Roadster XL1200CX Swing Arm Build

[ironpac]

I started this thread in the main section but I figured I put it here in the sporty section where it belongs.

Last year, I decided I am bored with my "club style" Sportster and decided to challenge myself. This is a first of everything, fabrication, welding, painting, etc. and learned as I go.

You can check my progress video on Youtube, IronPAC NY https://www.youtube.com/watch?v=Oz5P...EW05Fa3MUVXdrO

What the bike looked a year ago.


Took off the fairing, tank, seat, Ohlins, and other parts. Sold it to fund this build.


My plan was to build a Japanese style swing arm chop. The recipe for a correct stance is a small cool tank, and right length of swing the arm.

Mock up shots, decided I like the look of a Frisco Tank (EFI)

[ironpac]

I started with the swing arm. Extending it 6" over stock. Bought 2 swing arms from ebay which cost about $35 each, great deal. One will be the pivot and the other will be the extension. Using OEM swing arms allows me reuse the stock rear brake.

Bought two 2-feet of steel bar, cut it in 4. I machined them to size using flap disk can belt sander. Slug them in between the swing arm tubes.



Since it is going to be 6" over, the shock mounts will be further which I don't like. I fabricated mounting tabs for to weld it on closer to stock.

[ironpac]

Instead of making a jig, I used the bike as the jig. Installed the swing arm onto the bike, put on the wheels with the spacers. Used some swing arm struts to hold the mounting tabs in place.

It does not show in the pictures, but I did an extensive measurement with ruler and level. Making sure everything is aligned, symmetrical, and straight. My reference point was the bike frame.

After I convinced my self that everything was good, I welded all the parts in place.

Video is on my Youtube channel https://youtu.be/okUjsO-LT_M

[ironpac]

At that time, I was undecided with the rear fender, and my frisco tank was rusting so I went ahead and painted it.

I made a little spray booth in my garage using large garbage bags. Used Duplicolor spray cans for the primer, base, flames, and clear. Blue taped the flames, took me a few hours to freehand the hotrod flame patterns.

[ironpac]

For the rear fender, I combined two OEM fenders I have laying around so it covers the wheel all the way down to the swing arm. Makes it look complete. I cut two round 2" wide steel plate and used it as a brace/support on each side of the fender.



For the seat and fender mount




Welded it right on the stock frame.

[ironpac]

Bought a LePera seat from ebay but the rider seat does not work well with the bike geometry so I just stashed it, bought a cheap solo seat and used the passenger pillion.

Mock up shot. Big changed from what it looked from when I started the build. Once I got the fender squared, I painted it. Same method, used spray cans on the primer, base, and flames. But this time I bought a spray gun and used that to do apply a nice clear.

[ironpac]

To make it more exciting and challenging for me, I decided it has to be foot clutch and jockey shift. The first version I did was trash and gave me some problems so I simplified it.

Fabricated some steel and used brass bushings. Used a shifter peg as a foot rest when clutching.



The smaller pipe is where the clutch cable will loop and get crimped.

[ironpac]

For the electrical, I wanted a clean handlebar. Since this is a 2016 with CanBus protocol, it means you cannot just cut switch wires and solder it.

I bought a Namz CanBus controller, so all custom switches will go to this controller and it will communicate with the CanBus on the bike. It was a tedious process but an easy one. Just took my time and went slowly.





I located the turn signal, horn, hi/lo beam, kill switch, and starter all underneath the tank. Made switch boxes from plastic boxes

[ironpac]

I tried as much as I can to clean up the wiring on a modern Sportster. All wiring and connection plugs I wired towards the electric box under the seat. I purchased a small 12 Cell Lithium Battery and that gave me a lot of room for the CanBus Controller and wires.




Fabricated a headlight bracket that bolts on under the top tree. Cut two metal plates, bent, drilled, and welded them together.

[ironpac]

Finished sorting out the electrical over the weekend. Checked all the switches and they are all functioning.

Pulled her out of the garage, did the first start, cranked clean, she fired, she is alive!!! She stuttered a bit, died a couple times on idle but that is okay since she sat in the garage for a year. Just a few more things to do like chains, bleed brakes, loctite here and there, etc. and she will be road worthy!


Start video here https://youtu.be/_FL7cQmduV4

[CycleFreak]

Funky as shit. I love it.

[ironpac]

Funky as shit. I love it.

Appreciate that !

[Skjoll]

Damn dude, that looks really nice. It's stretched enough to lower the rear and give the bike a killer chop/drag stance.

[farmall]

That should ride much better than stock with the longer wheelbase and greater rear wheel travel.

I'd make sure the tire doesn't kiss the rear fender when the shocks bottom out. If in doubt ya can always remove the spring from one shock then use just that to lower the bike to see what hits first. S&W used to sell split bushings that clipped around their shock absorber shafts as bump stops to fine adjust where the stopping point would be. Your swingarm mod is similar to what dirt guys did to enduro and MX bikes for more travel in that era.

[ironpac]

Damn dude, that looks really nice. It's stretched enough to lower the rear and give the bike a killer chop/drag stance.

Thank you! Exactly what I was after, chop/drag stance.

That should ride much better than stock with the longer wheelbase and greater rear wheel travel.

I'd make sure the tire doesn't kiss the rear fender when the shocks bottom out. If in doubt ya can always remove the spring from one shock then use just that to lower the bike to see what hits first. S&W used to sell split bushings that clipped around their shock absorber shafts as bump stops to fine adjust where the stopping point would be. Your swingarm mod is similar to what dirt guys did to enduro and MX bikes for more travel in that era.

Thanks for the advice. That definitely helps.

[ironpac]

I was hoping to get this done this month but, some little accident and I ended up with 6-stitches on my hand and set me back on finishing the build.

During Holidays, I bought a used Nissin Front Brake Master Cylinder on ebay. Comes with a nice Rizoma remote reservoir. This should give the Harley a better braking and feel, hopefully haha.



Cleaned it, bored out to 1" using a step drill, and then painted it.



Since my set up is two lines from the master, I bought a new double banjo bolt 10mmx 1.0 (since this the Nissin was from a BMW). The gold Pazzio lever does not go well with the build so I replaced it with a black lever.

[ironpac]

If it's not too freezing in my garage this weekend, I want to finish up some things, like put some brake fluid, put the chains, locktite some bolts, etc. and hopefully get her on the road for the Spring.

[Skjoll]

Did you calculate the size of the master's piston you'll need in relation to the calipers you're using?

Vintage Brake, a company that specialized in race motorcycle brakes, used to have a great chart for determining piston size but Michael 'Mercury' Morse, the brains behind the operation, may either be out of business now or is no longer with us so his site that was up since the mid 90s appears to now be dead. I'll try to find his chart among the survivors of a hardware catastrophe I 'incurred' 15 years ago but less than 5% of the data in those drives was recovered and I'm not sure the chart was among that.


***Addendum (reason for editing)***

I found it, hope it's informative. Something to keep in mind, dual opposed piston calipers are different than the more common dual piston floating calipers which have the pistons on the same side and their MC piston sizes will differ because of that.

About Michael 'Mercury' Morse.

[ironpac]

Yes. There was a post about it being 11/16" for dual calipers. This one is 17mm bore.