How to Overhaul a Loose Bearing Square Taper

I did want to show you kind of an original type of a bottom bracket. This is what early mountain bikes all have. With this system, you have just one set of bearings on the either side that are balls and the retainer or they can be completely loose; you don't actually need this retainer. This one tightens in and of course, this one is the reverse thread and so it would, it threads in counter clockwise. And one of the big problems with this system was installing the fix cup properly. If you are a home mechanic, the only tool that you would have to do it would be this tool and there is really not enough purchase on it. To really tighten it is tight, do not loosen up without it slipping off of there.

On the other side, the bearings would go in, cover them with grease, you put them on in the spindle, run it through there. Put the cup on, on the other side. Of course, you'd would want the bearings to be clean and in here to clean these completely and put new grease in. This is the plastic sleeve you put in and the bearings go in here. Thread that in and then you tighten it in with the pin tool and you go until the bearings are snugged up and then put the lock ring on.

Once you get the adjustment right and you check and make sure that there is no play in there but it is also free to turn, there is no binding, then you hold the position of the adjustable cup at the pin tool and you tighten the lock ring with the tooth spanner until it is very tight and it is not going to loosen up. The fix cup is already tighten in on the other side and then if some plate develops again, which sometimes happens because you are tightening the lock ring against the shell and start pushes it outward a little bit, then you can turn both of them together a bit or you loosen the lock ring, tighten in the adjustable cup and then tighten the lock ring down till you get the adjustment perfect. That's how you do an old styled standard bottom bracket.

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