Why are rear brake pads different from the front?

They have a different Kawasaki part number and some aftermarket manufacturers of pads specify some as "Rear" and some as "Front". They are identical in appearance and some manufacturers show their pad can be used for front or rear.

So is there ever a difference in material for front versus rear? And if it's important, why, and why do some manufacturers ignore the difference?

No I did not google it. Speculate as necessary.

I don't think I have ever seen a difference in friction material except for upgrades to heavy duty/high performance use.
Marketing?
Bean counters?
Some desk jockey F'in 'it up again?


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I would guess they may be different compounds.
The front would have to survive a higher heat level without fade. As well as requiring more braking power due to the weight transfer on dry pavement.
The rears would not be as aggressive due to potential rear wheel lockup and wouldn't need to be as fade resistant as the front.
Kawasaki was probably having issues with overly sensitive rear brakes...hence the different part number.
Instead of changing master cylinder piston sizes, they just change the brake pad compound.
Some aftermarket manufacturers probably have figured out a braking compound that's works well as a compromise, but Kawasaki could make an aggressive compound for the front and less aggressive for the rear. Giving you an overall better braking combination.
If you are feeling curious, you could always swap rear to front----front to rear.
Just a hunch though.

rear is 1.5mm thicker than the front

photo: ecat.ferodoracing.com/product-line/motor...nd-shoes/code/FDB299


Photo: www.omniaracing.net/en/brembo-front-brak...821983-p-169688.html

Ah, so it's the thickness. Huh. I never noticed. I'll have to see if I can find specs on thickness in the manual somewhere. I wonder if aftermarket universals are averaging the two or just going with the thinner spec, or even the thicker spec.

This post hasn’t been updated by the op but I could be a similar thing. OP is trying to replace front pads but claiming the pad thickness is to great and not allowing the caliper to go back on the bike. :whistle: :whistle: :whistle:

kzrider.com/forum/5-chassis/613542-brake...cement-kz750?start=0

Well thicker rears would make sense seeing as though most riders tend to over use the rear brake versus the front. In fact one of our benchmarks on the department I worked for was watching how many rear brakes were being replaced on a given bike versus the fronts. Before advent of linked brakes we used to tell officers they should be replacing two sets of front pads to one set of rears. Good catch.

Rick H.

Yeah it will be interesting to hear what that OP says was the problem.