Cyclo Benelux

[wrongway]

I have a Cyclo Benelux Derailleur that I've used and taken off and then thought about using it again. It is from 1957, I believe. If I wanted to change the gears on it, and I assume I could, how would I know what to look for? What would I measure to get the right size of threads? The gears thread onto the 'cassette'. This is used along with my Sturmey Archer AW hub.

 

[dnc1]

Do you have any photos of the freewheel/cluster?

 

[bulldog1935]

@LouB may have an answer for you, also maybe @petritl
Sounds like what you're looking for is a wider-range freewheel.
It might be easier to find fewer toothcount chainset (chainring).

The Brits notoriously like tall gearing on their club racers.
Lou tackled this question on his '60 Lenton GP, may have changed the freewheel, but definitely changed chainrings.

 

[wrongway]

Do you have any photos of the freewheel/cluster?

I'll see if I can get one loaded.

 

[wrongway]

Last night I tested it out with a 52t chain ring I had and the 23/19 Benelux block on the AW Sturmey Archer hub. Not bad. I think it could work well, but the chain was slipping on the high side. Not the S/A hub, just the chain. Odd.

 

[wrongway]

Here is the best photo I have right now.

 

[wrongway]

I realize that's not the best picture. The block is for three gears. They thread on like normal threads and are: 23, 19, 15. I don't have the room to keep the 15 on as it rubs the frame and spins itself off loose. That's ok. I really only want two anyway. I was really surprised at how lively it felt! I almost 'spun out' in 2nd gear! This puts the gear inches at: 58.7 - 70.9. Still puzzled as to the chain jumping while in the high side. Maybe some more tweaking.

 

[bulldog1935]

chain slipping could be cog wear, and possibly stretched chain.

 

[wrongway]

chain slipping could be cog wear, and possibly stretched chain.

Well.....this set up was working before I took it apart, changed my mind and put it back so I'm thinking wear might not be an issue. I should try a new chain or are you saying that I don't have enough links in it?

 

[bulldog1935]

nothing of the like. Simply thinning of the cog with wear, and stretching of chain links combine to cause chain slipping under high load.
A new chain is never a bad idea, and if you do find a freewheel to swap, a new chain at the same time would be imperative.

Call the guy at Yellow Jersey. He may understand your drivetrain more than anyone else around. He also rebuilds freewheels, and who knows what he has for parts in far back bins. He rebuilt my SunTour Winner 7 freewheel and changed a cog size for me.