I have decided to use Suntour Freewheels. I have a Suntour Winner Pro freewheel. 7 speed. Trying to change the cogs to larger ones - I can only get 2 large cogs (splined) and 4 screw on cogs onto the freewheel, I can't get the 7th one on, unless there is no space between the outer cogs. I checked the thickness of the cogs that I have swapped, they are no wider. The only thing I can think of is thinner spacers or find cogs without spacers attached, as unfortunately some of the cogs have spacers attached. Any ideas?