4-pot caliper mounted backwards

I've recently mounted a four piston bolthole compatable caliper
on my bike in place of the original two pot. Piston areas are
about the same. Braking is markedly improved, mostly I suspect
because of the larger pad area.

One oddity about this swap is that the 34/32mm caliper now mounts
with the larger piston driving the leading (rearmost) edge of the
brake pads. In its original application, the leading edge was driven
by the 32mm piston and the trailing edge by the 34mm.

edge of the pads. Not sure what effect it'd have on stopping power.
Seems as if it might actually improve stopping. Might be possible
to get around the wear problems by swapping pad positions
occasionally, though this seems like a PITA.

I'm interested in any thoughts on this setup and what I might
expect long term.

 

just a thought:
if the caliper was designed, originally, to be on the other side disk of the
same wheel,
this would give the same situation.
i take it you have a single disk on the wheel, tho.
in the final analysis, i wouldn't expect much difference in the wear
situation.
there's not any 'servo effect' like some drum brakes.
good luck, sammmmm

 

The caliper is a left side caliper intended to mount behind the
fork, now mounted on the right side in front of the fork.

I'm kind of mystified why a mfr would go to the trouble of using
two different piston sizes if it had no effect and served no useful
purpose. Not to say this kind of stuff doesn't happen occasionally
though.

 

I'd have thought it was "mainly cosmetic" to attempt to get even
pad wear; the difference in force between 32 and 34 mm pistons (if I've
understood your description properly) is 34^2/32^2 = (17/16)^2, or +13%.
However, I can't quickly come up with a reason why two equal-sized
pistons would create asymmetric wear, tho' it seems to be widely believed:
http://www.buybrakes.com/brembo/faq.html#q12
So you might find the leading edge wearing ~25% more than the trailing...


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That explains why my equal sized piston caliers wear the pads unevenly.
It isn't much mind you, just about 10%. I think the leading edge of the
pad wears faster but I could be wrong. My calipers are behind the fork.

pierce

 

Dr Ivan D. Reid wrote:

<<Snip>>

Leverage. Forces are trying to rotate the pad as it rubs on the disc.