H: Hubs, Wheels and Tyres Eight inch brake ?

[Bill Thomas]

A great period picture. (Just like a modern Formula1 pit stop. )
I can't see anything like that happening nowadays with Health and Safety ruling the roost.
Cadwell Goose circuit was very challenging for the brakes as you were on full fade downhill into Mansfield and so were lucky to have much brake when you got to the hairpin shortly after.

I was trying to remember the name of that bend, Was it not Mansfield at the top, Then the long steep down hill, I had the brakes on at the top !!,Then the sharp bend at the bottom That's why I went for a disc.
But I went back to standard brakes when I built the L/ning rep, 1980, I did more racing and rode much better I think, Even though the L/ning was nowhere near as fast as my Special.
If you make the photo bigger, You can see the 4 ? type brake we made.
Lots of Fun, Bill.

 

[Chris Launders]

Gooseneck at the top, Mansfield is the sharp left bend at the bottom.

 

[john998]

Hello, early 70s the club Cadwell meeting had 50 lap races, relay races, ,
and something called the Cadwell 100. I think the last was 75 laps.
I have fond memories of a very wet 75 lap event.
With my brakes after 3 laps if you missed a down change you needed the slip road. John.

 

[Bill Thomas]

Hello, early 70s the club Cadwell meeting had 50 lap races, relay races, ,
and something called the Cadwell 100. I think the last was 75 laps.
I have fond memories of a very wet 75 lap event.
With my brakes after 3 laps if you missed a down change you needed the slip road. John.

Hello, early 70s the club Cadwell meeting had 50 lap races, relay races, ,
and something called the Cadwell 100. I think the last was 75 laps.
I have fond memories of a very wet 75 lap event.
With my brakes after 3 laps if you missed a down change you needed the slip road. John.

Ron just sent me a DVD of some of our old " Fun and Games" Silent Not good filming but you get the idea,
I think there is some of you in Bill Hancock's sidecar, Can't think it was all that time ago.
All The Best, Bill.

 

[vibrac]

All cadwell is ruined now with a chicane placed before the hairpin (or where the hairpin is on the club circuit but now on main circuit its the bend towards the mountain) why oh why do track changes employed to slow crutch rockets have to apply to pre seventies historic races it's only a line of bollards
it is indeed a load of bollards.

 

[BigEd]

I was trying to remember the name of that bend, Was it not Mansfield at the top, Then the long steep down hill, I had the brakes on at the top !!,Then the sharp bend at the bottom That's why I went for a disc.
But I went back to standard brakes when I built the L/ning rep, 1980, I did more racing and rode much better I think, Even though the L/ning was nowhere near as fast as my Special.
If you make the photo bigger, You can see the 4 ? type brake we made.
Lots of Fun, Bill.

Below is my favourite Cadwell Park photograph. My brother John on my Sunbeam (140), Roger Moss, Scott (115), Mervyn Stratford, Rudge (47). They have just come through the Gooseneck together (I bet that was interesting!) and rushed down the hill into Mansfield left-hander three abreast. I wouldn't like to guess who had the most brake left after this but it wouldn't be John as he didn't have much brake to start with!

 

[Texas John]

Greg,

I have reviewed all of the brake articles written in MPH through the wonderful work of Graham and others on the Database. Thank you to those involved!
<<SNIP>>
I don't believe there is any value in relining stock Vincent brake shoes. I think Trevor is correct and these shoes are junk. They are not hardened correctly. Assuming the replacement shoes are the correct material and hardened properly, that should be the first course of action.

There are lots of linings that are as good or better than AM4. It is just difficult to find this info. I would not get a lining without knowing its coefficient of friction. The Ferodo MZ41 that I believe Martyn is using has a coefficient of friction of .43 cold and .45 hot, which is essentially better than AM4, which goes down to .40 when hot. I am not sure if they have asbestos. I would pass if they did and choose a similar non-asbestos lining.

...and yes, I was trying to improve the brakes this way, much like the Girdraulics. Drum brakes, however, are wildly complex, unlike the Girdraulic!

David

David,

You mentioned "replacement shoes" - are you referring to current VOC Spares stock, or something else?
And a prior post in this thread alluded to some other shoes becoming available, but no details were given.
And a thought about the balance beam - It seems to me that it would equalize ("balance") the force on both sides, i.e. correct for some maladjustment so both sides of the brakes operated at about the same time and with approximately equal force.
And have you found some new brake lining material, better than the "Green Gripper Woven" material you mentioned recently?

 

[vibrac]

I think Goddet makes alloy reinforced 'corrected' shoes the spares company did have a few but they were helishly expensive as supplied to them so I don't think they have any now

 

[hadronuk]

I don’t buy the argument that the standard shoes are insufficiently rigid or that a hardened alloy will give greater rigidity.
Regarding hardness, correct me if I’m wrong, but the Young’s Modulus for all aluminium alloys is in the fairly narrow range of 68.9 to 73.8 GPa and for a given alloy is not altered by hardening. So up to the point where the materials yield point is exceeded, an aluminium alloy components rigidity is largely independent of the type of alloy or it’s hardness. Unless the standard shoes of the correct dimensions are being permanently distorted in use, indicating their yield point has been exceeded, surely hardening is of no benefit?
The mismatch between the dimensions of the standard shoes and backplate will massively increase the stress on the shoe and consequently may permanently distort it. But the answer is to correct this mismatch, which is a major problem even if the shoe is so strengthened that it doesn’t distort.

 

[greg brillus]

There is a possible issue with brake shoes that may or may not be my imagination, but relates to shoes that have had linings bonded on rather than original rivets. In the bonding process the new lining material is glued and clamped to the shoe using a wrap around band and adjustable center bolt arrangements that "Jack the shoes apart" thus holding the linings firmly to the shoe whilst the glue is baked in the oven. I have found on some occasions that the shoes appear to have distorted and twisted, perhaps also due to the heat from the baking process as well ( I am not sure how hot they get) I have seen once the shoes are assembled on the brake plates, that the shoes seem to sit on the cam with the faceplate closer to the inner end of the cam and not central. This must affect the brakes working ability..............I discussed this with my brake man and he now uses less pressure when clamping the linings to the shoes.................I can see how this could be a universal problem that may affect more than just one bike out there. It is also likely to happen because the shoes are very narrow and are quite weak in design. Any thoughts..................???