Here is my question. I have 2 shimano freewheels. One is an old Shimano 6 speed, the other a newer Shimano 7 speed with the better stepped cogs. Is there any way I could take 6 of the new cogs and transfer them to the old freewheel?

I had the freewheel fixtured in a vise between 2 planks of wood (not to damage the cogs). I tried to remove a cog on the old Shimano freewheel using a chain whip. I could not get it to budge.

I know the easy answer is just to buy a new freewheel... But I read that people used to switch out cogs on freewheels.

Help? Suggestions??

This might help:

https://sheldonbrown.com/freewheels.html#replace

I've done this, but it was only to save one of the excellent Dura-Ace 7400 freewheels with a couple of worn-out cogs. I transferred some cogs from used current-generation Shimano Hyperglide freewheels, which only needed a little grinding to make them compatible. The result was a 7400 7-speed freewheel with Hyperglide cogs: the best of all worlds.

My recommendation: don't bother futzing around. Go to your local shop and get a 6-speed Shimano Hyperglide freewheel, which costs around $15.

Thank you, Pars for the link. I read it and will try it again. I don't have 2 chain whips but might use a spare chain in the vise to see how that works.

Dave, so how did you remove the Dura-Ace cogs? Did you leave the freewheel on the wheel and use 2 chain whips or did you have a fixture like Sheldon Brown shows on his article on freewheels? I know that it's easier to buy a new one, but I want to try to see how it's done.

I have a shop-grade freewheel vice tool that fits into a large bench vice to immobilize the freewheel. This allows the use of a single chain whip to unwind the one or sometimes two threaded outer cogs. Sometimes these cogs are threaded on so tight that you need to liberally apply penetrating oil days in advance, and then hammer on the chain whip - hard. It may not be possible to generate this amount of force/impact with just two chain whips.

Using a solid block of wood that fits into a bench vice, then you could immobilize the freewheel by applying some wood screws around the periphery of the outermost cog. This is basically how my freewheel tool works, except mine in made out of metal, and has multiple holes for the bolts that are used to immobilize different sized outer cogs.

Why kill yourself? Just get a new one. You live near Meijers, don't ya?

On sale at Meijers for $8.99.

That's a great idea, I'll give it a shot. Might leave it soak with WD40 for a couple of days. Thank you Dave!

Unfortunately the closest Meijers is 2hrs. away from where I live.

wd40 is not a penetrating oil or a lubricant. try 50% acetone and 50% Automatic Transmission Fluid for a super penetrating oil.

Be careful, though, that trans. fluid can be pretty caustic. It'll strip paint.