Author Topic: My linear-pull brake arm had jammed outboard bearing  (Read 693 times)

My linear-pull brake arm had jammed outboard bearing
« on: 19 April, 2024, 06:15:45 pm »

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.


LittleWheelsandBig

  • Whimsy Rider
Re: My linear-pull brake arm had jammed outboard bearing
« Reply #1 on: 19 April, 2024, 06:41:54 pm »
Clearances are tighter with these pivots, so the brake arms don't rattle on the bosses. Dia-Compe 986 (back in the early '90s?) was about the first model of cantilever brake I became aware of that didn't pivot on the fork/ frame boss but no doubt there were earlier examples.

We have a wide range of Tektro mini-Vs here to compare. Cheap ones pivot on the boss (jam up quickly and rattle), medium models have plated steel pivots (take a little longer for dirt and corrosion to jam them) and the most expensive use SS pivots (still jam but rarely).
Wheel meet again, don't know where, don't know when...

Re: My linear-pull brake arm had jammed outboard bearing
« Reply #2 on: 20 April, 2024, 11:07:18 am »
Thank you for replying. The inner hollow spindle(?) in my case is not stainless steel since it had produced brown paste which I presume is rust. If it were originally plated, that is now gone, so they will corrode quickly and jam again. Suggestions for models  of arm using stainless bearings would be gratefully received; these are full size, not mini-Vs, BTW.

LittleWheelsandBig

  • Whimsy Rider
Re: My linear-pull brake arm had jammed outboard bearing
« Reply #3 on: 20 April, 2024, 01:53:56 pm »
No idea. There are not many decent quality V-brakes made nowadays.
Wheel meet again, don't know where, don't know when...

rr

Re: My linear-pull brake arm had jammed outboard bearing
« Reply #4 on: 20 April, 2024, 05:05:31 pm »
SHIMANO DEORE XT V-BRAKE Caliper for Trekking BR-T780
Look like they may have the bush that you want and seem to available to buy.

Re: My linear-pull brake arm had jammed outboard bearing
« Reply #5 on: 20 April, 2024, 06:42:20 pm »
Boat trailer grease might help and resists moisture  :)
the slower you go the more you see