Bicycle Mechanics - Ratchet mechanism in a chainwheel?

Bikeforums.net is a forum about nothing but bikes. Our community can help you find information about hard-to-find and localized information like bicycle tours, specialties like where in your area to have your recumbent bike serviced, or what are the best bicycle tires and seats for the activities you use your bike for.



PDA
Alzonder
08-19-07, 10:57 AM
I got this bike from a neighbor and it has the ratchet in the chainwheel whereas the "free"wheel is fixed.
I remember reading about those somewhere but cant find anything anymore on the web.
Any info?

HillRider
08-19-07, 11:03 AM
Shimano made a "Front Freewheel System" for a brief time in the early '80's. Here is Sheldon Brown's glossary page that describes it: http://sheldonbrown.com/gloss_e-f.html#ffs Scroll down to the appropriate listing.
Bikedued
08-19-07, 11:06 AM
Some old Schwinns had them. Interesting concept, but they decided to put them on damn near the lowest end bike they made. Made no sense. Maybe it was a test model to see if it became popular. Not many bikes have it, although a I saw a Huffy recently with a FAKE one, lol. Looked like the schwinn model, but the crank wasn't able to spin backwards at all.,,,,BD

Alzonder
08-19-07, 11:29 AM
Great! Thank you.
Yeah the bike is not anything special. Steel rims.....no name.
I've had a Panasonic bicycle with the same system. That bike was really well made.
Conveyor Belt
08-19-07, 01:27 PM
Cool. I wonder why it didn't catch on? Sounds like a great plan... being able to shift without pedaling would decrease the torque put on the system when shifting on uphills.
Wordbiker
08-19-07, 01:42 PM
Cool. I wonder why it didn't catch on?

Most likely it was the poor shifting due to the low quality of the components. Couple that with the inability to stop the chain motion when your gears got tangled (which they invariably did) and many of them ended up in the landfill.
Sheldon Brown
08-19-07, 02:15 PM
Cool. I wonder why it didn't catch on? Sounds like a great plan... being able to shift without pedaling would decrease the torque put on the system when shifting on uphills.
Coasting while going uphill is generally a sign of an incompetent beginner cyclist. Those who do it are throwing away momentum that could help them get up the hill.

This system went away because it was a "solution in search of a problem."

Back in the day, many cyclists new to derailers though you _had_ to coast to shift. (A hangover from internal gear hubs, where many people belived that was the right way to shift them.) Instead of teaching riders how to shft correctliy, Shimano created special hardware as a workaround.

Sheldon "Why Bother" Brown