Brakes - Fixed disc vs Floating disc ?

[JB_VXR]

Can someone very briefly explain the difference in design and overall difference on the road? Will it improve braking power? Is it only beneficial with regards to heat (i.e. fade)... I'm trying to decide on whether the floating disc upgrade on the XYZ brakes I'm getting is worth it.

Thanks,
Al.

[IanJ]

I believe there is a benefit in unsprung weight in having ally centres - although not sure how much that would show on the road though

[Gnasher]

I believe there is a benefit in unsprung weight in having ally centres - although not sure how much that would show on the road though

That will be the difference between 1 piece and 2 piece discs.

You can get both fixed and floating in 2 piece designs.

Not a clue about how the differences would pan out on the road but I know some bikers that have had big 'tankslappers' whilst riding and this has caused the floating discs to push the pads and pistons back into the calipers a bit, meaning they have to pump them back out at (hopefully in time) for the next corner.

[RDG XX]

floating are the way to go.

They benefit from heat transfer and general improvement.

Also whether you go grooved or drilled will make differrence.

[JB_VXR]

I guess the XYZ disc are groved rather than drilled. I'm not sure heat transfer is gonna be a big issue for me on general fast road use. In fact it sounds like 1 more thing to go wrong :S

[s4rpf]

Single Piston Floating Calipers are the most popular and also least costly to manufacture and service. A floating caliper "floats" or moves in a track in its support so that it can center itself over the rotor. As you apply brake pressure, the hydraulic fluid pushes in two directions. It forces the piston against the inner pad, which in turn pushes against the rotor. It also pushes the caliper in the opposite direction against the outer pad, pressing it against the other side of the rotor. Floating calipers are also available on some vehicles with two pistons mounted on the same side. Two piston floating calipers are found on more expensive cars and can provide an improved braking "feel".

Four Piston Fixed Calipers are mounted rigidly to the support and are not allowed to move. Instead, there are two pistons on each side that press the pads against the rotor. Four piston calipers have a better feel and are more efficient, but are more expensive to produce and cost more to service. This type of caliper is usually found on more expensive luxury and high performance cars.


Thats what google said anyway

[vxrdave]

Single Piston Floating Calipers are the most popular and also least costly to manufacture and service. A floating caliper "floats" or moves in a track in its support so that it can center itself over the rotor. As you apply brake pressure, the hydraulic fluid pushes in two directions. It forces the piston against the inner pad, which in turn pushes against the rotor. It also pushes the caliper in the opposite direction against the outer pad, pressing it against the other side of the rotor. Floating calipers are also available on some vehicles with two pistons mounted on the same side. Two piston floating calipers are found on more expensive cars and can provide an improved braking "feel".

Four Piston Fixed Calipers are mounted rigidly to the support and are not allowed to move. Instead, there are two pistons on each side that press the pads against the rotor. Four piston calipers have a better feel and are more efficient, but are more expensive to produce and cost more to service. This type of caliper is usually found on more expensive luxury and high performance cars.


Thats what google said anyway

Fixed disc vs Floating disc

not calipers

[Drunken Master]

Floating discs with aluminum bells don't put so much heat into the hubs as iron fixed discs. And also less unsprung weight.

Don't get what you mean here "Is it only beneficial with regards to heat (i.e. fade)...

[Cerberus]

wheres Luke H he will answer this for us

[Luke.H]

A solid one piece disc is obviously prone to warping under extreme heat, not so good as generally large diammeter discs are expensive in 1 piece (ie oe form)

A 2 piece floating disc is generally reserved for racing purposes, they allow heat to dissipatate alot better and allow the disc to grow around the bell without warping under extreme heat (OT is generally 250 degrees). However i have floating discs on my car due to my setup. On the road they chatter like f00k going down the road making it sound like something is loose!

A 2 piece (disc and bell) fixed disc is generally a good comprimise for road cars imo. They allow heat transfer and dont chatter due to not having the freeplay of a floating disc.

[Cerberus]

see told ya

[vxr-blacksheep]

just out of interest luke what set up are you running ? as the alcon full floating discs don t chatter at all . This may be down to the fact that on every other fixing of the bell there is a small spring type washer / clip .

[Cerberus]

IIRC correctly he is running BTCC spec AP's

[Luke.H]

just out of interest luke what set up are you running ? as the alcon full floating discs don t chatter at all . This may be down to the fact that on every other fixing of the bell there is a small spring type washer / clip .

Yeah AP get around the chattering with the 'strap drive disc' types.

How much float do the alcons have with the anti rattle plates installed?


I run an AP Toca spec 6 piston calliper with anti knock off springs behind the pistons. 343x32mm discs again Toca spec off touring car. Ferodo ds3000 pads on track. Ds2500 with a set of discs for these pads on the road


Mine chatter as there is a good 1-2mm full travel float on them.

[vxr-blacksheep]

nice must work well out on track , oh and on the road even if people think yours are falling off does the chattering ease off a little when warmed up ?

i did notice on one of the posts you put up with a link to APs web with all the drawings with spec and parts that they run with quite a lot of float .

the alcons extreme kit run with no more than about 1mm laterally ( side to side ) and about 2.5-3 mm availible for growth/expansion .