I think my linear-pull brake arms are some model of Tektro's
Quartz range. One arm was very well jammed, so I loosened it on the canti boss...but it still wouldn't rotate. "Odd," I thought. On inspection, it isn't designed to rotate on the canti boss like every other brake v-brake and cantilever arm I've seen, since it has a solid pin that locates in the spring hole of the fork. To enable rotation, it has a secondary sleeve bearing, the outer wall being brass or bronze and the inner is steel. It was corroded. I've managed to drift it out and clean it up, but what a pig of a job to drift out a somewhat thin-walled hollow steel tube without marking or damaging anything. I'm left wondering what the advantage of this design is, and is there a better way to seal or lubricate it so that this doesn't recur? If the machine screw head were the right diameter, the washer/dust cap could be removed, the bolt replaced in the canti boss, and the screw head used to pull the inner sleeve out cleanly, which might allow maintenance in the field.
