Promax mechanical disc brake pad replacement
Ron Hardin
so I set about figuring out how to replace them.
It's not like what you'd get from google.
The old worn pads will come out through the disc slot, but the new ones
(Koolmax) are far to fat to go in through the slot.
1. There's a end cover with a hole in it, that fits the allen wrench
that you loosen the cable with. Unscrew it.
2. Sneak pads in through that hole, taking some advantage of the tabs
going in first.
3. The pads are not the same thickness. There's one labelled "in"
that's thinner - that one goes in first. The thicker one "out" goes
in last.
4. Screw in the cover again, but reverse the cover. That leaves more
room for the thicker pad. Apparently that's a design option for this case.
Why the option, I have no idea. But the parts do fit.
The magnet falls out if you reverse the cover, and is now somewhere in
my front yard. It does not appear to be necessary.
Anyway I think it was the magnet. It was something.
--
rhha...@mindspring.com
On the internet, nobody knows you're a jerk.
Ron Hardin
> (Koolmax) are far to fat to go in through the slot.
Koolstop, I should have written.
Chalo
>
> > The old worn pads will come out through the disc slot, but the new ones
> > (Koolmax) are far to fat to go in through the slot.
>
> Koolstop, I should have written.
That seems like a good move. Promax mechanical discs are the weakest
and least effectual disc brakes I have ever seen. But I have only
seen them equipped with the stock pads. Kool Stop pads may not make
those brakes into strong performers, but they couldn't hurt.
Chalo
Ron Hardin
It has a noticeably smoother stop, no non-metal-on-metal feel.
I have the feeling the thickness difference is supposed to extend lifetime,
by letting you reverse the cover and use more of the thicker pad as it wears,
sort of a two-step adjustment via the offset cover. The other pad is
adjusted with the cable.
Why not use an actual adjustment, though?
You'd adjust to keep the gap centered in the slot. Otherwise it follows
the non-cable pad as it wears.
Chalo
>
> Chalo wrote:
> >
> > Ron Hardin wrote:
> > >
> > > Koolstop, I should have written.
> >
> > That seems like a good move. Promax mechanical discs are the weakest
> > and least effectual disc brakes I have ever seen. But I have only
> > seen them equipped with the stock pads. Kool Stop pads may not make
> > those brakes into strong performers, but they couldn't hurt.
>
It has been a few years since I messed with a Promax brake, but I
would not have described the stopping qualities as "metal on metal".
More like wood on plastic.
> I have the feeling the thickness difference is supposed to extend lifetime,
> by letting you reverse the cover and use more of the thicker pad as it wears,
> [...]
> Why not use an actual adjustment, though?
Nickels and dimes, probably.
> You'd adjust to keep the gap centered in the slot. Otherwise it follows
> the non-cable pad as it wears.
Bicycle disc brake rotors are designed to flex laterally as
necessary. It's a little hokey, but it seems to work. The main
penalty is increasing lever takeup as the fixed pad thins out.
One of my bikes has an ancient Mountain Cycle Pro-Stop disc brake with
a fully floating 9" rotor. That system eliminates rotor flex, but it
has offsetting drawbacks in the form of noise and lash.
Chalo