Not sure if this has always been around, but when I converted one of my steel bikes over to 700c wheels a few years ago, I was told there was no option for a 6-speed cassette so I had to use a 7 speed. This popped up on Amazon and I assume it fits that need for people converting old 12 speeds to newer wheels? Does anyone have any experience using one of these on a newer wheel set with Shimano hubs? It would be nice to get my bike working with the original 6 speed that I had with the original wheel set and 6 speed freewheel.

High Performance 6 Speed Bike Cassette with Stainless Steel Aluminum Alloy Replacement Cycling Accessories for Mountain and Road Bikes : Amazon.ca: Sports & Outdoors