What is a "motor driven cycle" if not a motorcycle?

[Cluricaun]

I thought of this one while driving between Chicago and Champaign this weekend. I always see signs on the on ramps for interstates that say you cannot operate “motor driven cycles” on said roadways. However I always see people on motorcycles crusing along by me. Are all motorcyclists violating the law somehow, or is there a differance between your average Harley and a “motor driven cycle”?

[DesertDog]

Think moped, a motorized bicycle with a top speed around 30 MPH with a good tailwind. wouldn’t want one on an Interstate.

DD

[DeVena]

According to Colorado (and a lot of other states…)

Colorado Revised Statues Pertaining To Motorcycles:

42-1-102. Definitions
(55) “Motorcycle” means every motor vehicle designed to travel on not more than three wheels in contact with the ground, except any such vehicle as may be included within the term “farm tractor” and except a motorized bicycle as defined in paragraph (b) of subsection (59) of this section.

(56) “Motor-driven cycle” means every motorcycle, including every motorscooter, with a motor which produces not to exceed six brake-horsepower and every bicycle with motor attached, but not trail bikes, minibikes, go-carts, golf carts, and similar vehicles which are not designed for or approved by the department for use on the public roads or highways and not motorized bicycles as defined in paragraph (b) of subsection (59) of this section.

So basically, Harley = Good. Moped = Bad.

[crozell]

Though I couldn’t find anything official from the government in a few minutes of searching, this site seems to indicate that in Illinois, a moped is a type of motor driven cycle and has the following definition:

A motorized pedalcycle (moped) is a motor driven cycle. It produces two brake horsepower or less and has a maximum speed of 30 miles per hour. If the moped has an internal combustion engine, the displacement shall not exceed 50 cubic centimeters, and the power drive system shall not require the driver to shift gears.

I’m not sure what “brake horsepower” is (or how it is different from plain old “horsepower”), but it must be some measure of power. I’ve always heard motorcycle power quoted in CCs (cubic centimeters, measuring the displacement of the engine I believe?). I grew up in Michigan, and IIRC, the signs on the highway on-ramps specifically said something like “no motorcycles under 125 cubic centimeters”.

[Gary_T]

@crozell

I’m not sure what “brake horsepower” is (or how it is different from plain old “horsepower”), but it must be some measure of power.

From http://dictionary.reference.com/search?q=brake+horsepower&r=67 : “The actual or useful horsepower of an engine, usually determined from the force exerted on a friction brake or dynamometer connected to the drive shaft.”

@crozell

I’ve always heard motorcycle power quoted in CCs (cubic centimeters, measuring the displacement of the engine I believe?).

CC does stand for cubic centimeters, and it is a measure of the engine displacement (the combined volume of the cylinders). It is not a measure of power, although obviously the bigger the engine the more power it can produce.

[Charlie_Tan]

I give you the Danish knallert - a moter driven cycle if ever I saw one.

[occ]

Two common criteria for non-motorcycle er, motor-cycles, is an engine displacement of less than 50cc, and, in some cases, they must have pedals. This is why mopeds have pedals. Heh.