Wierd freewheel
 

Can anyone comment on this fw? I suspect the 2 large cogs are to mesh with every other chainlink, so they would act like 28 & 34 tooth cogs?
http://cgi.ebay.com/Vintage-Shimano-...3A1|240%3A1318

The skip-tooth on the larger cogs was done to improve shifting onto these cogs. This was pre-Uniglide/Hyperglide stuff.

EDIT: ^^ + 1 ^^ and they act like normal 28 and 34 tooth cogs when engaged. Sorry, typo on the #s.

How is that? They have the circumference of 28 and 34 tooth cogs. Only every other tooth engages, but diameter is what denotes effective cog size.

Freewheels with skiptooth cogs like that on the two largest gears, came standard on the Schwinn Sports Tourer brazed-frame road bike of the 1970s. My parents bought one new for my brother in 1972, and it had such a freewheel. My brother currently has no interest in it, and it resides in my garage :) when I'm not riding it around the local lake bikepath.

I figure there's an even chance that that one on Ebay, came off a Sports Tourer. I don't know what other bikes they came on (The ST's near twin, the Super Sport, came with a 14-32 that has 32 teeth on the largest cog, not 16). There was Schwinn Superior of the same era, basically a ST without a kickstand and with downtube shifters. Don't know if that one had the skiptooth freewheel or not.

No. The crucial bit isn't no of teeth, but diameter. Usually the teeth no follows the diameter, so counting teeth is an easier number to compare than diameter. In this case however, the OP is right that gearing wise they'll act like 28T and 34T sprockets when engaged.

Either this was a lame joke or you need to go back and study more mechanical theory.

I lived up a tall hill in San Jose 'way back then. Always hated riding the basic Varsity up that hill. Standard technique on that hill, was to crisscross back and forth across all lanes, for brief rests when going east-west between the times of riding up the steep part going north. Was a ***** when a car came by, you had to ride straight up the hill, which I couldn't hack so usually had to get off and walk till the car was gone.

The first time I did that hill on my brother's Sports Tourer, I shifted to the smallest chainwheel on the front, then went to the largest on the rear. Though I was going slow, the pedals spuns so fast, and with such little resistance, that I thought the chain had fallen off the sprockets. I actually stopped and got off the bike to put it back on... only to find it was still correctly in place, exactly where it should be.

Got back on and rode straight up that damned hill, all the way to my house.

There's a lot to be said for wide gear spreads, whether on a mountain bike (where they're often standard) or a road bike (where they almost never are, ST was a rare exception in the 70s). And it doesn't make the slightest difference whether half the teeth are missing or not.

BTW, I just got one of those 14-38 five-cog freewheels on Ebay (there's another in auction No. 180322499904), and a Huret Duopar rear derailleur which theoretically can handle it. My Super Sport (my use-and-abuse bike) is going to get a makeover soon. Hope it works.

My parents lived about 2/3 of the way up a rather steep hill when I was a kid and my bike was a single speed balloon tire J.C. Higgins (Sears' house brand, actually made my Roadmaster, IIRC) that weighed more than I did. The only way I could ride it up some of the hills was to zig-zag as you describe. The local drivers knew to watch out for us and would usually wait while we ground our way to the top.

I was in my 40's when I finally got a bike that had enough gearing to avoid that problem.

I got a freewheel like that on a puch racer

I bought a few of the 14-38 on ebay. Just have to get a super range rear der to handle it.

What rear derailleur did you use?

I've heard that the old Huret Duopar is supposed to be able to handle it. Are there any others?

am trying a Tourney seen here
http://www.jensonusa.com/store/produ...erailleur.aspx
I was using a shimano xts and it went up to 38 OK but wouldn't come down, wierd.