Chain slips / skips / grabs / runs rough ???
As you can see, I don’t know quite what to call it.
Here’s the deal: I cleaned my chain a couple of weeks ago with one of those Finish Line kits (the plastic body with brushes that you fill with solvent and run your chain through), and ever since then I’ve had a slip / skip / grab, but only on the fifth sprocket in the rear freewheel.
This is only when I’m peddling the bike, not when I’ve got the back wheel up on my mini-rack. I guess I can’t turn the pedals fast enough by hand to duplicate the force.
It doesn’t matter what ring I’m on in front (there are three) and the other six gears in back run great--really smooth and quiet. It’s only the fifth sprocket that I can hear and feel, almost as if the chain was rubbing on something.
I’ve readjusted my derailleur, including fiddling with the limit screws, but to no effect. (I had thought maybe it was rubbing the gear above, and that by adjusting the limits, I could adjust where it sat on the sprockets.)
The chain itself is in good shape. I checked it with the ruler method that I learned from Alex’s tutorial. And, while the bike is ten years old, I barely rode it the first eight years I owned it. The jockey wheels line up straight under each sprocket, so I don’t think it’s a problem there.
I’m assuming it’s a problem with the sprocket itself, so I looked at all the teeth very carefully, and, yes, some of them do look like shark’s fins (fins, not teeth), but none terribly so, and, besides, some of the teeth on all the sprockets look like shark’s fins -- and, anyway, I thought some of the teeth were supposed to be shaped like that? Is that right?
So, is there anything else it could be that I’m not checking? Is this something fixable, short of replacing the freewheel, or do I just need to learn to live with it.
One odd thing -- as a side note -- when I was adjusting the limit screws, tightening the L screw would move the chain towards the spokes. Luckily I have a plastic spoke guard, but it was definitely the case that if the screw was too tight, the chain wanted to hit the spokes.
Thanks for any help/advice.