brake shoes

I am trying to get close to full contact with the brake shoes to the hub, front and rear.
I have put sticky back sandpaper on the drum and lightly applied the brakes while turning the wheel by hand. Both shoes look like they are making the same contact ( I draw stripes on the brake shoes with a felt pen) . However, as I turn the tire I can feel spots with more and less resistance. As I increase the brake pressure it gets a lot more even. Wear on the shoes look the same. The drum/sprocket is brand new and made in England no a cheap knock off.
FRONT SHOES. Very difficult to get them to contact the drum at the same time. There are two adjustments in the brake rod, one at the short arm then another at the long arm. I would guess there is no difference between the adjustments, they both move the short arm in or out. Correct?
So my next method (again with sandpaper glued to the drum) is to do one shoe at a time, getting at least 3/4 contact. Then try to get them to touch the drum simultaneously. First time doing this so if anyone has been through this process, please advise.

Just a thought - have you checked how truly circular the drum surface is?

the rear drum is new...fresh machined surface. I know, double check, but I don't have a lathe big enough. As for the front, I had it turned at the local brake shop. I had a steel bushing installed in the brake plate to give .002 clearance on the axle...trying to eliminate variables. I must have removed and replaced the front wheel 10 times.

I'm assuming you know the trick of squeezing the brake on tight and hold it on while tightening the axle nut? If you don't have a second person you have to bind the lever against the grip.
This centralizes the brake plate in the hub.

I did that on the rear. Hopefully the bushing I installed in the brake plate eliminated the need for centralizing

Has this problem only showed up since the bushing was installed?
If so I would question if the centre of the bushing matches the centre of the shoe set.
I'm not convinced about the precision of manufacture of Norton brake plates.
Some looseness in the hole in the centre of the brake plate together with the process outlined above, though crude, does achieve the result.
If you're using a close-fit bushing you may have to get the shoes skimmed, while on the plate, to match the centre of the bush.
Others may have a better idea?
Cheers
Rob

Sounds like you have the twin leading shoe brake (TLS). Use a handlebar lever with no bigger than 7/8" between the cable nipple and pivot centers. Use a new HD nylon lined silicon fluid lubed cable. Don't use flat bars that drag cables over the tripple tree .Ensure levers are directly in line with arms when in riding position. After adjusting linkage as per book, try brake with linkage adjusted a couple of turns either way. Clearance to axle is more usefull on the SLS brake ,but too much clearance will not help at all. A longer arm helps the SLS. I have extra drain holes at the back of the hub which help remove dust.

it is the TLS. Originally I had new linings put on and the drum turned. I used my usual method of adjusting the brake shoes and it stopped very well so I rode it last summer. during the winter I pulled off the brake plate and discovered that I was using perhaps 2/3 of the surface of one shoe and maybe 1/4 of the other shoe so there is the potential of much better braking if I can get perhaps 3/4 or more of each shoe bearing on the drum. I was hoping that if I marked the linings, with a lot of patience, I can accomplish this. By the way, there is a stiffening kit in the drum. This sandpaper method was recommended by the local brake shop, the owner is a BSA man and has used this method on his own bikes.

In playing with the brake rod adjustment, I was able to make one shoe rub before the other and make the other one do the same. ( This is a poor man's method of arcing the linings. Vintage Brake is booked up for months and is very expensive. ) So, plan #2 was to get one shoe fully scrubbed in (once the felt pen markings disappear) then back it off and scrub in the other one. Then pull out the sandpaper and try to get both of them to hit the drum simultaneously using the brake rod adjuster.

Sounds like a reasonable plan to avoid cost and delays in shoe skimming.
Maybe use a more aggressive grit to speed up the process?

I am using [HASHTAG]#120[/HASHTAG] grit.

More elbow grease then...

re; ” FRONT SHOES. Very difficult to get them to contact the drum at the same time.”

Sounds like you have 2 different brake shoes from 2 different bikes, wouldn’t do it your way, if they are that far out seek out someone with a lathe and take your drum , brake plate and wheel spindle, it’s a 5 min job on a lathe to skim them down, but advise you to make slippers for shoes, and use .020 thou shims under each flat of brake shoe and skim down to EXACT size of drum. Then remove .020 shims.

Then file 30 degree chamfer on EACH leading edge-that is how the professionals do it

There is a Norton technical bulletin somewhere that says there should be 1/32" play between the front spindle and the brake plate. This allows the shoes to centre in the drum when brakes applied before tightening up spindle nut. I reamed my brake plate to get the 1/32" clearance and it made a big difference to brakes' performance.

Well if its a TLS then all you have to do is adjust the rod so both shoes begin to move on the brake plate at the same time .. then install wheel pull brake on to to centre the plate on hub.. Any discrepency will soon wear in... This simple and obvious way eluded me for years!

My usual method was to install the wheel, apply the brake and tighten the wheel spindle nut. Then, remove the brake rod from the short arm. Using two wrenches on the actuating arm nuts, move the shoes simultaneously out to where they just touch the drum. Then adjust the brake rod accordingly. Road test, then try turning the adjuster one flat in then one flat out looking for a slight improvement. This seems to work well but after inspecting the shoes at the end of the riding season I discovered that there was quite a bit of room for improvement. I had marked the shoes with a felt pen, drawing stripes across the linings which made it quite clear where the wear is. Discrepancies do not wear in quickly! You just end up with less than optimum braking.
My current theory is to mount the wheel/brake assembly, with sandpaper, back off one shoe and lightly apply the brake until the shoe has been sanded for it's full length. Then back it off, adjust the other shoe so it hits first and sand it for it's full length. Then remove the sandpaper and adjust the brakes so they touch the brake drum simultaneously. Mark well with a felt pen and road test. Much R&R of the wheel. Helps to have a second pair of hands. You start working as a team and find many small short cuts so the process goes quicker.

Well your usual method is what I had always done, but find I am getting better results by above , al least where lowish speed is concerned hav enot tried high speed as yet.

Re; “Discrepancies do not wear in quickly! You just end up with less than optimum braking”

The is a reason for this, that even AFTER you have adjusted the 2ls rods, the shoes were not skimmed down on a mandrel in the first place to the EXACT diameter of the brake drum, as I wrote in my first post on here. Believe me this is IMO the only way to get maximum performance from a drum brake that has no eccentric adjusters.

Re; “been sanded for its full length. Then back it off, adjust the other shoe so it hits first and sand it for its full length.” Refer to my earlier post.

I have had my brakes relined with oversized brake shoes which were then skimmed down to fit the drum by Joe Dunphy a total of 4 times (8 wheel drums) - because I was sick of buying brake shoes over the counter that apparently were nowhere near fitting the Norton brake drum diameter - it was well worth the money then , but is expensive now.

'I have had my brakes relined with oversized brake shoes which were then skimmed down to fit the drum by Joe Dunphy a total of 4 times (8 wheel drums) - because I was sick of buying brake shoes over the counter that apparently were nowhere near fitting the Norton brake drum diameter - it was well worth the money then , but is expensive now."
I do that to ALL my brakes I sell. Ferodo are the worst for undersize shoes.

Bernhard said:

Re; “Discrepancies do not wear in quickly! You just end up with less than optimum braking”

The is a reason for this, that even AFTER you have adjusted the 2ls rods, the shoes were not skimmed down on a mandrel in the first place to the EXACT diameter of the brake drum, as I wrote in my first post on here. Believe me this is IMO the only way to get maximum performance from a drum brake that has no eccentric adjusters.

Re; “been sanded for its full length. Then back it off, adjust the other shoe so it hits first and sand it for its full length.” Refer to my earlier post.

I have had my brakes relined with oversized brake shoes which were then skimmed down to fit the drum by Joe Dunphy a total of 4 times (8 wheel drums) - because I was sick of buying brake shoes over the counter that apparently were nowhere near fitting the Norton brake drum diameter - it was well worth the money then , but is expensive now.

Click to expand...

There are two points here- the 'fit' of the linings to the drum and the adjustment of the TLS tie rod.

There are two points here- the 'fit' of the linings to the drum and the adjustment of the TLS tie rod.QUOTE;

Not to state the obvious here, that is exactly the point I was making!

If you have put emery cloth/ sandpaper between the shoes and the drum you will have some adjustment to take up, I find it far, far better to skim the shoes, failing that, space the shoes out to just under the brake drum diameter, and fit to the bike and wear it away in normal riding, taking up the adjustment as you ride along.