Author Topic: Norton twin leading shoe front brake.  (Read 210 times)

Offline Grunt

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Norton twin leading shoe front brake.
« on: December 19, 2019, 02:05:12 PM »
I see from Andover Nortonís websites parts list for the twin leading Norton brake that the blanking plates for the air intake and outlets appear to be a standard part, has anyone any idea why Norton would make a brake plate with these features only to blank them off.

 From memory (The bikes been in the back of a shed for 30 years) this is the worst front brake Iíve ever known, it suffered from extreme keenness when damp and extreme fade when hot. I removed the blanking plates when the bike was in use which had no effect on the braking, so I assumed that it was the friction material that was at fault. Has anyone bought new shoes recently and if they are any good where from.

Iím also replacing the wheel bearings, there is a washer in the right hand housing that has been Ďcrimpedí in place. I use the word crimped, it looks more like the housing has been bashed with a blunt chisel. This looks like a factory bodge rather than a shed bodge. Iím assuming the right hand bearing is removed from the right hand side and these Ďcrimpsí have to be ground away first.

Thanks in anticipation,

Offline iansoady

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Re: Norton twin leading shoe front brake.
« Reply #1 on: December 19, 2019, 03:12:31 PM »
With regard to the washer: this doesn't actually hold the bearing in, just the felt seal IIRC. Once you've removed the bearing retainer on the other side you can waggle the central spacing tube over to one side which then allows you to drive one bearing out via the inner race. This doesn't do the bearing an awful lot of good so best to replace. Then the spacer tube will drop out and you can drive the opposite side bearing out - again via the inner race.

I always use 2RS type bearings rather than rely on felt seals.

As far as the brake goes, sounds as though it's the linings as these brakes were decent although not brilliant. You must get rid of any slop in the cam spindles and make sure that both shoes touch the drum at exactly the same time. I have my brakes relined by Villiers Services in Netherton and they always seem to do a good job. As far as blanking off goes, I imagine you only need the vents for racing and for road use it would be better to keep the rain, spiders etc out.
Ian
1952 Norton ES2
1982 Moto Guzzi V50

Offline Grunt

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Re: Norton twin leading shoe front brake.
« Reply #2 on: December 19, 2019, 05:44:47 PM »
Thanks for the reply Ian.

I was going to replace the bearings with sealed bearings, does that make the washer surplus to requirements? Iím sure it will all become obvious when I get it apart but it would be good to know beforehand. Iím also assuming by looking at the Andover Norton parts drawing and your comment about moving it to one side that the central spacer tube isnít strong enough to be used as a drift to drive the first bearing out.

Regardless of the friction material the actual shoes have been round the block a bit and I would like to replace them. Iíll probably get some from Andover Norton unless someone suggests otherwise.

Do you know if there is a maximum diameter for the drum. Mine isnít too bad and a rub round with emery cloth would probably be good enough but it would be nice to know if I could give it a skim.
« Last Edit: December 19, 2019, 05:52:59 PM by Grunt »

Offline L.A.B.

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Re: Norton twin leading shoe front brake.
« Reply #3 on: December 20, 2019, 10:14:29 AM »
Iím also replacing the wheel bearings, there is a washer in the right hand housing that has been Ďcrimpedí in place. I use the word crimped, it looks more like the housing has been bashed with a blunt chisel. This looks like a factory bodge rather than a shed bodge. Iím assuming the right hand bearing is removed from the right hand side and these Ďcrimpsí have to be ground away first.


http://britmoto.com/manuals/Manuals/750_man.pdf
Section H9.

A stiffening kit was fitted to later Commando front drum brakes.

The kit is available from Andover Norton, RGM Motors, etc.:
https://andover-norton.co.uk/en/shop-details/16081
https://www.rgmnorton.co.uk/buy/twin-leader-stiffening-kit-not-for-rgm-twin-leader-commando_2462.htm

Not a personal recommendation (as I don't have the drum brake on my Commando) but RGM's MZ gold shoes are supposed to be an improvement.
https://www.rgmnorton.co.uk/buy/rgm-front-brake-shoes-mz-gold-for-2ls-twin-leading-shoe-high-friction_2441.htm
« Last Edit: December 20, 2019, 10:17:12 AM by L.A.B. »
L.A.B.

Offline iansoady

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Re: Norton twin leading shoe front brake.
« Reply #4 on: December 20, 2019, 11:00:28 AM »
Iím also assuming by looking at the Andover Norton parts drawing and your comment about moving it to one side that the central spacer tube isnít strong enough to be used as a drift to drive the first bearing out.

It's the same ID as the bearings so you can't really use it as a drift as there's nothing to get hold of. Once one bearing has moves a bit the tube becomes free so you can get at the further bearing easily enough.

I'd recommend getting hold of a decent workshop manual - the "official" Norton Villiers one if it's a Commando.
Ian
1952 Norton ES2
1982 Moto Guzzi V50

Offline L.A.B.

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Re: Norton twin leading shoe front brake.
« Reply #5 on: December 20, 2019, 11:57:49 AM »
Iím also assuming by looking at the Andover Norton parts drawing and your comment about moving it to one side that the central spacer tube isnít strong enough to be used as a drift to drive the first bearing out.

It's the same ID as the bearings so you can't really use it as a drift as there's nothing to get hold of. Once one bearing has moves a bit the tube becomes free so you can get at the further bearing easily enough.

I'd recommend getting hold of a decent workshop manual - the "official" Norton Villiers one if it's a Commando.

The procedure for removing the drum front wheel bearings is given in section H9 of the factory manual where the spacer tube is intended to be used (along with the wheel spindle) to drive out both bearings.

I don't know if the rest of the bike (assuming there is one) is a Commando or not in which case getting hold of a hard copy manual would be something of a waste of money and only contain the same information as the online manual in the link I've posted.   
L.A.B.

Offline Grunt

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Re: Norton twin leading shoe front brake.
« Reply #6 on: December 20, 2019, 12:25:58 PM »
Thanks for the replies.

The only bit of the bike thatís Commando is the front brake and forks (I donít foresee any trouble with them). The rest is Featherbed, Rocket Three and conical hub.

Thanks for the manual link I did look for one but my googling skills arenít that good.

I was aware of the stiffening kit but didnít know it was factory fitted, I was thinking along the lines of it being something invented for people to spend their money on.