Rotor truing (almost every ride)

I am running a pair of MX4 mechanical disk brakes (160mm). I have
noticed that I have to true my rotors after almost every ride.
My rides generally consist of 15-30km of rough, all mountain style
terrain (mud, rocks, clay, logs, grass, water).

What is the likelihood that my warping rotors is due to heat/cooling
(downhill braking, to puddle water)?
I have been keeping a close eye on the rotors, and am pretty sure I
have not hit them on anything the last few rides.

Any comments or recommendations would be great.

Mike
mlawrenc(at)gmail.com

Per mike:
What is the likelihood that my warping rotors is due to heat/cooling
(downhill braking, to puddle water)?

I warped the front rotors on my truck twice by dutifully hosing
off the undercarriage after trips on the beach.

Took me awhile to catch on.... but I finally got the point and
now I give things time to cool off before hosing.
--
PeteCresswell

On Sep 10, 8:40 am, "(PeteCresswell)" wrote:

I warped the front rotors on my truck twice by dutifully hosing
off the undercarriage after trips on the beach.

Took me awhile to catch on.... but I finally got the point and
now I give things time to cool off before hosing.
--
PeteCresswell

I highly doubt that washing your truck after a trip to the beach would
cause this. Automotive brake systems have a much better heat transfer
system then my single ply mechanical disk brakes.
First off, my stock brakes on my wife's car (using this as an example
because it was not a performance vehicle) consist of rotors that
contain cooling fins in the center of the rotor.
Second, the calipers are and brake fluid are also used for heat
transfer.
Her brakes did get some heat warp when she started commuting to work.
This was caused from hard frequent braking at high speeds during cold
weather. The rotors would go from an air temp of say -5'C at 120kmph
to full stop.

Now, as for my bike brakes;
We are talking single ply (3mm thick?) and 160mm in diameter. Little
to no heat absorption from braking system (mechanical brakes).
These rotors do get very hot easily. It is not uncommon to do hard
braking before entering into water or mud. As with my wife's commuting
example, the rotors are going from cool, to hot, to cool again in a
very short amount of time.

Mike

"mike" wrote in message
...
: On Sep 10, 8:40 am, "(PeteCresswell)" wrote:
:

(Snipped)

: Now, as for my bike brakes;
: We are talking single ply (3mm thick?) and 160mm in diameter. Little
: to no heat absorption from braking system (mechanical brakes).
: These rotors do get very hot easily. It is not uncommon to do hard
: braking before entering into water or mud. As with my wife's commuting
: example, the rotors are going from cool, to hot, to cool again in a
: very short amount of time.
:
: Mike

This may be a dumb question but are the rotors being installed the correct way around?

Most Rotors are directional for strength so should you use them back to front they may prematurely
fail. Also the additional stress would easily warp a rotor with hard braking.

Just a thought.

Now, as for my bike brakes;
We are talking single ply (3mm thick?) and 160mm in diameter. Little
to no heat absorption from braking system (mechanical brakes).
These rotors do get very hot easily. It is not uncommon to do hard
braking before entering into water or mud. As with my wife's commuting
example, the rotors are going from cool, to hot, to cool again in a
very short amount of time.

Mike

Hi Mike
The starting thickness of the MTB disks is 2mm or 1,8 on the Hope Mono
mini Pro.
Generally on the mechanical brakes at the caliper level you can see
that only the external pad moves in, the internal pad is hand
adjustable. So, when the pads wear out, if you don't adjust the
internal pad to be very near the disk, when you act the brake lever
you will see that the disk will be pushed inward from the external pad
to be able to touch also the internal pad.
This can warp the disk on mechanical disk brakes.
Try to see what happens to your disk when you act the brake lever (not
while cycling!).
Bye Maurizio