -------------------------------------------------------

> So in 7 years you rode 1000 on the same tires and spent $30 in gas.

So a maybe 3-4 weeks worth of research accomplished in seven years!

You should get a job at a college doing research and having findings like collage kids eat when they’re hungry (True story million dollar research).

Today I went to the store and rode for around an hour afterwords so like 30ish mi of use,

I’m not sure of the mpg of my 40 mph Tomos but other then a pipe and up gear it’s mostly stock

To ride 1000 miles in seven years, I can’t comprehend how little that is per day!

Is that like going to the end of the driveway and back once a day or what?

Re: Sachs 505/1 increasing gas mileage

Gordon Babbitt /

Yeah, I was dependent on a moped in the late '70's for getting around Switzerland and Germany as a young adult. Now, a generation later after retiring from an R&D job, riding a moped 5 - 20 miles brings back pleasant memories, which I'm sure most of you will have. The Columbia sits much of the time since there are more appropriate vehicles around to meet family needs. Can't part with a fun economical machine requiring no annual insurance, and only a onetime $19 registration fee. The M1 has been a given for over 40 years for the CB400F and CB550F.

Some have ideas and others have actually done the work. Maybe someone else will break 200mpg with a decent ride and share how they did it in the name of performance.

Re: Sachs 505/1 increasing gas mileage

Cool Westy, i think the relatively light velosolex was advertised at 200mpg, not comfy but very economical.

My turn to Carl...

My gripe with the electric, hybrid green environment anti carbon thing is its hypocrisy, face it, it takes energy to make energy. Majority of power comes from hydrocarbons/radiation to produce electricity. There's even the added energy to properly dispose of batteries. Lets not forget energy it takes to make money, lots of it, the 40k to 100k takes energy, etc. So, i would like to see a wholistic approach to the Global warming problem, one that includes the energy of production, labor, and costs to the environment into the equation.

Totally irrelevant to your fuel economy goals, but my realistic question to you is how much did you spend sourcing new rims tires tubes, gears,etc whilest the old ones were useable. So at what mileage point due to the increased fuel efficiency offset the added costs of time, money, production and disposal. Riding 1k in miles isn't gonna gonna cover it, has to be more like 20k. My point is if you just kept your old rusty rims, tires and sprocket it would be much more economical and beneficial to the environment.

Isn't it strange that when you were a kid riding the same moped that it was economical enough that you didnt really worry about wasting money on gas and just riding? I think this is the true spirit and original intention of the manufacturers at that time. Dont get me wrong i like that you have documented your findings over time and have stuck to the same post for continuity, very important! I do find it interesting your attempts at increase fuel efficiency kinda the total opposite of what everyone else is trying to accomplish, funny.

Re: Sachs 505/1 increasing gas mileage

Pretty neat, I'm still a little sketched out by the tire choice, i wore through some bicycle tires in a few months and have never tried again. Definitely higher inflation and lower tread should improve mileage, better bearings throughout, anything to reduce friction. I love ceramic bearings being a ceramic engineer, tho cost benefit is probably not there and the availability might be tough

Keeping everything clean and tuned though, i'm still impressed to see over 150mpg. I remember getting almost 200 on a honda cub but that's a small 4 stroke with multple gears.

I wonder if you could see even more benefits if you did the math trying to match timing, pipe, carb and intake lengths etc to maximize efficiency. Could a tuned pipe prevent lost energy in the

Also interested how much the external lighting helps - 35 or 70 watt total lighting would be way on the high end, and it's like 800w/1hp but it's gotta save even a little not running the lights off gas also.

More math!

cool stuff

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