Originally Posted by
FBinNY
Park doesn't make the right tool. Older Shimano freewheels take a remover of significantly smaller diameter. The giveaway si looking straight don the axle. If the freewheel's spline diameter is as small or smaller than the axle locknut. That means the modern thin wall removers that fit between the axle and freewheel can't work, and you need to start by removing the locknut to access the freewheel, then using one of these
Note the thick wall, and 10.5m ID which clears the axle but not the cones or locknuts.
BTW- these are had to find and can be pricey, so your best bet might be to bring the wheel in and let a shop or co-op remove the freewheel for you.
Ummm... Shimano freewheels that required the FR-1-style tool went away in the early '80's. After that, they all used the FR-5-style. I'm pretty sure that WSI didn't start selling Diamond Back mountain bikes until the mid '80's. and "hybrids" didn't show up until the early '90's or so.
I'm going to bet on either a slightly bent axle or a gunked-up tool cavity are causing the problem.