I recently got a 19t freewheel for my rob roy and the chain is slack at 2 points in the stroke and tight at 2 points (imagine there's just 4 points and I think you'll get my meaning). If it's tensioned enough so the chain won't fall off at the slack points it's too tight at the tight points- way too tight. In fact it damaged my chainring (but I just flipped it around, it's symmetrical). I tested it w/ my 18t freewheel and a 18t and 20t ss cog on a road hub and the same problem is slightly there, but it's nothing like with the 19t cog.
So I check out the cog closely and it seem maybe, just maybe, at a couple points the troughs of the teeth are cut lower than elsewhere- this is probably the slack points. It's a real small difference, like 1mm maybe, but apparently it's enough so I'm trying to get a replacement and see if it's better.
Anyway, I'm wondering if anyone else with a "true" ss (that is track ends or horizontal dropouts) have had this problem? I'm just curious because I'm wondering if the rob roy is right for me after all, I've been having some fit issues with it, and if I go w/ a different ss bike next year I'm wondering if a regular frame w/ a tensioner is the way to go just to avoid the issue altogether.
These are ACS claws freewheels I'm using, don't particularly want to spend $70 on a white bros. freewheel, and w/ the tuggnut making wheel changes slow and the tension issue I'm wondering if there's an advantage to track ends at all. I know tensioners have their problems but if you keep the chain as short as you can it seems maybe it's the more sensible way to go for racing.