Freewheel cog threads
 

iirc, the small cogs have right-hand threads, the last large cog has left-hand threads.

Confirm or deny?

I'm sure they all thread on to the FW body clockwise so pedaling the bike will always tighten them.

Chombi

I thought the back was left threads to provide a means of tightening the last cog with a chain whip.


I need to remove the last cog and since it is never easy, I need to be certain before I start cranking on it.

I never had a FW with the last, biggest cog threaded on. usually they just slip on to three big splines on the body so they should provide resistance from turning when using chainwhips. What kind of FW do you have that might have a threaded on biggest cog??
My FWs usually just have the smallest one or two cogs threaded on and maybe the fourth one too, but never the biggest, last cog.

Chombi

All old 3-speeds. Regina, Atom and Cyclo.

You would be correct, Iab. If the last (largest) cog is indeed threaded instead of splined -- and yes, that does make it really old -- it will be left-hand threaded. It screws onto the back side of the freewheel body, the hub side, where it comes to rest against a shoulder and so has to be left threaded in order to be not unscrewed by pedaling force. I've never seen one of these but I remember reading about them in by-then obsolete books during my "indoctrination."

OK, maybe that's why....
My cyclo brains pretty much ends at around 1972ish.......anything older might as well be as mysterious as Stonehenge to me....

Chombi

Good to know. I was going to take a peak in my old Sutherland's, but I don't believe they cover older threespeed.

Another thread with reference to old regina FW using lefty thread;
http://www.bikeforums.net/showthread...ina-freewheels

Splined cogs are such a better idea, I hate dissasembling old FW that require most every threaded cog to be whiped to unscrew.


Idea I have been playing with lately is to setup a freewheel with just two cogs, say a 15t and a 19t. Use with a double crankset with the chainrings having same differential # of teeth, so maybe a 42t and a 46t. Then, set it up as a derailleur-less a singlespeed bike in one set of the gears but you would be able to get off, move the chain to the other set of gears and effectly have two gears to quickly choose from without needing to alter the chain length, not need a special flip-flop hub. Should work well to setup with one general cruising gear and another lower climbing gear to help get up any hills. Same idea could even be applied with a triple cranks and custom 3-speed FW to get a 3x1 speed.

It's not exactly what you're talking about, but for something along those lines check out the White Industries DOS freewheel. Pretty cool, I think. And pretty pricey!

Thanks for the tip, bit of seaching on WI ENO DOS led me to this thread which discussed using it with a double crank as I had also envisioned;
http://forums.mtbr.com/singlespeed/w...el-710272.html

Downside of the DOS (Besides cost) is that only couple of teeth # options are offered and the two cogs only differ by 2 teeth. Need a bigger spread of teeth if you want to be able to climb steeper hills and cruise fast. By making up a 2x1speed freewheel from an old freewheel, you can have bigger selection of cogs available, make up most any custom combination desired.

http://www.os2.dhs.org/~john/fw-cog-thread-0002.jpg http://www.os2.dhs.org/~john/fw-cog-thread-0003.jpg

Credit: Sutherland's 4th edition

I don't know about what John posted, but this is what I have found out.

The two outside cogs of a 3, 4 and 5 speed freewheel will have left hand threads and are interchangeable. I removed them last night. You will see in the pictures, Regina had the outside as position "number 3".


http://bikeforums.net/attachment.php...hmentid=258684http://bikeforums.net/attachment.php...hmentid=258685

Also, the outside cog of a French-threaded Atom is not compatible with an Italian-threaded Regina.

Vive La France!