Sears (Puch) 5-speed townie
 

Here's what the corner thrift coughed up this week for $30: an old ('68-'72, I think) Puch & Roebuck 5-speed. Straight tin, good chrome, lights even work, still got the original Semperit whitewalls. It's got an old Shimano Lark derailleur, plus something I've never seen before; the spoke protector is labeled 'Speed Selector' and has a slot in it marked 1 through 5 (see pics). Above the slot it says 'Turn this disc to select gear changing point'. What the heck is that?! Anyone know anything about it?

Goes down the road great. And check out that chainwheel; the bugger's the size of a manhole cover.

http://home.comcast.net/~mswantak/ws...7/site1494.jpg

http://home.comcast.net/~mswantak/ws...7/site1495.jpg

http://home.comcast.net/~mswantak/ws...7/site1496.jpg

Cool bike, have no clue what the spoke protector is about, kind of neat though!

Wow, what a classy bike! Makes me want to dig out one of those old sweaters mom used to buy me (you know... the ones you would never wear) and go for a ride. :D

Is that upper unit on the rear fender a tail lamp? Very sweet!

Talk about a time machine! Very cool find, Mike. You'll be cruising around with a pipe in one hand, I imagine (and not a water pipe, either).

Neal

The spokes are a little rusty. That spoke protector is a marketing gimmick.

Now that is just plain neat!:D

Ya think? :D

And it's pretty obvious that Speed Selectis a marketing gimmick, but what I want to know is how was it supposed to work?

Thats cute! Looks like the front chainring is a 52 tooth even so you can get the 'ole thing to fly!

Is it possible that the speed selector is a kind of auto-shift device? It kind of sounds like the mechanism that is described for "Auto-bikes"....the disk flexes with speed and nudges the derailleur to shift**********

I have the one-speed version of that bike.

Cool.

The disc doesn't flex outward like an Autobike's though. I pulled the rear wheel tonight in the course of detailing the bike, and where you'd expect to put the puller to yank the freewheel there's a stainless dust cap with 'Automatic Five' and '333' stamped on it. In the driveside end of the axle is a screw marked 'oil', where I suppose you lubricate the freewheel. Here's the really odd part. Like any other freewheel, it spins freely in one direction. But when you turn the freewheel in the opposite direction, instead of engaging and trying to turn the wheel, it spins the axle in the opposite direction.

If it is some sort of autoshift, it clearly isn't doing anything; it rides and shifts like any other bike. Weird; can't find anything about it on the web, either...

Interesting and delightful find... and for $30 too! :)

The 333 marking is indicative of Shimano. Is there anything acted upon by the disc?

I must admit to curiosity getting the better of me. :)

Here's a cronologic reference ofr 1965. http://www.bikemagic.com/news/article.asp?UAN=1955

Patent information: http://www.freepatentsonline.com/5295916.html I'd love to see the drawings.

The cited patent (1992-1994) is 25 to 30 years too late for the mechanism pictured.

The clue here is that the freewheel drives the rear hub via the axle, rather than directly. I suspect this rear hub includes a Model T style 2-speed epicyclic system, but with a centrifugally set automatic shift point. The manual rotation of the spoke protector determines the wheel (and therefore ground) speed at which it shifts into the high gear range, which is probably direct drive. As you hold the wheel and turn the cogset manually, you are engaging the low gear range, via the reduction gears of the epicyclic gearset. Thus, you have a conventional 5-speed manual transmission with two automatically-set ranges.

The fact that there are coincidentally 5 click-stops on the pie plate and 5 cogs on the freewheel perhaps confuses the issue a bit.

Try riding it and see if you can discern a (noticeable!) shift, probably from a 4:3 reduction to 1:1, about the same as a Sturmey Archer AW going from 1st to 2nd or a chainring switch from 39 to 52. (There's another hint: instead of a typical 46T compromise chainring, this thing can use a 52, because the reduction system provides the missing matching 39 or 40T small ring.)

Hmmmm; fascinating. When I get it cleaned up and screwed back together I'll set it on the lowest setting and see if I can get it to do anything.

Maybe that allows you to decide which cog you want to be on when it goes from low to high range, like when I'm in 5th gear and reach a certian speed I want to switch to the higher range, ie 10th gear. Does that make sense? I guess so if you want you can go directly from 2nd gear to "7th" gear.

True... I did over look that :o There was another on the same site that did have an earlier date IIRC.
Nonetheless, it's a unique of bicycle drive line history. I'd say it's a keeper! I've never seen anything like it.

It will be interesting to see a 'report from the saddle'.

There is no discernable way for the rear hub to sense either the position of the derailleur or which cog the chain is engaging. If it were my bike, I would put it on my workstand with the pieplate in #1 position and the chain on the smallest cog, accelerate the cranks gradually to a rapid spin, and hope to get the mystery hub to do something. If I am correct, at startup, the freewheel cogs will rotate about 33% faster than the rear wheel; past the shift point, the cogset and the rear wheel should rotate at the same rate, as on conventional freewheel systems.

Well, I put a couple miles on it and if the hub is doing anything, I can't discern it. I'm thinking perhaps the alleged planetary gears haven't seen any lubrication in a long time. I'll shoot some light oil in the axle and see if it changes anything.

If the freewheel cogs rotate faster than the rear wheel, then the planetary system is working. I suspect the centrifugal shifting mechanism is frozen from lack of lubrication. If so, then you are on the right track.

I'll have to file that along with life's other great unknowables: I sold the Puch today for $140 to a woman who drove all the way down from Napa. My burning curiosity will have to be sated by a quick $110 profit. :D

Now we will never know the mysteries of the "select-o-matic" dork disk. :(

Congrats on a sweet flip! :beer: