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BRAKES WHAT'S NORMAL
#11
It occurs to me that as new people join the A7 fraternity, not all may be aware that locking the rear wheels at speed is a very effective way of spinning the car. Great fun in a snowy car park, potentially catastrophic on a busy road. Just thought somebody should mention this!
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#12
Thank you Chris for posting that. You are so right. Front rear brake balance should always favour the front.
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#13
Speed?

I don't have speed!


Seriously, though, I have the brakes uncoupled at present, because the car is (relatively) new to me, and I have never driven a Seven with coupled brakes.

So I can tell by feel what exactly is happening at the front and the rear, separately.

Only when I am sure everything is working as it should will I try coupling, and if I don't like it, go back to what I am used to,


Simon
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#14
(21-01-2019, 09:31 PM)Bob Kneale Wrote: The condition of the brake lever bushes is important. Too worn, and they introduce really unacceptable free play. I found replacing these transformed the braking effectiveness.

Bushes are readily available via cherished suppliers Smile

I'm planning to replace my brake drums with the Tony Betts cast iron versions as my pressed examples are so badly oval they can induce motion sickness on long descents.

Can't find an appropriate emoticon (need a green one!).

Bob
Hi Bob,

Hope you wasn't after girling brake drums?

I might as well let people know, the casting company we were useing for cast iron. Has now gone bankrupt. Probably because they were half price we could get anywere else.

The cheif foundryman tried to make sure everyone got there patterns back.

We got everything apart from GIRLING BRAKE DRUMS.

The sad result of all this is due to there being very small profits in these parts, it's unlikely to be worth producing another pattern. The last one cost use £1,000 for a full pattern 15 years ago.

on top of this, the extra we are likely to have to pay another foundry for casting, may make the pre-girling drums unviable to produce in the future. ( I don't think people will pay what it costs to make them).

Now don't all rush  Big Grin But I have 40 of the pre-girling cast iron drums on the shelf. The price is £90 each to cover the fact that we had 10 from this batch that have porosity, so I can't sell to public.

I will look to see what future costs will be, but at the moment I fear the future of new brake drums is not good.

Sorry about the bad news, Tony.
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#15
Old road tests were very non critical especially of favoured Brit makes.  The Motor Nov 1931 on the first lwb Seven (with coupled brakes) “The brakes are adequate when the car is driven carefully and have the merit of being very safe; they are almost impossible to lock on even on slippery surfaces. To get reasonably short pulling up distances we found it necessary to apply the foot and handbrake simultaneously.”
Nevertheless took 66 feet from 30 mph, 46%, less than current legal minimum (although, until quite recently, not uncommon for laden trucks and buses.)
(I trust the term “we” does not mean the passenger assisted!)  it is surprising what force the flimsy looking handbrake tolerates. When it is claimed that Sevens were made of the best materials it is true!
 
On a few occasions when the traffic stream stopped suddenly my coupled brake RP locked rear wheels in the wet at terminal velocity. With 200 lb on the pedal the retardation was not evident and it took a few milliseconds to realise why the world was suddenly quiet and peaceful.
(With ideal lining materials better results are apparently achieved today)
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#16
An immediate piece of advice from experience is to get a set of cast iron drums from Tony Betts.

Coupled vs uncoupled brakes on a Seven is the sort of thing being chatted about in a pub car park in Ludlow on Sunday morning. For trialling, being able to operate rear wheel brakes separately is very desirable, making reversing down a not quite climbed hill significantly less "character forming". Any trialling Seven I've encountered has either kept uncoupled or if a later car, had the brakes de-coupled. Some other cable braked cars originally built as coupled have had separate rear brake application added by owners. Those of us daft enough to trial 2CVs have a big challenge, with handbrake operating on the front wheels of a front wheel drive car. Cadence braking in reverse is a necessary skill.

How did the other forum contributors get on trialling on the Clee Hills on Sunday? Were we alone in finding the green lane and track sections between hills, particularly on the Long Mynd, badly chewed up probably by the off road Landies? I enjoyed sledging Sunday, with the sump guard sliding down the middle between deep ruts, steering provided by the sides of the wheels pushed by the ruts as the wheels did not touch the ground. How did Sevens without sump guards get on?

Sorry but I was unable to get useable snaps of the competing Sevens for the forum, the mist was so thick and the light levels so gloomy that even a modern camera couldn't cope.
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#17
(23-01-2019, 07:52 PM)Tony Betts Wrote:
(21-01-2019, 09:31 PM)Bob Kneale Wrote: The condition of the brake lever bushes is important. Too worn, and they introduce really unacceptable free play. I found replacing these transformed the braking effectiveness.

Bushes are readily available via cherished suppliers Smile

I'm planning to replace my brake drums with the Tony Betts cast iron versions as my pressed examples are so badly oval they can induce motion sickness on long descents.

Can't find an appropriate emoticon (need a green one!).

Bob
Hi Bob,

Hope you wasn't after girling brake drums?

I might as well let people know, the casting company we were useing for cast iron. Has now gone bankrupt. Probably because they were half price we could get anywere else.

The cheif foundryman tried to make sure everyone got there patterns back.

We got everything apart from GIRLING BRAKE DRUMS.

The sad result of all this is due to there being very small profits in these parts, it's unlikely to be worth producing another pattern. The last one cost use £1,000 for a full pattern 15 years ago.

on top of this, the extra we are likely to have to pay another foundry for casting, may make the pre-girling drums unviable to produce in the future. ( I don't think people will pay what it costs to make them).

Now don't all rush  Big Grin But I have 40 of the pre-girling cast iron drums on the shelf. The price is £90 each to cover the fact that we had 10 from this batch that have porosity, so I can't sell to public.

I will look to see what future costs will be, but at the moment I fear the future of new brake drums is not good.

Sorry about the bad news, Tony.

That's a great shame Tony. I've been promising myself a set of Girling drums for a while - serves me right for not doing something about it!

Silly question, but can't you use the same pattern again?

Peter.
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#18
I realise the cost of labour is crippling but 1,000 quid seems a lot. If provided with exact instructions of what required surely there would be someone within the Clubs able to oblige more reasonably. Did the pattern include  a dedicated casting box?

As a matter of interest does anyone know if original brake drums were plain or malleable cast iron, meehanite or alloy, and what are replacements? Ductile iron?

Plain iron seems weak altho many of the reskimmed steel drums cannot exactly be strong!
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#19
(23-01-2019, 11:19 PM)KPeter Naulls Wrote:
(23-01-2019, 07:52 PM)Tony Betts Wrote:
(21-01-2019, 09:31 PM)Bob Kneale Wrote: The condition of the brake lever bushes is important. Too worn, and they introduce really unacceptable free play. I found replacing these transformed the braking effectiveness.

Bushes are readily available via cherished suppliers Smile

I'm planning to replace my brake drums with the Tony Betts cast iron versions as my pressed examples are so badly oval they can induce motion sickness on long descents.

Can't find an appropriate emoticon (need a green one!).

Bob
Hi Bob,

Hope you wasn't after girling brake drums?

I might as well let people know, the casting company we were useing for cast iron. Has now gone bankrupt. Probably because they were half price we could get anywere else.

The cheif foundryman tried to make sure everyone got there patterns back.

We got everything apart from GIRLING BRAKE DRUMS.

The sad result of all this is due to there being very small profits in these parts, it's unlikely to be worth producing another pattern. The last one cost use £1,000 for a full pattern 15 years ago.

on top of this, the extra we are likely to have to pay another foundry for casting, may make the pre-girling drums unviable to produce in the future. ( I don't think people will pay what it costs to make them).

Now don't all rush  Big Grin But I have 40 of the pre-girling cast iron drums on the shelf. The price is £90 each to cover the fact that we had 10 from this batch that have porosity, so I can't sell to public.

I will look to see what future costs will be, but at the moment I fear the future of new brake drums is not good.

Sorry about the bad news, Tony.

That's a great shame Tony. I've been promising myself a set of Girling drums for a while - serves me right for not doing something about it!

Silly question, but can't you use the same pattern again?

Peter.
Sorry Peter,

I always thought the cost of machineing would take these of the market.

Its not a matter of reusing the pattern, the patterns for girling drums. Have been LOST LOST at the foundry.

So I no longer have a pattern for girling drums.

I'd guess it will cost around £1,200 for another pattern. So if I added £12 a drum to the next batch of a 100. Last years price was £70 each, so that would make them £82 each. If I have to add anything because the next foundry charges more. That could push them over £100 each.

I just don't see austin 7 people paying it, they would rather take there chances with poor brakes.

I DO STILL have the pattern for 1926 to 1935 drums, but the rise in price of castings from the next foundry make make them unviable. I can't put 100 drums on the shelf when only two people are prepared to pay more to get good brakes on there cars.

Tony.
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#20
Tony, I have a french friend who works for an international steel/iron founders with factories in India and as well as elsewhere. I will ask him how much for a new pattern and a batch of 100 castings. Do you sell them pre-machined or unfettled?
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