SIX PISON FRONT BRAKE CALIPERS......

[SILVERGOAT]

I am in the process of fitting YZF600 front forks and wheel onto an 89 FJ1200. Has any one experimented with six piston front brake calipers with these or the stock forks? I have seen a bike like the one I got the forks off of with six piston calipers, but can't tell what they are from. Kawasaki 636 came with six piston set up and so did some GSX-Rs. Any info as far as mountng spacing is greatly appreciated.

[mz_rider]

I've go two FJs, one with blue spots and one with YZF750 six pot calipers. I know there are a lot of variables (pads. hoses etc) but the six pots are better - huge amounts of power & feel. They are a straight bolt on to standard forks.

Stuart

[MyFirstNameIsPaul]

Personally, I think its all in the rider's mind.  Nobody in World Superbike complains about 4 piston calipers and in MotoGP they can use whatever they want, and they use 4 piston calipers, even in their wet setup with steel discs.

[andyb]

It's a common mod to go from the B3-4 to B1-2 brakes on a early ZX9R..... means going from 6 pots to four--So it isn't always better to have more.

I don't see any reason why it really matters, in either case you've got enough brakes to lift the rear off the ground, and that's pretty adequate for me...

[Dan Filetti]

It was Frank Moore that recently said, [and I agreed with] that there is a big difference between 'feel' and 'power'.  Most bike have enough 'power' to lock the front right up.  What your looking for is 'feel' or a the ability to precisely control the progression up to [but not beyond] the point of wheel-lock.  If six pots give you that, go for it, if not, there are great 4 pot setups that provide lots of 'feel'.

Dan

[racerman_27410]

modern brakes provide that perfect "feel" in spades now ...the fact that mere mortal riders can easily get enough weight transfer to loft the rear without locking the front is proof that the manufacturers have concluded their experiments and determined that 4 pistons of certain sizes in conjunction with having the least amount of swept area (pad size/rotor diameter) possible will provide all the feel and power one could ever require the brakes to possess.

i think the 6 piston setups were just some ideas that happened to make it to market but in the end provied no real benefit.

Kookaloo! (until ya HAVE to slow down)

Frank

[higbonzo]

i think the 6 piston setups were just some ideas that happened to make it to market but in the end provied no real benefit.

Kookaloo! (until ya HAVE to slow down)

Frank

So why do the 2010 R1's have six pots on the front?

Later......

[rktmanfj]

modern brakes provide that perfect "feel" in spades now ...the fact that mere mortal riders can easily get enough weight transfer to loft the rear without locking the front is proof that the manufacturers have concluded their experiments and determined that 4 pistons of certain sizes in conjunction with having the least amount of swept area (pad size/rotor diameter) possible will provide all the feel and power one could ever require the brakes to possess.

i think the 6 piston setups were just some ideas that happened to make it to market but in the end provied no real benefit.

Kookaloo! (until ya HAVE to slow down)

Frank

I have no experience with the YZF750 six pots on an FJ, but on the YZF750 they were VERY nice...     

Randy T
Indy

[tqmx1]

The other nice thing about running the 6pots is you are able to stay with the stock 5/8" master cylinder the combo matches up nice

[racerman_27410]

So why do the 2010 R1's have six pots on the front?

Later......

that's a damn good question....  

here is an interesting article i found on brake calipers....

http://www.superstreetbike.com/howtos/0906_sbkp_brake_calipers_explained/index.html

so to me it looks like if you want a smaller rotor (310mm on the 6 piston models = less rotational force/less unsprung weight) you would need 6 pistons working on it to achieve the same braking force as a larger rotor (previous version 320mm) would have using 4 piston calipers

so it looks like they switched to 6 piston calipers in order to have smaller diameter rotors which will improve transitional handling by decreasing unsprung weight.

howzat?

KOokaloo!

[Dan Filetti]

Huh?  So a 10mm ring of rotor weighs MORE than bigger calipers and an extra pot?  Seems somewhat improbable to me.  I rather think it has something to do with more surface area or some such.  But that just a casual observation.

Dan

[racerman_27410]

Huh?  So a 10mm ring of rotor weighs MORE than bigger calipers and an extra pot?  Seems somewhat improbable to me.  I rather think it has something to do with more surface area or some such.  But that just a casual observation.

Dan

well....that 10mm is STEEL and it rotates with the wheel......i can also see where six smaller pistons could weigh less than 4 large ones..........and fit in almost the same amount of space......... if it had to do with more surface area then why reduce the diameter of the rotors? why not keep the 320mm rotors and add the 6 piston calipers to that?





Kookaloo!

[higbonzo]

So why do the 2010 R1's have six pots on the front?

Later......

that's a damn good question....  

here is an interesting article i found on brake calipers....

http://www.superstreetbike.com/howtos/0906_sbkp_brake_calipers_explained/index.html

so to me it looks like if you want a smaller rotor (310mm on the 6 piston models = less rotational force/less unsprung weight) you would need 6 pistons working on it to achieve the same braking force as a larger rotor (previous version 320mm) would have using 4 piston calipers

so it looks like they switched to 6 piston calipers in order to have smaller diameter rotors which will improve transitional handling by decreasing unsprung weight.

howzat?

KOokaloo!

Very nice.  Unsprung weight vs. sprung weight....

Later...

[racerman_27410]

howzat?

Very nice.  Unsprung weight vs. sprung weight....

Later...

well i dont know for sure... i'm just trying to figure it..... out loud.   

maybe six smaller pistons dissipate heat better to resist fade....six pistons would definitely have a much larger surface area to carry the heat away from the pads....... with "longer" pads to more evenly spread the heat generated during braking.......and the increase in the amount of brake fluid to disperse the heat even more............ with it only being a side bonus of being able to use a 310mm rotor diameter to get the job done?



KOokaloo!

[fj1289]

so it looks like they switched to 6 piston calipers in order to have smaller diameter rotors which will improve transitional handling by decreasing unsprung weight.

howzat?

KOokaloo!

Frank,

I think you hit it on the head with this one.  The moment of inertia of the smaller diameter rotors would resist direction changes less.  I doubt I could feel the difference, but for the top level racers flinging these things from one side to the other probably could (as well as less fatigue for the fly-weight jockeys too).