Hi, I'm Max with Park Tool, and today we're going to be running through the instructions on
how to use a DT-5.2 Disc Brake Mount Facing Set.
The DT-5.2 works on IS mounts, Post Mounts, and Flat Mounts
It works in frames with widths from 135 to over 200 millimeters
and in forks with widths from 100 to over 150 millimeters
and it also works on axle sizes from 12 millimeters to 20 millimeters.
In this video, we're going to set up and face a Post Mount system.
We'll also show the setup procedure for an IS Mount system,
a rear flat mount system, and a front flat mount system.
And before we begin, remember to always wear safety glasses and always use cutting fluid.
Let's get started. In our first example, we'll be facing a post mount adapter on a 12mm thru axle rear end.
For this, we will need our post mount cutter
and our adapter to adapt the axle as well as the 12mm thru axle adapter.
When you assemble these parts together, it is very important
to note the orientation of the slider and the arm:
the slider needs to be above the arm with the sliding going down.
So, bring these together -
and now we can mount it onto the frame.
First step in putting it on the frame is to remove the thru axle
and then insert the thru axle and body together into the frame.
Just get this thru axle engaged so that everything hangs.
Set the width by sliding out the telescoping inner piece and then set that with using this 5mm bolt.
Then tighten the axle into the frame and put pressure onto the entire assembly to keep it snug.
Now that we've got the axle in the frame, we can set the parallelism.
In order to do that, simply bring these wings into contact with the post mounts.
First, tighten the bolt between the cutting arm and the slider
and then tighten the bolt on the body between the body and the axle.
Now you have established your parallelism and you're ready to make your first cut.
Transition to one of the mounts again
Again, tighten the slider bolt in place, install the knob
Always important to use cutting fluid whenever you're cutting - helps keep the tool life longer
and with light hand pressure you can make your cut
and you will turn until you see a consistent ring all the way around - we're not quite there yet.
Getting close, but not quite.
Onto that consistent range of silver all around that mount, so we'll cut just a little bit further.
Always important to keep adding cutting fluid
So at this point we've cut quite a bit of surface off.
We've got a small low spot here, but it's not going to impact our mounting surface
So we're going to move on to setting our stop collar height that establishes our baseline level for the cut
so we bring this caller up and tighten it into place and that needs to be in contact with the slider
so the slider body will be in contact with this when this cutter is in this hole.
Now we have a baseline, we can transition to the other stop.
So we bring that over here, tighten this bolt again,
we can see that we now have a small gap between our slider and our stop collar
which means we've got room to cut on this post
so add a little bit more cutting fluid and start to cut.
Now we're going to continue cutting until we see this gap go away - we've got a ways to go
but we're getting there.
so now we have bottomed out our slider on this stop collar.
We are in a position where one of two things could be possible:
either we are done facing and we have a complete ring,
or we need to continue facing and then come back and reface the upper post
So in this case we still have black here, so that means we need to continue facing.
If this were silver all the way around, we would be done at this point
but since it is not, we will continue facing.
We will drop our stop collar and continue to face until we have that clean silver ring all the way around.
Check this surface - it looks like we have a nice clean surface now so we'll set this cutter back down
make sure it's clean, set this cutter back down and re-establish our baseline height.
Now we can transition back to the top post
We can see we have a small gap again as expected
and we will continue to face this until that gap goes away.
We can see that our gap is now gone. We've stopped cutting and our facing is complete.
In this case, we have open dropouts coupled with an IS Mount
so we will need our IS arm, as well as the slider and stop that we used previously,
and for the open dropouts we need our open dropout axle.
In assembling these parts, it's important to know that the slider is oriented to the cutter like so.
The stop collar goes underneath the slider, slide everything over this axle, and you're ready to install it into the frame.
The first step in installing it into the frame obviously is fitting it into the dropouts.
In this case you'll need to telescope the axle out, slide it into the dropouts,
snug both ends
and then tighten securely into the drop out before tightening this stop collar.
Now that everything is tight, your parallelism is automatically achieved because you are on the axle,
and all the steps for facing are the same as with the Post Mount from here on out
and you're ready to face.
In this case, we have a flat mount disc brake with a thru axle rear end.
The DT-5.2 comes with some additional parts to allow you to face Flat Mounts.
It comes with a set of standoffs for the rear
as well as a set of standoffs for the front and a replacement bolt for the front - we'll get to those later.
In the rear, you use two standoffs - they go into the frame, one in each slot.
They have an O-ring that allows them to keep their place once inserted.
The setup for a Flat Mount uses the same parts as a post mount, but oriented slightly differently.
Use the post mount cutter as well as the post mount body,
but for the slider, instead of having the slider like so, you flip the slider like so.
Slide it all together
Select our thru axle rear axle and we are ready to insert it into the frame.
Again, you slide the thru axle adapter in, put it into the frame, slide your thru axle through the entire part
lightly start it, then set your spacing.
Tighten the clamp here and then snug your axle.
Now you're ready to establish parallelism - bring the cutter body and set it onto the studs
then you tighten the bolt between the cutter arm and the slider
and then finally you tighten the body onto the axle.
Now the last step: pull these studs out to reveal the mounting surfaces themselves
and you're ready to face.
The procedure for facing is the same as demonstrated earlier on the Post Mount system.
In this case we have a flat mount front on a 12mm thru axle fork
so we need some unique parts we haven't seen before:
we've got these additional parts that adapt the Flat Mount to the Post Mount.
The parts you'll need from this kit are your Post Mount adapter,
your 12mm thru axle front, which is this sleeve in addition to the 15mm, and the body there
so just like with the other flat mount, you need to make sure that your slider goes on like this
so we'll get that set up
and additionally, you'll need to change out this silver bolt in place of this black bolt.
To do that, simply take your knob, set it on there, hold the knob firm, insert a 4mm,
The bolt will back out, insert your new bolt
and you've converted now to be able to face the front of a Flat Mount.
Take these two standoffs, install them into your fork
these standoffs are threaded, so they thread into the holes on a Flat Mount fork - get them nice and snug.
Bring over the rest of your parts, again install the adapter into the body, pull your axle out
install into the frame
start the axle
snug that width
and then tighten the axle
now we proceed with parallelism - exactly similar to the rear Flat Mount where you locate on the studs and tighten the slider
and tighten the slider and then finally tighten the body
and now remove the studs and you're ready to face.
the procedure for facing is the same as demonstrated earlier on the Post Mount system.
That was the basic procedure on how to use the DT-5.2. Thanks for watching.