How to Use the DT-5.2 Disc Brake Mount Facing Set

Aug 24, 2023

How to Use the DT-5.2 Disc Brake Mount Facing Set

More information on the DT-5.2: http://www.parktool.com/product/disc-…

This video will run through the process of setting up the DT-5.2 Disc Brake Mount Facing Set and using it to face disc brake mounts. The DT-5.2 can face Post Mount, IS Mount, and Flat Mount disc brake mounts.

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Content

0 -> Hi, I'm Max with Park Tool, and today we're going to be running through the instructions on

3.54 -> how to use a DT-5.2 Disc Brake Mount Facing Set.

8.46 -> The DT-5.2 works on IS mounts, Post Mounts, and Flat Mounts

12.6 -> It works in frames with widths from 135 to over 200 millimeters

17.5 -> and in forks with widths from 100 to over 150 millimeters

21.2 -> and it also works on axle sizes from 12 millimeters to 20 millimeters.

26.6 -> In this video, we're going to set up and face a Post Mount system.

30.36 -> We'll also show the setup procedure for an IS Mount system,

33.48 -> a rear flat mount system, and a front flat mount system.

37.18 -> And before we begin, remember to always wear safety glasses and always use cutting fluid.

44.34 -> Let's get started. In our first example, we'll be facing a post mount adapter on a 12mm thru axle rear end.

51.6 -> For this, we will need our post mount cutter

54.76 -> and our adapter to adapt the axle as well as the 12mm thru axle adapter.

61.34 -> When you assemble these parts together, it is very important

64.48 -> to note the orientation of the slider and the arm:

68.76 -> the slider needs to be above the arm with the sliding going down.

79.46 -> So, bring these together -

84.32 -> and now we can mount it onto the frame.

88.4 -> First step in putting it on the frame is to remove the thru axle

93.42 -> and then insert the thru axle and body together into the frame.

103.22 -> Just get this thru axle engaged so that everything hangs.

106.08 -> Set the width by sliding out the telescoping inner piece and then set that with using this 5mm bolt.

118.1 -> Then tighten the axle into the frame and put pressure onto the entire assembly to keep it snug.

130.8 -> Now that we've got the axle in the frame, we can set the parallelism.

134.14 -> In order to do that, simply bring these wings into contact with the post mounts.

141.16 -> First, tighten the bolt between the cutting arm and the slider

145.06 -> and then tighten the bolt on the body between the body and the axle.

151.58 -> Now you have established your parallelism and you're ready to make your first cut.

157.98 -> Transition to one of the mounts again

162.02 -> Again, tighten the slider bolt in place, install the knob

167.58 -> Always important to use cutting fluid whenever you're cutting - helps keep the tool life longer

175.42 -> and with light hand pressure you can make your cut

182.7 -> and you will turn until you see a consistent ring all the way around - we're not quite there yet.

197.2 -> Getting close, but not quite.

198.88 -> Onto that consistent range of silver all around that mount, so we'll cut just a little bit further.

209.24 -> Always important to keep adding cutting fluid

215.9 -> So at this point we've cut quite a bit of surface off.

218.28 -> We've got a small low spot here, but it's not going to impact our mounting surface

222.96 -> So we're going to move on to setting our stop collar height that establishes our baseline level for the cut

228.83 -> so we bring this caller up and tighten it into place and that needs to be in contact with the slider

235.56 -> so the slider body will be in contact with this when this cutter is in this hole.

240.66 -> Now we have a baseline, we can transition to the other stop.

245.24 -> So we bring that over here, tighten this bolt again,

248.46 -> we can see that we now have a small gap between our slider and our stop collar

252.68 -> which means we've got room to cut on this post

255.6 -> so add a little bit more cutting fluid and start to cut.

266.07 -> Now we're going to continue cutting until we see this gap go away - we've got a ways to go

273.74 -> but we're getting there.

276.5 -> so now we have bottomed out our slider on this stop collar.

279.74 -> We are in a position where one of two things could be possible:

282.98 -> either we are done facing and we have a complete ring,

286.04 -> or we need to continue facing and then come back and reface the upper post

291.8 -> So in this case we still have black here, so that means we need to continue facing.

297.6 -> If this were silver all the way around, we would be done at this point

300.54 -> but since it is not, we will continue facing.

304.14 -> We will drop our stop collar and continue to face until we have that clean silver ring all the way around.

313.22 -> Check this surface - it looks like we have a nice clean surface now so we'll set this cutter back down

318.28 -> make sure it's clean, set this cutter back down and re-establish our baseline height.

326.68 -> Now we can transition back to the top post

332 -> We can see we have a small gap again as expected

338.66 -> and we will continue to face this until that gap goes away.

346.04 -> We can see that our gap is now gone. We've stopped cutting and our facing is complete.

355.64 -> In this case, we have open dropouts coupled with an IS Mount

360.86 -> so we will need our IS arm, as well as the slider and stop that we used previously,

370.06 -> and for the open dropouts we need our open dropout axle.

377.91 -> In assembling these parts, it's important to know that the slider is oriented to the cutter like so.

389.66 -> The stop collar goes underneath the slider, slide everything over this axle, and you're ready to install it into the frame.

400.18 -> The first step in installing it into the frame obviously is fitting it into the dropouts.

404.12 -> In this case you'll need to telescope the axle out, slide it into the dropouts,

410.78 -> snug both ends

416.88 -> and then tighten securely into the drop out before tightening this stop collar.

428.22 -> Now that everything is tight, your parallelism is automatically achieved because you are on the axle,

433.4 -> and all the steps for facing are the same as with the Post Mount from here on out

439.1 -> and you're ready to face.

446.12 -> In this case, we have a flat mount disc brake with a thru axle rear end.

452.02 -> The DT-5.2 comes with some additional parts to allow you to face Flat Mounts.

458.04 -> It comes with a set of standoffs for the rear

464.84 -> as well as a set of standoffs for the front and a replacement bolt for the front - we'll get to those later.

469.92 -> In the rear, you use two standoffs - they go into the frame, one in each slot.

477.3 -> They have an O-ring that allows them to keep their place once inserted.

482.64 -> The setup for a Flat Mount uses the same parts as a post mount, but oriented slightly differently.

488.02 -> Use the post mount cutter as well as the post mount body,

492.26 -> but for the slider, instead of having the slider like so, you flip the slider like so.

505.74 -> Slide it all together

507.86 -> Select our thru axle rear axle and we are ready to insert it into the frame.

516.26 -> Again, you slide the thru axle adapter in, put it into the frame, slide your thru axle through the entire part

527.44 -> lightly start it, then set your spacing.

537.94 -> Tighten the clamp here and then snug your axle.

543.96 -> Now you're ready to establish parallelism - bring the cutter body and set it onto the studs

551.5 -> then you tighten the bolt between the cutter arm and the slider

556.36 -> and then finally you tighten the body onto the axle.

562.12 -> Now the last step: pull these studs out to reveal the mounting surfaces themselves

570.48 -> and you're ready to face.

572.34 -> The procedure for facing is the same as demonstrated earlier on the Post Mount system.

578.68 -> In this case we have a flat mount front on a 12mm thru axle fork

584.56 -> so we need some unique parts we haven't seen before:

586.84 -> we've got these additional parts that adapt the Flat Mount to the Post Mount.

593.86 -> The parts you'll need from this kit are your Post Mount adapter,

598 -> your 12mm thru axle front, which is this sleeve in addition to the 15mm, and the body there

608.06 -> so just like with the other flat mount, you need to make sure that your slider goes on like this

617.26 -> so we'll get that set up

620.92 -> and additionally, you'll need to change out this silver bolt in place of this black bolt.

630.88 -> To do that, simply take your knob, set it on there, hold the knob firm, insert a 4mm,

645.32 -> The bolt will back out, insert your new bolt

654.06 -> and you've converted now to be able to face the front of a Flat Mount.

659.92 -> Take these two standoffs, install them into your fork

664.8 -> these standoffs are threaded, so they thread into the holes on a Flat Mount fork - get them nice and snug.

673.46 -> Bring over the rest of your parts, again install the adapter into the body, pull your axle out

684.54 -> install into the frame

688.86 -> start the axle

692.8 -> snug that width

698.6 -> and then tighten the axle

702.56 -> now we proceed with parallelism - exactly similar to the rear Flat Mount where you locate on the studs and tighten the slider

714.62 -> and tighten the slider and then finally tighten the body

722.5 -> and now remove the studs and you're ready to face.

727.78 -> the procedure for facing is the same as demonstrated earlier on the Post Mount system.

734.26 -> That was the basic procedure on how to use the DT-5.2. Thanks for watching.

Source: https://www.youtube.com/watch?v=zBsqYnYj_sE