H: Hubs, Wheels and Tyres Alloy brake plate dimensions Help….

[Cyborg]

Does anyone out there have drawings for the Lightning/Flash pattern brake plates? I need to machine the areas A to F so if I could find out the depth of the axle bore A and it’s height relative to E that would be appreciated. Then I would need the height of B,C,D, and F relative to whatever A is. If no drawings, does anyone have a front plate they would be willing to take measurements from?
Thanks..

 

[bmetcalf]

Does the Obscure Components series have the dimensions?

 

[Cyborg]

Not in the list that I have. I used that info for the tach mount and a couple of the rearset bits that I was missing. Actually there is a better (more original) drawing around somewhere for the tach mount.

Edit… Robert told me where I might get some of the information, so will have a look and see what I come up with.

 

[Bill Thomas]

I would have thought it will be the same as a standard steel plate ?,
A long time ago 1970 ish, I bought Slater Alloy Brake Plates,
Some of us had a lot of trouble, It worked out that the centre hole was wrong,
So the shoes were only touching a third of the drum !,
I made the Huge !! mistake of fitting them the night before a Cadwell Park race day,
Which was a Disaster.
Let me know if you want me to check a steel plate ?.
Cheers Bill.

Also don't stick the Stone Filter on the inside, They fell Off !.

 

[Cyborg]

Well Bill…. always good when someone stops by and points out the obvious.
I fear you are correct, which likely means I shouldn’t be playing with machinery.
That should provide most of the information.
I don’t have enough bits to put together a hub/bearings/axle/drum assembly yet, but the missing pieces are on the way. Once I have that, it all “should“ start to make sense.

With those Slater plates, did you use E80 nuts to hold the whole mess together?
I’m a little confused over that part. IIRC there isn’t a lot of room for the nuts (on the axles) when using steel plates. The alloy plates will take up more real estate.
I have been informed that the Lightning/Flash plates had nuts. So the magnesium alloy axle boss must have been fairy thin. It all has to fit between the fork blades…

Could be that I’m missing something else obvious.

 

[Bill Thomas]

No Nuts Ken,
The alloy plates are Thicker , At the centre hole , So the plates should be just proud of the hollow axle.
I was so upset, Could use other words !,
We tried to turn them into 4 leading shoe = Better, But I made a few mistakes,
Didn't know till after that it was the centre hole, Thought it was everything else !.
So put a disc on and Norton Forks.
Can't remember with the Mag' Plates, But I don't think they had nuts for the same reason,
We not long ago fitted Mag' Plates, To a Twin ,Not mine, So I should know, But, But !.
You should have room for nuts on steel plates, Play with the shims ?.

 

[Bill Thomas]

Ken, Looking at the photo, I think the studs that go through the plate are longer ?.
This is a VOC Spares plate, From 1980 ish,
Because of the thicker bosses ?.

 

[timetraveller]

I could measure up one of the new machined from solid ones but whether they are relevant to your castings I don't know. One thing which should be realised is that the holes in the centre of the original Electron plates was larger that the diameter of the hollow axle. The reason for this was so that upon assembly one could apply the brakes to centre the shoes within the drums before tightening the tommy bar axle. I tried to persuade the manufacturer of the new plates to do this but without success. The disadvantage of this is that upon dissassembly there is a tendency for the whole lot to fall apart and onto the floor. Rather like the original cup and cone head races. One person I know who used the new type brake plates, but with the 8" diameter brakes, machined back the centre thickness of the brake plate and then used a nut to tighten it up. Let me know if you think the measurements of the new plates is of any use to you.

 

[Bill Thomas]

Sorry Ken , The steel plates have built in pivots, Brain fade !,
But the OLD spare parts list , Say no E80 nuts for the Flash and L/ning .

 

[Bill Thomas]

I could measure up one the new machined from solid ones but whether they are relevant to your castings I don't know. One thing which should be realised is that the holes in the centre of the original Electron plates was larger that the diameter of the hollow axle. The reason for this was so that upon assembly one could apply the brakes to centre the shoes within the drums before tightening the tommy bar axle. I tried to persuade the manufacturer of the new plates to do this but without success. The disadvantage of this is that upon dissassembly there is a tendency for the whole lot to fall apart and onto the floor. Rather like the original cup and cone head races. One person I know who used the new type brake plates, but with the 8" diameter brakes, machined back the centre thickness of the brake plate and then used a nut to tighten it up. Let me know if you think the measurements of the new plates is of any use to you.

That idea works well with steel plates, Hold the brake on and make up a thin spanner to tighten E80
After the wheel spindle is nipped, Then tighten proper,
We also have made the centre holes bigger, A Nats !.