Peter Jourdain asked about the first version Cyclo Benelux Tourist rear derailleur regarding the number of speeds, freewheel tooth range, and max tooth difference between front chainwheel and rear cogs. The Dancing Chain has limited information. Scott Goldsmith responded with catalogue information. Here's more information.
The 13-26 freewheel range specified in the catalogue for 'fork end fitting gear' refers to bike frames with the Cyclo Benelux dropout. This dropout has an unthreaded derailleur mount, looking like Simplex.
As Scott said, mounting it below the chainstay with a Cyclo chainstay clip allows 28 tooth freewheel cog size.
If you are using the derailleur hanger that comes with the Tourist derailleur itself, you won't be able to use a 26 tooth freewheel cog in my experience. A Cyclo Benelux dropout situates the derailleur lower than using it with a derailleur hanger, thus allowing a larger freewheel cog size.
The derailleur has a 35 tooth capacity, so whatever freewheel cog range you use can be subtracted from that to give you a max chainring difference.
It comes in three speed 1/8 inch, four speed 1/8 or 3/32 inch, and five speed 3/32 inch models, so you would use the appropriate one.
Peter
Peter Brueggeman
La Jolla California USA
4peebee(at)peterbrueggeman.com