Author Topic: Bronze Swing Arm Bushings For C5?  (Read 25941 times)

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gashousegorilla

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Reply #75 on: July 13, 2010, 01:21:57 am
I think pilot weight has a lot to do with it.  I agree with r80rt, mine seems ok, but I do not exceed 65 to 70 either, prefer a 45 -50 mph back road to the highway. the Enfield handles those roads far better than the Road King.   I am 5"11 at 195 dressed in riding gear.

I have never been a high speed rider so I really would not be able to recognize the symptoms that gashousegorilla experienced. But I am glad he broke from the pack and sorted it out for the rest of us. That is how innovation works.

-Quinn

 Thanks for the kind words ggolden.
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gashousegorilla

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Reply #76 on: July 13, 2010, 03:30:53 am
I still don't understand it, my C5 handles very well. I think the size of the rider has something to do with it, I'm 5'5" and weigh 175lbs with short legs. I sit a bit farther forward than most folks and I'm not tall enough to catch a lot of wind, it's feels a bit light over 70 but I almost never run over 60-65mph, it's very stable on the twisty roads around here and a ton of fun to ride. Or is this just a goofy theory?
Not goofy at all. Don't let my user name fool you, I'm not a Gorilla in stature by any stretch. Like you, if I may, I would say I'm below average in size. 5'8 or 5'9, bout 175lbs. And I'll go a little further and say the C-5 handles exquisitely on the county roads. Now I'm 3-4 inches taller then you, and there is about a 10 mph difference in our bikes stability, if all things being the same. Before this swing arm mod, other then a pedestrian slicer, my bike is bone stock. Your bit light at 70 mph, Things start getting getting scary for me. See my point? It should not Be.
 Someone said earlier in this thread, it has to do with expectations. Excellent point.And I expect a bike with a very modest claim of a maximum speed of about 82 mph to be stable for the average rider at that speed. For me , I live in a suburban setting, closer to city's then the country. And from time to time I have to jump on an interstate to get to those country roads. I simply would like to have a stable enough bike to feel confident about cracking open the throttle and passing that double hitched tractor trailer.I think my expectations are pretty reasonable,no?
 I did not purchase this bike to go tear a!!ing around, I build Cafe racer's for that. I bought it because it is an awesomely cool old school bike, that I did not have to do a thing to,or so I thought .I have a day job. I spend most of my free time working on,or building bikes for other people,so you can get my frustration.I don't mean to whine, I'll get it figured out. sorry for the rant.

Thanks, Dan
« Last Edit: July 13, 2010, 03:41:30 pm by gashousegorilla »
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ajithk

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Reply #77 on: July 19, 2010, 03:47:36 pm
I am late to this discussion but i hope this link helps. The author discusses a few options to brace swing arms which look like useful alternatives to others who want to give this a shot.
http://victorylibrary.com/brit/chassis-2a.htm

That swing arm looks like a poor cousin of a torsion-beam axle and though i am no engineer, i am surprised (and not pleasantly either) to see such a design. As Chinoy said, there are motorcycles in India running what would to you folks be lawn-mower engines with better designed swing arms.

Dan sir, great work with the brace! I am sure a lot of people will follow your path. I would humbly suggest flat sheets on top and bottom to form a box shape to reduce the possible deflection further. You could cut a circular hole in the middle of these sheets to reduce weight while keeping the stiffness. The only fly in the ointment i see is if something attaches to the small blob(??) between the swing arm pivot and your brace.

I had one question. When the swing arm goes back on the engine, how would one ensure that the rear wheel is along the same vertical axis as the front wheel? I have seen C5s with rear wheels canted over to the left (as seen from the rear) when in motion.


SSR

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Reply #78 on: July 19, 2010, 04:09:04 pm
Going by the manual when putting the swing arm back in, its should be aligned with two ruler like metal strips bolted on the top and bottom shock absorber.

The reason you see the bad angle at the rear is mostly due to the chain adjuster splines not the same no on either side.


Ducati Scotty

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Reply #79 on: July 19, 2010, 05:07:54 pm
From that article:
"The pivot shaft needle bearing is one of those “looks like a good idea” that doesn’t work. The original bushing is generally either self-lubricating (“Oilite”) or has a gease fitting nipple, but has far higher load capacity than a needle, and doesn’t require a specific minimum surface hardness (or finish) to run on.
    There is also no gain to be had in any event - the swing-arm pivot does not rotate in the bearings but only oscillates a few degrees, so the difference in friction is too small to matter. "

Good to know.  Probably best to do what Gorilla did or similar or maybe more so by boxing it in as you mentioned and radiusing the rear to match the tire.  Whatever you choose, it seems the stocker is, um, shall we say 'lacking'.

Scott


gashousegorilla

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Reply #80 on: July 20, 2010, 01:52:16 am
I am late to this discussion but i hope this link helps. The author discusses a few options to brace swing arms which look like useful alternatives to others who want to give this a shot.
http://victorylibrary.com/brit/chassis-2a.htm

That swing arm looks like a poor cousin of a torsion-beam axle and though i am no engineer, i am surprised (and not pleasantly either) to see such a design. As Chinoy said, there are motorcycles in India running what would to you folks be lawn-mower engines with better designed swing arms.

Dan sir, great work with the brace! I am sure a lot of people will follow your path. I would humbly suggest flat sheets on top and bottom to form a box shape to reduce the possible deflection further. You could cut a circular hole in the middle of these sheets to reduce weight while keeping the stiffness. The only fly in the ointment i see is if something attaches to the small blob(??) between the swing arm pivot and your brace.

I had one question. When the swing arm goes back on the engine, how would one ensure that the rear wheel is along the same vertical axis as the front wheel? I have seen C5s with rear wheels canted over to the left (as seen from the rear) when in motion.
Thanks for the kind words and that very useful link ajithk. I wish I had it before I started this modification. But all the same I think I would have done the modification the same way. I agree that a boxed, arch shape design would be stiffer, using 16 ga steel or a solid 10ga steel arched plate welded in between the side tubes. But as stated earlier in the thread I believe in going a little conservatively the first time around.
 The arched shape designs would improve the stiffness by a factor of two, the simple 1" cross brace improves it by a factor of about 1.40. Point is this is an unknown modification at this point, or at least as far as I know. We don't know what if any impact it will have on the frame of the bike.Particularly the side gussets where the pivot bolt mounts the swing arm to the frame.
  The arched shape designs we see on other bike's are usually , but not always, supported in the center of the span by another frame member, like a stamped  steel post if you will.
  The blob as you so kindly put it ::), again was explained earlier in this thread. I don't see it as an issue unless you were to ride on mirrored roads ;). Again this being the first, and in absence of a Jig, it was a accurate way to adjust the dimension's of the swing arm for ease of installation of wheel, the ability to adjust the chain/wheel alignment, without too much stress on the wheel bearings. The 1" brace was welded in, sliced, adjusted, and welded back together with a 1/4" piece of flat stock.
 Or maybe you were reffering to my fat little friend? :D
 Thanks ,Dan.
« Last Edit: July 20, 2010, 01:56:35 am by gashousegorilla »
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gashousegorilla

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Reply #81 on: July 20, 2010, 02:26:27 am
Going by the manual when putting the swing arm back in, its should be aligned with two ruler like metal strips bolted on the top and bottom shock absorber.

The reason you see the bad angle at the rear is mostly due to the chain adjuster splines not the same no on either side.
Or you could just use the shock absorber. There is nothing to align really. The position of the swing arm in the frame is determined by pivot bolt mounting area's. I suspect it's stated that way in the manual because thats how they do it at the factory. It's cheaper to use a couple of pieces of drilled out flat stock, than to give the guy at his assembly station  a pair of pricey shocks. They can also sell the dealer this handy specialty tool. :D
In my work on the swing arm, really saw no need for it.
 I also forgot to mention earlier on in the thread, that the reason, at least in part, for your axle/ chain adjusters not being on the same notch, is because the swing arm side tubes are not perfectly symmetrical. Remember when I said that when you loosen the axle nut, the swing arm springs open? Well, with the stock swing arm having so much flex, when you tighten everything up, the side tubes do not pull in at the same rate. Leaving the rear wheel misaligned in the swing arm. It's really not an issue per say, as long as you have a slotted section in the swing arm, where the axle passes, to adjust for irregularity's. All bikes have them, for the most part. But with the week swing arm design on the C-5, you just have to use more of that slot to compensate. Another words, if your axle adjusters are not on the same notch, it's probably cool , as long as your alignment is OK.
 Dan.
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Ducati Scotty

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Reply #82 on: July 20, 2010, 04:55:15 am
Yup, align the wheel to the bike frame or the other wheel.  Little marks on the swingarm are always inaccurate.  I usually just lay a ruler or other straight edge along the rear sprocket, it should fall in line with the chain.  Unless the engine is really crooked in the frame it's certainly close enough and is really quick.

Gorilla, did you leave the rear of the swingarm open a little bigger than the width of the wheel?  How much?  Just thinking in advance.  I'll have to get this done since I don't weld.  I figured I'd put a bolt across the rear to hold it at a set width while the piece gets welded.  Keeps things in line.

Scott


gashousegorilla

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Reply #83 on: July 20, 2010, 06:36:40 am
Good idea Scott. Threaded rod, 4 nuts, 4 washers. Lock  everything in place. At the point where I sliced the 1" brace, in the center, it was about 1/8". What I did was to then wedge the sliced brace with a steel chisel,and then check for correct fitment on the    fully assembled rear axle/wheel , open up Slice to fit 1/4 inch stock, then weld it up. What the spread is at the rear where the axle slot is, I'll have to loosen up the axle nut and measure it for you, let me know when your ready. But to be honest Scott, I think doing the wedge technique is more accurate and more forgiving.And not that much more work. I would bet that there are variations from swing arm to swing arm. Remember, those two side tubes are over 18" and  what are the chances of getting perfectly straight sections from bike to bike? Especially after factory welding. Those side tubes are just butted against the pivot tube, at an angle and welded in place. I don't know how good their jigs are. so what worked for me, may not for you. What happens to the Brace, when you weld it, is that it shrinks over it's length from it turning from a solid to a liquid. difficult to predict. HOT LAVA!!! Be careful because the side tubes flare out from each other, so the axle slots are going to measure narrower at the front then at the rear. It is probably best just to fit it.
 Your welder should be able to do it, no prob. Just bring him the wheel assembly and show him how it goes together.
 Dan.
« Last Edit: July 20, 2010, 07:02:03 am by gashousegorilla »
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ajithk

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Reply #84 on: July 20, 2010, 01:13:01 pm
 The blob as you so kindly put it ::), again was explained earlier in this thread. I don't see it as an issue unless you were to ride on mirrored roads ;).
I did not mean the brace itself. Between the attach point of the brace on one of the arms of the swing arm, and the bar which also forms the pivot, there seems to be an attach point (The blob). I suspect the brake stabilizer rod attaches there?

   Or maybe you were reffering to my fat little friend? :D
 Thanks ,Dan.
;D hehehe


Ducati Scotty

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Reply #85 on: July 20, 2010, 01:52:23 pm
Dan, I suspect their jigs and final products all have a little play.  I was just wondering how much.  I have a friend of a friend who's a welder and a couple of frame shops in town, I'm sure someone can do it.

Also, yeah, just butted up and welded?  While it's in the welder's hands I'd have him put some gussets on the joints at the pivot tube.  Of course then I'd have to get the bushings out first....

Scott


gashousegorilla

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Reply #86 on: July 20, 2010, 04:29:25 pm
I did not mean the brace itself. Between the attach point of the brace on one of the arms of the swing arm, and the bar which also forms the pivot, there seems to be an attach point (The blob). I suspect the brake stabilizer rod attaches there?
 ;D hehehe
Oh,OK,sorry ::). on the right hand side of the swing arm ,near the junction of the side tube and pivot tube, is a welded in threaded  bung. This is an attachment point for the chain guard.
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gashousegorilla

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Reply #87 on: July 21, 2010, 01:06:45 am
Dan, I suspect their jigs and final products all have a little play.  I was just wondering how much.  I have a friend of a friend who's a welder and a couple of frame shops in town, I'm sure someone can do it.

Also, yeah, just butted up and welded?  While it's in the welder's hands I'd have him put some gussets on the joints at the pivot tube.  Of course then I'd have to get the bushings out first....

Scott
Yup, Butted up. They were probably fish mouthed though.Welds did not look bad, I don't think I would worry about them breaking. Bushings are easy, to remove without destroying, with a LITTLE heat and a wooden dowel, just carefully tap around the inside edges. If you install gusset's , just be sure to leave clearance for the chain guard mount on the right side.Have him grind everything nice, get a can of self etching primer, a can of color, sand paper and good to go. I used chip resistant Duplicolor caliper paint. My bike is black, so easy to match. If you get the red or teal, thing get more complicated. Maybe you can find a Duplicolor stock can to match? Sold at your local auto chain store. A black swing arm may work to? I don't know how difficult it would be to get a can of touch up from your dealer? If you have to go the route of getting a color match from a auto paint supplier, your talking about $75-$100 bucks for a decent single stage urethane/activator.
 Any advice you need, let me know, no prob. Maybe we could hook up in say, Iowa, half way, right? :D
 Good luck, Dan.
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Ducati Scotty

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Reply #88 on: July 21, 2010, 03:06:46 am
I'm not that picky, it's buried under the bike.  The closest DupliColor rattle can from a Chevy or whatever will do.  I painted my own Dark Monster fender and it came out good enough that no one ever noticed.  Talk to a painter about trying to match Ducati Dark black one day, it's no picnic.

Can we change the name of this thread to 'Gorilla Swingarm Mod avec le 19"wheel'?

And how does it ride with the 19" tire and 18" wheel? :P

Scott


gashousegorilla

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Reply #89 on: July 21, 2010, 03:32:30 am

Can we change the name of this thread to 'Gorilla Swingarm Mod avec le 19"wheel'?

And how does it ride with the 19" tire and 18" wheel? :P

Scott
Yes ,I think we should. It would make things much easier.

But what do dem French words mean ???, You didn't curse at me, did Ya? :D   
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