Why ATE style brakes?

[fredintoon]

Alan B just posted that Euro Specials have forward-mounted wheels and "normal" calipers instead of the ATE style calipers on North American Specials.
I'd never seen an ATE style caliper until I got my XS11SG (it was in sad shape) and in unjamming the locked on brakes I found that some clown of a PO had (as I thought) ground the pads tapered. Got new pads and WTF? They are SUPPOSED to be like that??? Seems to me that any braking system that needs tapered pads has to have been designed by an imbecile.
Later I found that Beemers, (the guys that have 9 parts in the entire engine and 142 in the twistgrip) used to have ATE calipers. So why'd Yamaha copy the fools? Does anybody know?
Fred Hill, S'toon.

[AlanB]

Hi Fred,

All the specials I have seen have the "pivoting" calipers. The Euro SPORT has the leading axle forks and conventional calipers.

As far as I know, the Sport (5K7) model did not ever come to the States; Try looking at the European sites for info.

AlanB

[fredintoon]

OK then, SPORT

Hi Alan B,
yes, your original post did say "Sport", not "Special". That the Euro only 5K7 had a forward axle with conventional calipers means that Yamaha did have the parts to fit that layout on the Special. So my question remains; why the stupid swivelly calipers?
Fred Hill, S'toon.

[AlanB]

Hi Fred,

I have been told that most of the reasons for the japs using weird brakes was to do with Lockheed and Girling holding patents on most of the designs which work, so rather than pay the bills, they designed their way round the patents!

I don't know whether that is true, but it would explain a lot about Japanese brake calipers!

Earlier brakes (RD250/350 A+B, early XS650) had "conventional" opposed twin-piston calipers which worked very well; although pads and disc materials were not good! then in the 80's they moved to the swinging/sliding types, when they obviously knew how to make the good stuff, 'cos they did it in the 70's!

AlanB

[prometheus578]

"Not that I know..."

How about...
The beveled pads give a progressive braking effect.
How about...
The beveled face gives more brake pad surface.
How about...
I really don't know.

[HobbyMan]

How about noise? Why do people put shims in STD brake pads?

[prometheus578]

It stops the high speed vibration/chatter when the brakes are applied. Bevelled pads, were thought to eliminate that, by one edge striking first before the full pad engaged. at least that's the story I was told. (and until I know better, that's the story I tell)

[DeanR]

What does ATE calipers stand for?

[fredintoon]

what's it mean?

Hi Laxdad, Prometheus,
I dunno what the initials mean, I called 'em "those effin' stupid swivelly calipers" until someone told me they were knockoffs of BMW's ATE calipers.
Anti-chatter? dunno about that either; the noise my brakes make in an emergency is drowned out by my screaming in fear.
Seems to me that those pads can only wear on the thick edge or they'd be down to the metal in 100 miles or less and that's bad design.
Fred Hill, S'toon.

[Crazcnuk]

If I remember correctly, the reason for the tapered pads was that these types of calipers try and use servo action to apply additional pressure on the rotors.


All drum brakes, since the 60's, are servo acting, meaning that one edge of the shoe hits the drum first, and the rotational torque actually pulls the shoe into the drum. this allows far more braking pressure than one can apply mechanically using the brake pedal.

The fact that disc brakes didin't use this mechanical advantage was one of the early disc brakes shortfalls.

That is why they taper the pads. The thin part, that touches first, gets the least amount of pad pressure on the rotor, and wears the least. As you get along the pad, more and more force is applied and thus more wear.

These pads are worn out when they are pretty much flat across.

[prometheus578]

Thanks. Crazcnuk.

[jimboreeno]

That is the way bicycle brakes are setup. The brake pads are at a slight angle so the toe hits first and draws the pad in just as Crazcnuk explained. On a bicycle the camber is adjustable and doing so is one way to eliminate braking vibration and keep them from screaming as well.

[fredintoon]

Thin edges firts?

Crazcnuk sez:-

That is why they taper the pads. The thin part, that touches first, gets the least amount of pad pressure on the rotor, and wears the least. As you get along the pad, more and more force is applied and thus more wear.

Oh Gawd, it gets worse. Are you saying that the thin edges of both pads in each caliper lead the disk, that they are both at the rear of the caliper?
I swear I installed the bastards one thin edge & one thick edge so at least the slot between them was parallel. Put a few thousand K on the bike since and the brakes seem to work OK.
Help!
Fred Hill, S'toon.

[TopCatGr58]

Relax Fred!

Hey Fred,

You did it correct. The thin edges do not meet, but are thick to thin! They are paired that way in the package as well.
T.C.

[fredintoon]

So far, so good, but - - -

Hi Topcat,
thanks for that comforting thought but is it possible that Mr Stupid could still have gotten it backwards?
Should the thick edge of the outer pad be towards the front of the caliper or towards the rear?
Fred Hill, S'toon.