Mini-engine positioning on bicycle ?

<[email hidden]> wrote in message
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Quoted message said:

With the new petroleum price it's time to re-examine the 60's
bicycle add-on engines ?

Very few of them then drove the existing chain.
Now with the well developed 'multispeed gearing', it seems
obvious that the engine should use this existing mechanism.

The extra forces to be handled should not exceed 50% of a
strong rider, to be able to use existing/stock machines.
This gives a very small engine.

Where would you mount it ?
Could it drive a 'wheel' on the opposite side to the existing
chain crank. Or directly to the existing chain ?

It would have to be clutched and probably geared down.
Perhaps a belt-drive to do both ?

I wish I had access to one of those 3D CAD facilities.

Ideas/criticism ?

Thanks,

== Chris Glur.

Well they have a lot of those for sale on ebay. Unfortunately they require a
good mechanical skill set to install and get working. Plus some of those
kits are plain junk too.
But, over the years since the 60's, these gas powered bicycles are
discouraged a lot by the government now. Most all the states treat any gas
engine powered bicycle as a real motor vehicle now, so you need to title,
register, get insurance and have a driver's license as well to operate them
on a road. You might have better luck with the electric motor and battery
kits they sell though. The governments now tend to encourage those types of
vehicles. Many states let you ride a electirc bicycle or scooter on the low
speed limit roads wihtout having to title, register them or needing a
driver's license even.
Unfortunately some of those kits may still be tricky to install. But the
kits with the motor (motor in the hub) installed in the front wheel would be
the best one of the bunch to setup and use.

But what is best though, is to get a good bicycle and just start riding it a
lot, you'll get stronger over a period of time, and eventually you will not
want to power it with anything except your own legs.

I'd advise going electric... much simpler, and less air and noise
pollution. Getting a prebuilt scooter is probably the best option.

Why reinvent the wheel? There are millions of bikes with engines in use
in China. You can buy them in the US from a bunch of sources on the
internet. Here are just a few.

http://thatsdacs.com
http://www.livefastmotors.com
http://kingsmotorbikes.com

I ride one every day and they work great.

Q

Quoted message said:

With the new petroleum price it's time to re-examine the 60's
bicycle add-on engines ?

Very few of them then drove the existing chain.
Now with the well developed 'multispeed gearing', it seems
obvious that the engine should use this existing mechanism.

The extra forces to be handled should not exceed 50% of a
strong rider, to be able to use existing/stock machines.
This gives a very small engine.

Where would you mount it ?
Could it drive a 'wheel' on the opposite side to the existing
chain crank. Or directly to the existing chain ?

It would have to be clutched and probably geared down.
Perhaps a belt-drive to do both ?

I wish I had access to one of those 3D CAD facilities.

Ideas/criticism ?

Thanks,

== Chris Glur.

Q said:

Why reinvent the wheel? There are millions of bikes with engines in use
in China.

http://thatsdacs.com
http://www.livefastmotors.com
http://kingsmotorbikes.com

China has horrible air pollution. And if there are millions of these
2-stokes with minimal exhaust system things around it's no wonder.

Please don't get one of these.

Rich

Quoted message said:

With the new petroleum price it's time to re-examine the 60's
bicycle add-on engines ?

Very few of them then drove the existing chain.
Now with the well developed 'multispeed gearing', it seems
obvious that the engine should use this existing mechanism.

No, actually, it's not obvious at all. The prevalent design of
derailleur gearing setup mandates that the cranks must turn when the
system is under power. Any acceptable engine assist system will
include a way to disengage the cranks; this is not presently a feature
of any mainstream (or market-accepted, for that matter) derailleur
gear setup. What's more obvious is that an assist engine should have
a drive system that is as fully disengaged as possible when using
human power, so that the only penalty when pedalling is the extra
weight of the motor and system. I believe this is best accomplished
by the use of a special rear hub equipped with a second freewheeling
sprocket on the left side, permitting the assist engine to drive the
rear wheel independent of and separate from the human-power system.

Other solutions definitely exist; this is just the one that makes the
most sense to me.

Quoted message said:

The extra forces to be handled should not exceed 50% of a
strong rider, to be able to use existing/stock machines.
This gives a very small engine.

Yes.

Quoted message said:

Where would you mount it ?

Aft of, and if possible below, the seat.

Quoted message said:

Could it drive a 'wheel' on the opposite side to the existing
chain crank. Or directly to the existing chain ?

See above. This would require redesigning too many things, when
reworking just one will do the job as well.

Quoted message said:

It would have to be clutched and probably geared down.

Centrifugal clutches are cheap and reliable. Gearing the engine down
is probably best done with a jackshaft.

Quoted message said:

Perhaps a belt-drive to do both ?

You're adding needless energy loss unless you want the belt to be part
of a variable-ratio drive system. Keep the speed and grade-climbing
parameters within a narrow (but still useful) range, and you don't
need it.

I will note, however, that many belt-drive motorized bicycles were
made prior to World War II, and one common approach was to put the
pulley groove on the side of the rear rim, thereby providing a useful
gearing solution with minimal effort. Unfortunately, this requires a
wider rear stay spacing than is used on normal bicycles; a special
frame would be needed in order to employ it.

Quoted message said:

I wish I had access to one of those 3D CAD facilities.

You need more than an idea and a drafting tool to execute such a
design successfully.

Quoted message said:

Ideas/criticism ?

I will simply note that such assist motor systems are already on the
market. If they become too popular and/or too powerful, they will
attract the attention of the regulatory bodies, and we'll probably see
them banned, either temporarily or permanently. This has happened
before; the US state of Florida, for one, banned such assist motors in
the 1960s or '70s. If a bicycle was seen underway via non-rider
power, the rider was subject to being cited for operating an
unlicensed motor vehicle and failure to have the vehicle inspected.
(Later, when insurance was made mandatory for all drivers, failure to
show proof of insurance would have been an additional charge that
could have been levied, but by then the market for assist motors was
completely dead.) It is my understanding that in more recent years,
this ban was relaxed to permit the sale of mopeds, but one should not
underestimate the potential for legislative action to render such
systems useless once again. Here in Texas, the use of pocket bikes
(both gas and battery-powered) by underage riders became enough of a
nuisance that they have slowly been getting banned from on-street use;
in the process, such "alternative transport" devices as the Segway
have been placed in legal limbo since they are usually not excluded
from the bans.

Any effort to promulgate a powered transport device should be
undertaken with due care and attention to keeping the regulatory
bodies from hamstringing the effort before it can get started.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

Q said:

Why reinvent the wheel? There are millions of bikes with engines in use
in China.

Among a population that has *three* commas in its enumerator. That's
not as commonplace as it sounds. Even "tens of millions" would still
make it a niche presence.

Quoted message said:

You can buy them in the US from a bunch of sources on the
internet. Here are just a few.

http://thatsdacs.com
http://www.livefastmotors.com
http://kingsmotorbikes.com

I note that all of those are essentially the same motor setup, and
they all require a 36-spoke rear wheel. The rear sprocket is clamped
to the spokes. I didn't see a provision for accurately centering the
sprocket. Additionally, the engine is a 2-stroke unit; the operation
of those is already banned (for *any* device) in certain parts of the
US due to pollution concerns. While the fuel consumption is small,
the probability is high that these would actually produce more grams
per mile of HC, CO and NOx pollution than a late-model compact car.

All in all, I'm not impressed. Quite the reverse. As an engineer I
once knew said, "If these were munitions, I would recommend that they
be supplied to the enemy in the greatest quantity possible." On the
other hand, I think the makers are on the right track; they mostly
need a cleaner-running engine and a better rear hub setup (and better
mounting system) to make this into a potentially acceptable product.
(In other words, chuck it and start over using the same idea with
better execution.)

I'm sure the Chinese will soon be making and supplying something
cleaner and/or less improvised for their domestic market.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

There are also 4 stroke engine kits made for bicycles by
http://www.bikeengines.com

I built one using their belt system parts and a Honda GX31 4 stroke
engine a few years ago. Worked fine but was lacking in power compared to
the Chinese engines. I still have it hanging in the garage.

Q

Werehatrack said:

Q said:

Why reinvent the wheel? There are millions of bikes with engines in use
in China.

Among a population that has *three* commas in its enumerator. That's
not as commonplace as it sounds. Even "tens of millions" would still
make it a niche presence.

Quoted message said:

You can buy them in the US from a bunch of sources on the
internet. Here are just a few.

http://thatsdacs.com
http://www.livefastmotors.com
http://kingsmotorbikes.com

I note that all of those are essentially the same motor setup, and
they all require a 36-spoke rear wheel. The rear sprocket is clamped
to the spokes. I didn't see a provision for accurately centering the
sprocket. Additionally, the engine is a 2-stroke unit; the operation
of those is already banned (for *any* device) in certain parts of the
US due to pollution concerns. While the fuel consumption is small,
the probability is high that these would actually produce more grams
per mile of HC, CO and NOx pollution than a late-model compact car.

All in all, I'm not impressed. Quite the reverse. As an engineer I
once knew said, "If these were munitions, I would recommend that they
be supplied to the enemy in the greatest quantity possible." On the
other hand, I think the makers are on the right track; they mostly
need a cleaner-running engine and a better rear hub setup (and better
mounting system) to make this into a potentially acceptable product.
(In other words, chuck it and start over using the same idea with
better execution.)

I'm sure the Chinese will soon be making and supplying something
cleaner and/or less improvised for their domestic market.

Earl Bollinger said:

But, over the years since the 60's, these gas powered bicycles are
discouraged a lot by the government now. Most all the states treat any gas
engine powered bicycle as a real motor vehicle now, so you need to title,
register, get insurance and have a driver's license as well to operate them
on a road.

Many if not most gas-powered bicycles qualify as mopeds. In most
states, these have to be licensed (one time only), but do not require
insurance or a motorcycle endorsement to operate.

Quoted message said:

You might have better luck with the electric motor and battery
kits they sell though. The governments now tend to encourage those types of
vehicles. Many states let you ride a electirc bicycle or scooter on the low
speed limit roads wihtout having to title, register them or needing a
driver's license even.

Most states have settled on the Federal Government's arbitrary limit of
750W (1.0 HP) output and 20mph maximum assisted speed for an electric
bike to be legally classified the same as an ordinary bicycle.

Quoted message said:

Unfortunately some of those kits may still be tricky to install. But the
kits with the motor (motor in the hub) installed in the front wheel would be
the best one of the bunch to setup and use.

Front hub motors are the easiest kind of kit to set up, but the best
ones to use are those which drive through the bike's gearing. Examples
of those include the Cyclone kit (for single chainring derailleur
bikes) and Stokemonkey (for Xtracycle-equipped bikes). There are also
turn-key electric bikes like the Merida Powercycle and Giant LaFree
Lite that come with powered cranks rather than powered wheels.

http://www.cyclone-tw.com/
http://cleverchimp.com/

Chalo Colina

I agree with Ed's comment about self-power. Once I got to _enjoy_
climbing Upton Hill nearby, I found that one climb of the hill would
"power me through" an easy 25 mile ride. That is, the hill workout
reduced my intolerance to physical work; it increased my upper limit.

I motivated myself to climb the Hill by doing it at dawn, the prize
being the tremendous view of my area and the dawn colors.

I didn't so any body-building, I just got used to the feeling my legs.
No sweat, just feeling the burn. Really made a difference. At one point
I was limited to one mile rides. Now we do 25 almost every Saturday.
Jeff goes on to do another 20 or 40. Shees.

Doug

Werehatrack said:

You're adding needless energy loss unless you want the belt to be part
of a variable-ratio drive system. Keep the speed and grade-climbing
parameters within a narrow (but still useful) range, and you don't
need it.

I will note, however, that many belt-drive motorized bicycles were
made prior to World War II, and one common approach was to put the
pulley groove on the side of the rear rim, thereby providing a useful
gearing solution with minimal effort. Unfortunately, this requires a
wider rear stay spacing than is used on normal bicycles; a special
frame would be needed in order to employ it.

I have built a front wheel with a 26 1-3/8 tire on it and an inner
conentric rim off to one side having 24 inch nominal size. It is
centered quite well. This won't work with an MTB-sixed 26 inch rim, at
least not the farily deep-section steel rim on my old MTB. A less deep
aluminum MTB rim might work this way, providing a path for add-ons, at
the cost of relacing the wheel with the old spokes, a labor expense. I
still have this wheel and would like donate it to an experimenter here
in rbm or rbt.

Doug Goncz
Replikon Research
Falls Church, VA 22044-0394