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Discussion Starter #1
I finally got my swingarm on my 87 FXRC dismounted. I decided it was high time I reinstalled my belt drive. But then I decided I should upgrade the swingarm since H-D hadn't done the best job in designing it in the first place. The rectangular tubing isn't such a good idea and it tends to get crushed inward especially if the rider overtorques his axle nut. Also I acquired an H-D Airstrike rear wheel with the 1" rear bearings so I'm going to have fabricate a new axle for this project. One problem I've already encountered was that my new wheel had a completely different width then my old 9 spoke AMF wheel so I've got to come up with new wheel spacers to get my rear pulley properly centered. This is the first time I've put my efforts into a rear suspension upgrade. Most of my previous efforts have been toward designing and building 49mm front ends for Sportster, Dynas and also this FXR.
265531
 

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Discussion Starter #2 (Edited)
I have an FLT [I think that's what it was off of] rear axle and it mikes out .994" or .995" not 1.000" which it was supposed to be. I haven't put my telescoping gages on the Airstrike wheel yet. Here's a pic of the Airstrike rear wheel with 1.000" bearings.
265532
 

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Discussion Starter #3
Since I've got to make a one off rear axle I purchased these 1-14 UNF stainless nuts from McMaster-Carr. I'll chase threads on both ends and then weld one on to make a head. I haven't decided whether to buy 1" 304 stainless tubing with a .1875" wall or a .250" wall. I think the .1875 wall will be strong enough.
265533
 

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Discussion Starter #4
Here's my 1" bar stock I got from Modern Welding here in E'town today. They had to cut it out of a 1" plate because they didn't have any bar stock that sized. I was surprised how neatly the plasma cutter made the sides. I'm used to oxy-acetylene torch work which isn't nearly that neat! I'm going to fab my new swingarm fork ends out of this stock. As of now I plan to make all the dimensions on the upgrade the same as stock except for the 1" axle relief holes.
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That's some heavy stuff. Not sure what you got going on here but you seem to have a plan. I'm also a welder fabricator in NY. Interested to see what you have going on here.
 

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Discussion Starter #6
All will be explained! Here I'm just doing doing a full scale mockup with my wheel and the rear pulley. This pulley has H-D #40225-86A cast on it and apparently came stock on a 2000 Road King. Anyway it has 70 teeth just like my FXR manual calls for and is the correct with. The pulley clears the 130-16 American Elite tire by about .125" which is good enough! Now I have to figure out what sized spacers to use to get the belt to run true. There was a significant difference in the widths of the Airstrike and the AMF 9 spoke wheel.
265535
 

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Discussion Starter #7
Here's a shot of my spare FXR swingarm. I'll probably use my original for the project and keep this one just in case I mess up my project swingarm. When I disassembled the swingarm from the bike the original cleveblocs in it self destructed. The ones in this spare look to be in pretty good shape. With this spare I'll be able to restore the bike to original if I need to.
265536
 

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Discussion Starter #8
Here's my Colony belt or chain adjusting screws. They're stock on old H-D hardtails and modern softtails. They have a 7/16-20UNF thread on them you use them to push the rear axle rearward until your chain or belt has the proper tension and then you use another wrench to tighten the locknut. Crude but effective! I have to fabricate some brackets which will be welded onto the swingarm sides for these screws.
265537
 

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Discussion Starter #9 (Edited)
Here's a pic of a chromed V-Twin aftermarket H-D softtail swingarm. It's actually upside down. It shows you the type of axle mounts I plan to fab for my project. The softtail swingarm is stronger then an FXR or FLT swingarm because of it's triangular construction. However I'm not going to replicate a softail swingarm for my upgrade project. I'm just going to use the softtail axle mounts as a model for my upgrade.
265538
I measured the thickness of one of the axle mounts on a stock H-D softtail swingarm at Junction City Cycles yesterday and they were only .375" wide. The adjuster screw brackets were .9375" long. I'll make my new axle mounts .750" wide which is twice the stock size.
 

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Discussion Starter #10 (Edited)
Here I've mocked up an H-D Sunstar front 292 mm rotor [H-D #41822-10] which is stock on the XR1200 front end. The only problem I see so far is that the counterbored holes are clearanced for a 5/16" [.3125"] hole. The rear bolt hole pattern is exactly the same as on the front wheels but uses 3/8" rotor bolts.
265585
This rotor won't take the standard button head 3/8" torx screws H-D uses on their rear rotors so I'll have to open up the holes to 3/8", no big deal. The counterbores will clear a 3/8" socket head cap screw with no problem. But I may have to relieve my brake bracket slightly to clear the heads. They're taller then the ones on a torx buttonhead screw. My original FXR rear rotor had a lot of use and while it was still in spec I didn't try to salvage it because the 87 FXR rear rotor was fastened on with counter sunk flat head screws which can be a bitch to remove especially if your bike has been out in the rain [they have a real small socket]. On an older bike if you try to remove the screws you'll usually end up stripping out the sockets and then have to drill out the heads to get the rotor off.
 

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I get it, if you feel the need to run that late model bagger wheel on it, but past that all the FXR swingarm are needs is a set of block style adjusters. To increase the area clamped against.

pretty inexpensive to just buy em. Bout $25



What ever you do, try not to add weight to the wheel/swing arm. Adding a pound of unsprung weight is like adding 10 pounds of rider.
 

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Discussion Starter #12
I got my 1.000" 304 stainless tubing from Online Metals today. Looks like it'll do the job. I have a used '05 FLT axle and it mikes out to be .998" in diameter. I miked my Airstrike wheel bearings with my telescoping gauges and they're miking out .999" ID. So it looks like I'll have to clamp my axle stock up in my lathe and very carefully sand it down to .998".
 

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Discussion Starter #13 (Edited)
I took my swingarm fork to Wilson's Cycle here in E'town for them to press out the remains of my cleveblocks. I've got a 20 ton hydraulic press but I don't have the necessary hardware to get the old cleveblocks out. Then I started working on my axle. I rough cut it to length [actually slightly longer] and now I'm sanding the OD down so it'll go in the wheel. This was a tougher job then I thought it would be. I've got it about half way finished. Here's a pic of my new rear rotor. It's actually an H-D XR1200 front 292mm free floating rotor. I opened up the 5/16" bolt holes to 3/8" [.375"] and mounted the rotor with 3/8-16x1" socket head cap screws I bought a Lowes. I don't like the button head cap torx cap screws which Harley uses on their rotors. However I may have to relieve my rear brake bracket for the socket head screw because they're taller then the button head screws. The orginal FXR rear rotor screws were a flat head socket head screws which were notorious for stripping out after a few years especially if your bike had been out in the rain.
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Discussion Starter #14
I installed my rear pulley on my new wheel with 7/16-14x1.75" stainless socket head cap screws
265612
I ordered from Bolt Depot. They're my go to guys when it comes stainless fasteners especially hard to get types like the screws and nuts with fine threads. The hardware stores and Lowes and Home Depot usually don't carry them.https://www.boltdepot.com/Default.aspx
 

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Discussion Starter #15
Success!
I finally got my axle to go thru my hub! It took me several hours of sanding down the OD of my 304 stainless axle on my Grizzly 16x40 Gunsmiths Lathe before I finally got it to go thru! I first used 180 grit sandpaper and then went to a coarser 120. But I finally got 'er done. Tomorrow I've got to chase 1"-14 threads on both ends and then weld a nut on one end.
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Discussion Starter #16 (Edited)
Threading Completed
Here I've finished chasing the threads on my axle and installed the 1-14 stainless nut. I still have to chamfer the shaft end and the nut for my weld bead groove. I didn't screw this up. Even though I'm a retired tool and diemaker with decades of experience I've still managed to screw up a few threads now and then. It's easy to do! I'll wait until after I've successfully welded on the nut before I try chasing the threads on the other end of my axle.
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Discussion Starter #17
In the first pic I've just chamfered my nut. In the second pic I've threaded the nut onto to the shaft. It was binding at first and the nut wouldn't thread on all the way so I had set up to cut threads again, pick up threads and then recut them just a little bit. This where it's easy to mess up and ruin your threading job! Now I've got to weld the nut and shaft together. I think I'll take it up to a local machine shop because although I'm set up for stick welding I do have a heliarc machine but I'm not very good at it.
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Discussion Starter #18
Here's my axle after they welded on my nut. I took it to Elizabethtown Machine and Tool but their heliarc welder was down so they sent me to Elizabethtown Manufacturing Services a few blocks away. They did a good job except I wished I'd have told him not to grind the bead down. A good weld bead looks cool!
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Discussion Starter #20
Here's Mad Max's swingarm fork. I got it back from my Indy motorcycle shop today because they'd had it for three days and hadn't got 'er done! I was very disappointed in them since I knew the job shouldn't take more then a half hour if you've got the tools and the know how. Now I've got to make up the tools to do the job myself something I wanted to avoid!
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