Author Topic: Bronze Swing Arm Bushings For C5?  (Read 25930 times)

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qgolden

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Reply #60 on: July 11, 2010, 01:02:51 am
Not that we are not interested in what you are doing, and want you to document every detail, leaving no stone unturned in your quest for improvements, ...but...Look at which picture has had the most hits!      ;D
Any other Enfields in New England?


gashousegorilla

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Reply #61 on: July 11, 2010, 04:28:27 am
Not that we are not interested in what you are doing, and want you to document every detail, leaving no stone unturned in your quest for improvements, ...but...Look at which picture has had the most hits!      ;D
Yea right? Geeeez,swing arm schming arm. Who cares. All you guys think about is sausages and side cars? :D  
 Couple more coats of paint, and I'll post some pics of the modified swing arm. Or maybe not, maybe I'll  just post a pic of some tricked out Trike with a deep fryer on the back. Geez  La- Weez!
« Last Edit: July 11, 2010, 04:38:22 am by gashousegorilla »
An thaibhsí atá rattling ag an doras agus tá sé an diabhal sa chathaoir.


gashousegorilla

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Reply #62 on: July 12, 2010, 05:28:45 am
OK boy's , here you go, strong and beefy modified C-5 swing arm. 1" pipe welded in. With 1/4" flat stock fitted and welded in center of pipe for good measure. Painted up and ready to go. Pivot bolt spacer packed with Triple guard super blue Evinrude grease. Put it all back together tonight, and took her for a quick test.All in order so far, same results as last test with pipe tacked in. 10-15 mph improvement in stability. Stable cruising up to 70mph, after that front end starts to feel light and squirrely. Time to move on to the front end. 19" wheel , perhaps. maybe a Damper, maybe even wider bars?
An thaibhsí atá rattling ag an doras agus tá sé an diabhal sa chathaoir.


ace.cafe

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Reply #63 on: July 12, 2010, 01:34:41 pm
If I remember correctly, the swing-arms from the Enfield twins like the Interceptor had braces like that in them.

It looks like you did a nice job.
Love the Incredible Hulk holding the swing-arm!

For what it's worth, I'm getting some spidey sense tingling that is making me think that you are getting drag-induced lift of the front suspension, making the bike light in the front at speed.
Try leaning forward a bit, and see if you can reduce the "parachute effect" of your body against the wind, and see if that helps the stability some. Maybe you need lower bars.
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gashousegorilla

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Reply #64 on: July 12, 2010, 03:32:11 pm
If I remember correctly, the swing-arms from the Enfield twins like the Interceptor had braces like that in them.

It looks like you did a nice job.
Love the Incredible Hulk holding the swing-arm!

For what it's worth, I'm getting some spidey sense tingling that is making me think that you are getting drag-induced lift of the front suspension, making the bike light in the front at speed.
Try leaning forward a bit, and see if you can reduce the "parachute effect" of your body against the wind, and see if that helps the stability some. Maybe you need lower bars.
Thanks Ace.  Very intesting about the twins, I was not aware of that, but it would make sence. Also a very good thought on the parahute effect. Us ton up boys are not use to such peculiar phenomina , being all hunched over on our clubmans,like you see below :D Scott any thoughts. ???  Makes sence to me.at least a contributing factor. I read a good peice on wiki about bike stability, it said the most critical part of the bike's stability is rider input.
« Last Edit: July 12, 2010, 06:29:23 pm by gashousegorilla »
An thaibhsí atá rattling ag an doras agus tá sé an diabhal sa chathaoir.


Ducati Scotty

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Reply #65 on: July 12, 2010, 04:19:44 pm
With that in mind, wider bars would only amplify rider input.  Stick with the stock bars and practice good form: grab the tank with your knees and hold a very light grip on the bars.

Still, I think that both drag and short trail are probably also big contributors to current instability.  Leaning forward is an easy and cheap experiment.  Also, make sure the tank is full for your next run.

Scott


gashousegorilla

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Reply #66 on: July 12, 2010, 04:43:56 pm
How bout the effects  of a cinder block tied to the down tube? And it's aerodynamic effects ?  :D
« Last Edit: July 12, 2010, 04:46:23 pm by gashousegorilla »
An thaibhsí atá rattling ag an doras agus tá sé an diabhal sa chathaoir.


Ducati Scotty

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Reply #67 on: July 12, 2010, 05:41:41 pm
Oh, and the fact that there was no gusseting or reinforcement to start with seems weird.  I think I'd be apt to do this mod just for peace of mind.

Scott


gashousegorilla

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Reply #68 on: July 12, 2010, 07:40:01 pm
 Seriously, I would like to thank ALL of you guys for your positive input with this issue. I think WE produced a pretty good  improvement in the high speed stability of my C-5.Theres still room to go, but it worked so far in my case.
  In particular I would like to thank chinoy,who recognized early on the weakness in the swing arm design, when many of us were on the fence or looking else where. Chinoy knows his Stuff, He's a cafe builder/mechanic, and knows his way around a BikeAnd must agree that a bike should be stable to it's maximum claimed top speed. Or a little further. We westerner's must remember,that for us by and large, motorcycling is a hobby or pass time. We like to think of ourselves as "Biker's" , "Rocker's, "Ton-up Boys", or whatever.Some of us are, some are not. Whatever your involvement it's cool. For the people who live in the East, Far East, and other parts of our world, motorcycles are as mundane as our SUV's and Minivans with the magnetic soccer Ball on the back.In otherwords they Live on their bikes, and could teach us a thing or two.The sharing of knowledge is a gift and should be treated as such.
 Also in particular DucatiScotty, a.k.a The professor ;D Who I think is a Closet Engineer, but ain't Say'in, and Ace-Cafe, who with a name like that must be a Rocker, for there useful tech input.
 Thanks Boy's, Dan.
« Last Edit: July 12, 2010, 08:00:06 pm by gashousegorilla »
An thaibhsí atá rattling ag an doras agus tá sé an diabhal sa chathaoir.


r80rt

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Reply #69 on: July 12, 2010, 08:29:46 pm
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?
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qgolden

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Reply #70 on: July 12, 2010, 08:37:48 pm
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
Any other Enfields in New England?


ace.cafe

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Reply #71 on: July 12, 2010, 09:06:05 pm
The aero drag on the rider, or drag on anything high up on the bike, causes a rearward pressure that is translated into lift at the front end. This is because that drag force becomes a torque moment around the rear axle, and the vector is up and back in direction. It's like it's trying to make you do a wheelie.
The faster the speed, the higher the aero drag, and the more the front end lifts.
As the front end lifts, weight distribution is transferred off the front wheel to the rear wheel, resulting in front end instability.

Reduce aero drag, go slower, or lower the location of the aero drag, and you'll get less lift.
Aero drag increases as a cube relationship to speed, so the aero drag increases alot faster than your road speed does.

The rider is perhaps the biggest aero drag component on the bike. Lowering and streamlining the rider can have a profound effect on many aspects of the bike's performance, including acceleration and top speed, as well as load on the engine at any speed.
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Ducati Scotty

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Reply #72 on: July 12, 2010, 09:46:22 pm
You're welcome Gorilla.  Strictly speaking, I was failing out of engineering school when I switched to computer science as all good failing engineering students do :)

Seriously, not being an RE owner yet I hadn't taken a close look at the swingarm.  I think my 1977 Hnoda XR75 dirt bike had more swingarm bracing than the stocker you showed.  I seriously would pull that off and get something welded in at the first convenient time.

Just curious, why the piece of flat stock welded in the middle of the brace?  Better torsional rigidity?  Just easier to cut and shape the fish mouths on the ends of the new piece?

Scott


gashousegorilla

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Reply #73 on: July 12, 2010, 10:28:39 pm
Well I hope your old professors are reading this thread Scotty ;) And yes to both. Just easier to fit and get correct, Things love to move around when you weld. Because the stock swing arm springs open so much, it take;s some tweaking to get the dimensions right. Still be able to get the wheel on OK, but not too much stress on the bearings,etc.I might do it different next time with a jig, but hay this is the first one.
An thaibhsí atá rattling ag an doras agus tá sé an diabhal sa chathaoir.


Ducati Scotty

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Reply #74 on: July 12, 2010, 11:19:35 pm
Yeah, would be good to measure the rear wheel width, maybe add 1/8" -1/4" or so, and jig it that far open.  Still, things move when they get hot unless you want work like a body panel welder:  weld 1/8" of bead, let cool completely, repeat until done.  Too much time.

Scott