I have certainly read about this technique in some Vincent tome. Can't recall whether it is Richardson or Forty Years On but I always do it when refitting the wheel.
oval drums - not?
- Thread starter davidjoyner
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Dave,
have you checked your wheel bearings?
Cheers, John
have you checked your wheel bearings?
Cheers, John
“As I rotate gauge:- set 0 at lowest point and it reads 15 thou at the highest point 180 deg away.
Both drums read exactly the same and the high point is at the same location in relation to the rim.”
The way I read the above in OP’s first post says that both the drums are somehow de-centred relative to the centre of rotation which is not to say that the drums cannot be out of round too but I’d be inclined to check their fit on the hub first.
Both drums read exactly the same and the high point is at the same location in relation to the rim.”
The way I read the above in OP’s first post says that both the drums are somehow de-centred relative to the centre of rotation which is not to say that the drums cannot be out of round too but I’d be inclined to check their fit on the hub first.
Th answer to Clevtrev's enquiry is that this does not apply to steel brake plates which are held in place with thin nuts. It would not do any harm, but as he points out, a half inch hole on a half inch spindle is not going to move much. However, electron plates, or any of the later aluminium replicas, have, or should have central holes not only larger than half an inch but also larger than the outer diameter of the hollow axle. These go over the outside of the hollow axle and the oversized hole is to allow exactly this kind of alignment. It is vital to do this centralising before the spindle is tightened. I suspect Clev knows this but is being his usual stimulating self.
Not really. The alloy plates go over the top of the drum, so that any movement is limited by the amount of the difference between the diameter of the drum and the recess in the plate. Then it gets noisy, the way the standard plates would if you tried to move them sideways, after one has carefully set the gap between plate and drum to get best water exclusion, and maximum shoe contact.
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If i omit to do it on my Ajay rear brake,its hopeless.The play between the spindle and the brake plate is not excessive, but every little helps and it makes a world of difference when done correctly.I leave the spindle just loose and spin the wheel by hand dabbing down on the brake pedal several times to "rattle" or settle the shoes into the optimum place, then hold the brake on hard as i finally tighten the spindle. Works a treat!
I may have lost the thread of this thread with all the posting tennis.
I also use the above technique to centralise 2LS brakes, but Trev has a valid point that there isn't 15 thou of movement available at the spindle. If the drums and hub spigots are round I'd tighten the spindle and slacken the bolts that fasten the drums to the hubs, then get someone to hold on the brakes (I'd go for brake, turn the wheel then brake again, and repeat a few times) while you tighten the bolts.
Good Luck
H
I also use the above technique to centralise 2LS brakes, but Trev has a valid point that there isn't 15 thou of movement available at the spindle. If the drums and hub spigots are round I'd tighten the spindle and slacken the bolts that fasten the drums to the hubs, then get someone to hold on the brakes (I'd go for brake, turn the wheel then brake again, and repeat a few times) while you tighten the bolts.
Good Luck
H
clevtrev is right but having just been out to the Walker shed and found some original electron plates and original shadow drums there is more than a few thou clearance between the outer rim of the drums and the inner part of the 'water excluder' part of the brake plate, 40 to 50 thou at a guess. I do not have a vernier that size and do not want to take the brake shoes etc off the plates, which also limit the total movement available, so I am not sure of the exact difference. The method of putting on the brake before tightening the tommy bar axle is what Vincents recommended for their racing brakes, but not the steel braked plates items.