Originally Posted by
lil'hobo
FBinNY, thanks for the idea. I just checked the cups and they are in there nice and tight. No movement at all.
.... I almost think that the upper race (the lower nut that adjusts the preload-whatever that's called) might be the problem. This headset, a Toro brand with a allen key clamp type of lock nut, was always super sensitive to how tight you put the lock nut on. It will feel almost perfect until you start to tighten the allen key. Then, the steering gets too tight. It's a weird design. I think that tightening the allen key warps the upper race or whatever resulting in the play or stiffness. I don't know.
It doesn't warp anything but pushes the cup off center. This is a flawed design. The remedy is to try to adjust the headset and set the locknut (if it has one) without using the set screw. If it tends to loosen over time, you can use some rubber cement on the threads to help it stay home.
The other approach is to buy a cheap headset, and use the upper assembly only, keeping your still good lower stack until it dies, then changing that to the new. Since only the lower stack normally wear, you can use the same upper stack forever.
BTW- the other thing to check is for a bent steerer. Needle bearing headsets are especially sensitive to mis-alignment. Spin the fork and see of the top cup wobbles. If so your steerer is bent, probably from a crash and you didn't notice at the time.