0128220]Oh, wow... I think it's a mongrel. It's definitely got a Front Freewheeling crank, but the rear freewheel looks incorrect. I thought the FFS system only came with a FFS Uniglide cluster- that one has an earlier skip-tooth Shimano freewheel. I also thought that the FFS system was combined with Shimano Positron II shifting- that one has a Schwinn friction shifter and a Shimano Titlist (?) rear derailleur. Did Suburbans ever come with FFS? I'm getting hazy[/QUOTE]

It is not a mongrel. That is the original version of the friction freewheel, with the 28AT cog. It was introduced prior to Uniglide cogs (which came out in 1978 but weren't used on the friction freewheel until 1980). The rear derailleur is the 400FF, which was a friction derailleur specifically designed for the front freewheel system. Positron was introduced prior to the FFS and the two, though often paired, were independent systems that could be used on their own. The presence of a friction freewheel with the 28AT cog and a 400FF rear deraiilleur suggest this bicycle is circa 1977-1979.

The 400FF rear derailleur on your bicycle uses a standard cable. The Positron rear derailleur used a solid, push-pull cable because they did not have a return spring.

It is a FFS crankset. Shimano offered FFS cranksets in Ashtabula, cottered and three piece cotterless versions.

On the contrary, both Positron and FFS were solutions to valid concerns. Both products were introduced on the heels of the big boom. There were a lot a cyclists intimidated by derailleur gear sets. They were either new to the sport, accustomed to coaster brakes or, at best, familiar with (indexed) 3 speeds. For most them, friction shifting was a complex process of numerous actions. Positron eliminated the fiddling with the shift lever, allowing them to their eyes on the road. FFS allowed them shifting while coasting. They did not have to pedal at what seemed an abnormally high cadence and then soft pedal to execute a good shift. If they absentmindedly resorted to their 3 speed habit and back-pedaled to execute the shift, it worked. If you left your bicycle in too high a gear at the end of a ride, you could shift into a lower gear while walking the bicycle and did not have to start the ride in too high or gear or try to change gears while lifting the rear wheel and simultaneously pedaling and shifting.

Having been raised on derailleur bicycles, most of us consider the process of friction shifting as second nature. But having sold them during the boom, I can assure you that it caused a lot of anxiety for newcomers, particularly adults. Positron and FFS alleviated some of these fears and facilitated a transition into the sport that otherwise might not have happened. Both systems actually worked well. They did what they were supposed too and repairs or complaints were rare. Both designs had a relatively long life and lasted until the introduction of SIS, so I don't understand why everybody is constantly referring to them as failures.