Originally Posted by John33702

I appreciate all the replies. I see I didn't give enough of the right info. I'm looking to replace a cassette, not a freewheel. The bike shop installed an 8-speed cassette and a lever shifter but hadn't realized the chain would touch the wheel on the largest sprocket, so they set the low limit screw for the next sprocket. Before this, though, they sized the gearing incorrectly. The combination of the 44 teeth chainring and whatever cassette they installed made it hard for pedaling in the lower gears and impossible in the higher gears. I worked out the gear inches I thought I wanted and asked them to install an 11-28, 8-speed, giving me an effective 7-speed ranging from 11-26. Also changed the chainring for a 36 teeth. That gives me 94.9 gear inches in the highest gear, and 40.15 gear inches in the lowest gear.

I know how to work out gear inches but unless one knows how 95 gear inches feels (which the 11 teeth sprocket gave me) it was guesswork. Now that I know how it feels, I have realized a 12 or 13 teeth sprocket would be better. I'd rather be able to use all the gears than just some of them. So, back to the calculator. It seems there is no such cassette as a 12-26. The next nearest one is a 13-26, 7-speed plus the spacer. That will give me 40.15 gear inches on the 26 teeth sprocket (which I already knew I wanted) and 80.3 gear inches on the 13 teeth sprocket, which is a lot more reasonable than 94.9 gear inches. That's a struggle on a fat bike!

Being that I intend to change the cassette, I didn't know if there was a spacer that would go with the 7-speed. You answered that question, and I thank you. The Shimano lever shifter is 8-speed but that's okay because the eighth position won't do anything. I liked the lever shifter so much that I changed the twist shifter on my cruiser for a lever type. That has a 7-speed freewheel, and it works great.