Brake adjustment

[Curves Junkie]

My ariel has at the front the 'Alcon Big Brake Kit' and at rear the 'Sport Brake Package'.
Both pushrods have the same length. The front master cylinder have 0.7'' and the rear 5/8'' diameter.

Now I want to adjust my brake but I don't understand all in the owner's handbook what to do.



Brake compressed:


Brake depressed:


You see I have no 'hole' in the adjusting shaft for an allen key and no brake bias.

In my mind I must have more brake pressure at rear because the engine and weight is high at rear.
In the first pic I don't understand what meaning e.g. 3/8'' right of centre?
3/8'' = 9.525 mm
But where is the centre?
Where I have to measure the distance 3/8''?

What are you doing to find the correct brake setting for your car?

Thx for help and I will hope you all understand my german-english. 

[phil4]

Ok, for me adjusting the brake bias is easy, as I just twiddle the dial on the dash.  I've got that remote brake bias adjuster.

You asked... how do I set it.  On the more general theme.  I find an unused road, get up to a reasonable speed, stand on the brakes and see which locks up first.  Adjust and repeat, until happy.

Personally I prefer the fronts to lock up marginally before the rears (I think that's what the manual is suggesting too), but by doing the above I can make sure it is marginal.

As to your theory of engine weight over the rear.  I get it, but you've put big brakes on the front for a reason.  It's because as the car stops, the fronts can do more of the braking than the rears.  So surely you'd make more use of that by setting more braking to the front?

Why do the fronts have more effect?  Because the braking will make the rear lighter, in essence rotating the car around the front wheel, so the front gets pushed down, the rear lifts up up... the weight on the rear reduces, and so the braking that can be applied there is a lot less.

Look at motorbikes for an exaggerated version, they've usually a single tiddly brake disk on the rear, and two big ones on the front.

[Curves Junkie]

[quote="phil4"]
Ok, for me adjusting the brake bias is easy, as I just twiddle the dial on the dash.  I've got that remote brake bias adjuster.

You asked... how do I set it.  On the more general theme.  I find an unused road, get up to a reasonable speed, stand on the brakes and see which locks up first.  Adjust and repeat, until happy.[/quote]
OK, but i have no brake bias at the moment because the former owner don't order ist. 
In the future I will made the big brake at the rear and the bias too.

[quote="phil4"]
Personally I prefer the fronts to lock up marginally before the rears (I think that's what the manual is suggesting too), but by doing the above I can make sure it is marginal.

As to your theory of engine weight over the rear.  I get it, but you've put big brakes on the front for a reason.  It's because as the car stops, the fronts can do more of the braking than the rears.  So surely you'd make more use of that by setting more braking to the front?
[/quote]
That's what I want.
The car must lock up the front first because when the rear lock up first I get problems when the street is wet.
But with no bias I have to find the optimal setting before driving and then fiddle the setting while testing drives.
So I want to know what's near to the optimum 1/8, 1/4 or 3/8'' right-of-centre BUT where is the centre. I can't translate it correct - so I don't understand it.
I think right-of-centre is correct way OR is left-of-centre correct??

[smokin]

Hi Curves,

You need to measure inside the pivot sleeve (item 5 in book) on each side to find current position of spherical bearing.

I would start with 3/8" i.e. 65% / 35% toward front cylinder and move toward rear cyclinder when testing until rears lock first, and then move toward fronts a couple of turns.

left or right of centre depends on which cylinder is front/rear. On UK right-hand-drive it is right of centre for front cylinder. The closer the bearing is to the cylinder the more force it receives.

[John Scherrer]

Here's the Tilton installation instructions :-

[Curves Junkie]

[quote="smokin"]
left or right of centre depends on which cylinder is front/rear. On UK right-hand-drive it is right of centre for front cylinder. The closer the bearing is to the cylinder the more force it receives.
[/quote]

Hi @smokin
the last first. You see on my first picture that my master cylinder are in the same order than the UK cars.
Looking from front of the car to the back there is right the cylinder for the clutch, middle front brake and left rear brake.

[quote="smokin"]
You need to measure inside the pivot sleeve (item 5 in book) on each side to find current position of spherical bearing.[/quote]
The only think I can do is measure the difference the right edge (clutch side) of the pivot sleeve to the spherical bearing and this is 1.4 cm. the left side I can't measure because the plastic.
Looking at the pdf from John Scherer (thx for it) my car must have the Part #72-260 installed

[quote="smokin"]
I would start with 3/8" i.e. 65% / 35% toward front cylinder and move toward rear cyclinder when testing until rears lock first, and then move toward fronts a couple of turns.[/quote]
I sounds good but from where to where I have to measure 3/8''?

It's Bullshit when I can't explain what I want to say. 
So I need a lot of time to fiddle the correct brake setting.

[smokin]

Don't worry, your posts are clear

If you can't get access to measure, maybe:

• loosen jam / lock nuts all the way and then turn balance bar clockwise until stops
• then turn anti-clock until stops, counting the turns

Half way is centre 50/50 split. Give it another 10% toward front and road test somewhere safe

[Oli1122]

Why all the fiddling?
Go and order the brake bias adjuster from Demon Tweeks or ISA Racing.

http://www.isa-racing.com/index.php/cat/c293_Waagebalkenzubehoer.html

It is worth every €. When you are used to how the adjustment works with your driving style you are playing a lot with it (due to temperature asphalt and tyres etc.). I would loose my nerves with all the inaccurate adjustment without instant testing while driving.

It is also a big benefit while your driving the smaller brakes on the back. I experienced both, big brakes front, smaller brakes back and bigger brakes all around.
So imho the brake bias adjuster is essential to get out the best brake force possible.

[Curves Junkie]

Don't worry, your posts are clear

LOL, that's fine that you understand my Schwaebisch-English. 
But it's better than the English from my fellow countryman Guenther Oettinger. 

If you can't get access to measure, maybe:
loosen jam / lock nuts all the way and then turn balance bar clockwise until stops
then turn anti-clock until stops, counting the turns
Half way is centre 50/50 split. Give it another 10% toward front and road test somewhere safe

That's the way that I use it for the moment.
I have 18 3/4 turns total. So I have set for the moment 11 turns clockwise to the rear master cylinder.
Tomorrow it seems that the weather will be fine, so I will test it.

Why all the fiddling?
Go and order the brake bias adjuster from Demon Tweeks or ISA Racing.

http://www.isa-racing.com/index.php/cat/c293_Waagebalkenzubehoer.html

It is worth every €. When you are used to how the adjustment works with your driving style you are playing a lot with it (due to temperature asphalt and tyres etc.). I would loose my nerves with all the inaccurate adjustment without instant testing while driving.

Ok, ok I have ordered from isa-racing the 7/16 Zoll UNF now. 
I had a phone call with the German importer Steffen Queck few weeks ago and he told me that it's not a good idea to use the brake bias adjuster when I have the small brake in the rear because this rear brake is to undersized.

It is also a big benefit while your driving the smaller brakes on the back. I experienced both, big brakes front, smaller brakes back and bigger brakes all around.
So imho the brake bias adjuster is essential to get out the best brake force possible.

Which kind of rear brake are you using at the moment?

Do you have a pic where I can see where you fix the cable and see the 'cable way' to cockpit?

[Oli1122]

I had a phone call with the German importer Steffen Queck few weeks ago and he told me that it's not a good idea to use the brake bias adjuster when I have the small brake in the rear because this rear brake is to undersized.

All my opinion here so...
As the Alcon brakes on the front will lock up quite early with the sports brake on the back you have to transfer the brake distribution almost to the farthest point backwards. The sports brake is not especially undersized for a car that light but in comparrision with the front and rear Alcon option it definitely feels like it is. 

Which kind of rear brake are you using at the moment?

Alcons on all four corners. But in my case (AA2) it was joy expensive to retrofit it with other uprights and the additional mechanical handbrake calipers. 

Do you have a pic where I can see where you fix the cable and see the 'cable way' to cockpit?

I own an AA2 and as I read the AA3 is a bit different. Better ask K20a2 (even in German) and take a look at his topic.

http://www.atomclub.com/forum/index.php/topic,15537.msg269134.html#msg269134

[Curves Junkie]

I had a phone call with the German importer Steffen Queck few weeks ago and he told me that it's not a good idea to use the brake bias adjuster when I have the small brake in the rear because this rear brake is to undersized.

All my opinion here so...
As the Alcon brakes on the front will lock up quite early with the sports brake on the back you have to transfer the brake distribution almost to the farthest point backwards. The sports brake is not especially undersized for a car that light but in comparrision with the front and rear Alcon option it definitely feels like it is. 

Which kind of rear brake are you using at the moment?

Alcons on all four corners. But in my case (AA2) it was joy expensive to retrofit it with other uprights and the additional mechanical handbrake calipers. 

Sorry verstehe nicht was du mir geschrieben hast. Konnte es nicht übersetzen und verstehen.
Sorry can't understand what you wrote.

[John Scherrer]

Some pictures of the balance bar with the adjuster :-

[John Scherrer]

and ..

[Curves Junkie]

[quote="John Scherrer"]
Some pictures of the balance bar with the adjuster :-
[/quote]
Thx, John for the pictures.

Can I see it correct that the bias is mounted at the adjusting shaft next to the rear master cylinder?

[John Scherrer]

Yes, here's a picture taken from outside the car (car is Right Hand Drive).

In your 1st post, you say :-

"My ariel has at the front the 'Alcon Big Brake Kit' and at rear the 'Sport Brake Package'.
Both pushrods have the same length. The front master cylinder have 5/8'' and the rear 0.7'' diameter."

I think this may be incorrect, the rear is usually 5/8", the front 0.7" ?
If you have Alcons at the rear, the 5/8 is usually replaced by another 0.7.

The clutch is also 0.7" ..