Hey everyone!
In the world of brakes the Shimano FREEZA rotors are some of the best
because of their extra cooling capabilities.
It used to be that these were available in the XTR and Saint line,
RT99 is the name of this specific rotor,
but with the introduction of 12 speed,
Shimano trickled down that technology to the XT grupo.
So I have the RT-MT800 rotor over here,
Let's take a closer look and see how it is the same
or different from the good old RT99.
This is an aluminum piece that is sandwiched between two pieces of steel
and that's how all the Ice Technologies discs from Shimano are made.
What's special about these FREEZA rotors
is the extended cooling fin that provides even better cooling.
Aside from that, you get the logo here on the face of the disc,
the product number which is the RT-MT800 for the XT,
manufactured in Japan, just like the old ones.
Rotation of the disc which is clearly specified with an arrow
and finally the size of your disc and also
the minimum safe thickness of this disc.
It is specified as 1.5 mm.
Straight out of the box disc comes with 1.75 mm thickness.
The RT-MT900 which is the XTR version of this
is almost identical, with the cooling fin being painted black.
Not much to see on the back of the rotor
aside from the cutouts in the aluminum spider
most probably to save weight.
The old XTR or Saint had a different shape of that cooling fin.
Also, the spider design was different.
I got my discs OEM so no box,
but Shimano uses the same one as in the past
obviously with the correct product code.
Center lock is the same attachment as before
aluminum spider, again identical,
and these discs can be used with both resin and metallic pads.
These are the sizes available and obviously
this would be an XT disc, XTR or Saint was the good old RT99.
On the scale the 180 mm disc comes up to 133 grams.
The 160 mm disc comes up to 106 g.
In comparison, the 160 mm RT99 came to 109 g
so almost the same weight as the previous generation rotors.
To install the discs you're going to need
one of these lock rings up front, and one of these in the back.
So either 10 or 8 grams added to the weight of the disc.
Shimano used to ship their Center Lock discs with this type of lock ring
which is perfectly fine for a QR type of axle on your bike.
Also works fine for the rear axle, so 12 mm axle.
As you move on to a front axle which can be 15 or 20 mm
you can see why this lock ring cannot be used, it won't fit.
So for that, you have to use the bigger one of the two
and installation of the disc is trivial:
you just slide your disc onto the spline
and then tighten the lock ring to 40 Nm
using a 16 notch Shimano BB tool.
And to be more precise with the tightening torque
you can use a socket type of BB tool
I'm going to put links in the description for tools like this.
The same bigger lock ring can be used on the back
so 12 mm or QR, you can see the torque specified, 40 Nm,
and in order to do that
you're going to use a cassette tool.
Finally, remove that warning label
that tells you not to touch the disc during install.
And because I know you're going to touch it anyway,
use some Isopropyl alcohol and wipe the disc clean
And before you hit the trails
make sure you bed in the brakes!
In that process, some of the pad material
is deposited on the braking surface of the rotor
and that gives you maximum power and longevity
of your disc and pads.
And why am I showing you a rotor straightening tool?
Because in the 2 years of ownership of these discs
I never had to touch them, they've been nice and round
and provide a great performance on this bike.
And after using these for two years with resin pads
you can see I'm down to about 1.69 mm from about 1.75 mm.
I know you're going to ask me is there any downside to using these rotors?
The only downside that I can see
is that you need the Center Lock interface for attaching these to your hubs
so you would have to buy the wheelset that supports this type of rotors
Are you guys planning to use any of the Shimano FREEZA rotors?
Pretty excited that they exist in XT format right now
that brought the price down a little bit.
But if you have any questions let me know in the comments below.
As usual, don't forget to like, subscribe,
keep an eye on social media.
And until next time
hope to see you folks on the trails.
Cheers guys, cheers!