[Ferrari Fissatore]

well...i'm not convinced.....i'll double check.....but i'm usually right about my car...never the less they are constantly moving up and down on a smoothish road...that's when you get the rattles...one thing for sure, the main springs are doing bugger all! they're 1300-1800lb+!! so all the small movements you get in a car while driving along a normal road extends and compresses the keeper. and every time it compresses, it goes clunk. hence, one spring, no more rattles.

Ok, a smooth road produces no suspension movement if you drive straight and don't brake or accelerate. But yeah, there are usually some small bumps.

A 1300 lb spring is compressed about 1/2" to 2/3" at static ride height with a corner weight of ~660 lbs... It is compressed further as you drive, so they're NOT doing bugger all.

The noise you hear is the transition..... As you hit bumps/undulations, it's possible you FIRST go into DROOP... THEN you go into bump... this can extend enough to un bind the keeper... and then you may hear a noise as it re binds.

Usually though, the noise is the collar that's separating the main and keeper springs, hitting the chassis.

To test for this, a quick shock adjustment usually makes a big difference, as you can delay the droop by increasing rebound.

[Aircon]

Ok, a smooth road produces no suspension movement if you drive straight and don't brake or accelerate. But yeah, there are usually some small bumps.

The noise you hear is the transition..... As you hit bumps/undulations, it's possible you FIRST go into DROOP... THEN you go into bump... this can extend enough to un bind the keeper... and then you may hear a noise as it re binds.

i'm pretty sure that's what i said.

so back to the topic, single springs got rid of that noise for me, and i've never had pad rattle. would be interesting to know why there's that difference with the cars.

[carl888]

While crusing along a dead smooth road (yes, there are some), you can hear the brake pads chatter... very light pressure on the pedal stops it instantly. it's very easy to diagnose.

That's bizarre, surely seal rollback stops the pad chatter? 

[Aircon]

That's bizarre, surely seal rollback stops the pad chatter? 

can't you read? a challenge has no seals!

[carl888]

can't you read? a challenge has no seals!

Really, so there are no seals between the piston and the bore?

I'd check the parts book if I were you.

[Aircon]

or your calipers are so dirty (no dust seals) that the pistons don't retract properly and are binding/dragging.

if you jack it up, do the wheels spin completely freely?

The pads are about 0.5-0.8 mm smaller than the slot in the caliper, and there are no anti rattle fitting as standard.

there you go...no DUST seals.

[carl888]

there you go...no DUST seals.

The dust seals do not determine seal rollback and I never meantioned them as performing that function.  The dust seals only keep out dust and have no rollback function.  The rollback is determined by the very slight taper in the seal channel in the caliper bore.  Now go and check your parts book like I said last time!

[Aircon]

The dust seals do not determine seal rollback and I never meantioned them as performing that function.  The dust seals only keep out dust and have no rollback function.  The rollback is determined by the very slight taper in the seal channel in the caliper bore.  Now go and check your parts book like I said last time!

tell phil to check! he's the one who said the pads rattle. they never have on my car.

[carl888]

tell phil to check! he's the one who said the pads rattle. they never have on my car.

Aha, so you founds the parts book, good boy 

[Aircon]

Aha, so you founds the parts book, good boy 

i don't have a parts book for any cars.