The curious case of the Atom 4 brakes

[reg]

These use/accept a thicker pad than the oem caliper?

Yes, they’re 18mm so you get a good benefit there as well.

[robfitz]

Looking forward to seeing what you think.

Pity CM is so far away from Bristol.

[reg]

I’ll be back in a few days, likely ready for the snow, but as soon as it clears up I’ll be out. Have a track day booked in March.

[plip1953]

These use/accept a thicker pad than the oem caliper?

Yes, 18mm v 14mm

[reg]

Pictures just in. Looks fantastic!

[robfitz]

Smart. Are you going to Bedford on Mar 20?

[abcoro]

Pictures just in. Looks fantastic!

Looks nice! Not sure about the rattle springs though...

Very curious about your experiences with this upgrade on track!

Cheers,
abel.

[reg]

Looks nice! Not sure about the rattle springs though...

Yes, it's an easy thing to remove, let's see how they work out. Nice to have the option.

[plip1953]

Looks nice! Not sure about the rattle springs though...

Very curious about your experiences with this upgrade on track!

Cheers,
abel.

Do the anti-rattle spring go over the sleeving pieces rather than as substitutes? I'm thinking in terms of overall caliper rigidity.

But in overall terms I think they'll work really well. And with the added advantage of most likely being able to run identical master cylinder sizes front and rear.

[Monza]

Very nice calipers
Did you have to change the stays or anything else or is it direct fitting ?

[plip1953]

Very nice calipers
Did you have to change the stays or anything else or is it direct fitting ?

New caliper brackets are needed.

[Monza]

I read that these beautifull calipers are made for 315 mm diameter discs minimum, but the AP discs are only 288 mm. Are the pads every where in contact with the disc ? or perhaps not on the pads exterior angles ?

[plip1953]

I read that these beautifull calipers are made for 315 mm diameter discs minimum, but the AP discs are only 288 mm. Are the pads every where in contact with the disc ? or perhaps not on the pads exterior angles ?

Fair point, but I've seen vids of the pads against disc fitment and it was spot on. Hopefully Ben Corten-Miller will see these posts and chip in.

[Corten-Miller]

I read that these beautifull calipers are made for 315 mm diameter discs minimum, but the AP discs are only 288 mm. Are the pads every where in contact with the disc ? or perhaps not on the pads exterior angles ?

The pad has the full contact area of the disc with zero overhang, the radial depth of the pad aligns correctly with the backing plate and brake bell assembly clearance. The 315mm manufacturer measurement is a generic measurement as they don’t know pad radial depths being used and the measurement is more focused towards disc sizing you could potentially run. These same calipers are used on our floating brake bells 295mm but the brackets have been calculated that you still get the full disc coverage.

[Charlie]

Are these not the 9444 AP 5000R pro calliper suitable for 13” wheels and therefore 280mm discs as the other calliper 9440 are for 28mm thick discs when the 9444 take a range of thicknesses including standard Ariel size of 24mm I believe.

https://apracing.com/race-car/brake-cal ... s-13-wheel



https://apracing.com/race-car/brake-cal ... iston-area