Crosslink disk adapters, by OP. Pictures are at the bottom of the
(Remember, all modifications to your bike are
at your own risk here - if you screw up, don't be trying to sue myself, or
This will be the only time I post this so
get your copy and paste buttons ready 'cause once it's gone, it's gone.
Due to my time constraints and quite a few of you guys emailing me on info
- I'm posting this so you guys can have a copy of some basic info on how
this can be done. Keep in mind that this is the 'garage mechanics' version
of how to do this, people with a machine shop will have a much easier time
of things. We've used this technique and others for the aluminum leg
models and there are quite a variety of mounting techniques, adapters,
etc. For the aluminums but this is for the design I've made for the carbon
leg. You'll find from the design that there is very little torque on the
leg and leg mount. Most of the braking pressure is applied 'into' the leg
and very little pressure is place on the epoxy holding the mount in place.
the large half round plate was just a size that I picked that looked to be
sufficient to distribute stress - believe me, the first time down a steep
long hill when I really needed that front brake was "VERY
EXCITING" not knowing if I was going to be made into a shish-kabob.
we have never had any failures of any kind on this design. I only
undertook this adventure after consulting with the guys in the k2 tech
department, getting numerous ideas from others and a desire to push the
envelope a bit.
In all things like this, measure twice, cut
channel aluminum, 1 inch, 1/2 inch high,
3/4 inch internal channel, 6063 aluminum if possible
6061 T6 - 1 3/8 inner diameter aluminum
3/4 inch aluminum bar
drill and tap
marzocchi qr-20 disc mount fd51023-00
(from marzocchi - they buy them from a supplier)
a high quality multipurpose epoxy for
plastic and aluminum
Cut off a +/- 4 1/4 inch piece of the
tubing and then again along the length of the cut tube, an arc
approximating the bend of the leg. The idea is to set the edge of the
metal to the side of the leg, transferring the stresses of braking over a
wide area and to the sides of the leg as possible to prevent any buckling.
With a vise and or hammer and or whatever, increase the bend of the metal
slightly to accomodate the sharper bend of the leg on the inside where it
meets the flat internal side. Match the plate to the bend of the leg as
close as possible but leave room for error and it is best to 'over bend' a
bit to allow room for the mounting epoxy which will go underneath - too
close a match will press out all the epoxy later and weaken the bond.
Cut a +/- 2 1/2 inch piece of the channel
aluminum and bevel at a 45 degree angle, the inside lip of one side of the
channel. This will allow that side to sit lower than the uncut side when
put on the cut tubing. After the bevel, you can use a file or a dremel
tool, place the beveled side down upon the 'overbent' section of the cut
tubing. Put the whole thing on your leg and make sure you can
achieve a 90 degree face, perpendicular to the plane of the rotor. mount
your wheel and see if you're close - minor adjustments can be made when
epoxying and or shimming. the two pieces are now ready for welding -
make sure you have what would appear to be adequate space between the two
pieces of metal for some kind of internal fastening device, nuts
C-clamp the two pieces together to hold in
place making pencil marks as necessary in the event of minor movement and
weld. In the picture I supplied - the channel piece is backwards,
sorry - and that extra mount in my hand is just something I was playing
with from an "L" shaped piece of aluminum in the event i could
not get any more of the qr-20 mounts. They were out of stock for quite a
while. Put the unit on the leg and recheck for a 90 degree angle to
the rotor. minor filing, polishing etc. to the weld, edges etc for
aesthetics can be done at this time.
Mount the wheel with rotor, caliper to the
rotor and hold it in place by rigging up the levers to a bar and holding
the lever tight with a big rubber band.
Adjust the caliper on the rotor so it sits
Mount the reversed qr-20 with appropriate
bolts and spacers so that the qr-20 sits near the middle of the flat
mounting surface. The two surfaces should match up very closely if not
exactly. Readjust the caliper slightly if need be. you are now ready
to mark, drill and mount the qr-20 to the unit then epoxy the unit to the
leg or you can epoxy the unit to the leg at this time then mark, drill and
mount the qr-20 holes after it is installed.
Rough up the bonding surfaces, mix epoxy,
we use a 5-7 minute bonding type with a 2500-3000 rating for plastics and
aluminum. For the inside mounting device in the cavity of the unit,
you can use nuts to hold down the bolts or what we do is cut a piece of
3/4" wide aluminum bar, drill and tap to match the holes of the qr-20
and the corresponding holes in the flat surface of the channel aluminum. Y
You may want to experiment with a few
things to see what works best for you - I prefer to make my own plate as
dealing with nuts inside that little space is a pain in the butt and a
single piece of metal that slides in and out is much easier to work with.
you probably will have to carve off some of the metal with a half round
file to accommodate the internal bend in the tubing part of the main
Bond the unit to the leg using wheel
pressure from the mounted caliper to hold it in place - use clamps as
necessary on the ends. This means mounting the unit to the leg with all
parts assembled, in line and tightened down as you will be using them.
don't mount the thing if all angles are not perfect - work out the bugs
before you do.
Let the unit sit overnight to cure and you
should be ready to ride the next day. After mounting, any minor fudging
here and there can be made with spacers and minor homemade shims. I've
never had to do any additional shimming. From there, you can paint,
stripe, make some end caps to keep dirt out etc.
Since you may only get one shot at this, and if I could offer up a bit of
advice - "don't screw up"