# Trevor's Triumph
**URL:** https://forums.speedlife.net/t/trevors-triumph/274398
**Category:** Builds
**Created:** [November 16, 2016, 5:38pm UTC](https://forums.speedlife.net/t/trevors-triumph/274398 "2016-11-16T17:38:19Z")
**Posts on this page:** 20
**Page:** 6
### Author:  [@GV1390](https://forums.speedlife.net/u/GV1390)
#### Post date: [February 7, 2017, 8:09am UTC](https://forums.speedlife.net/t/trevors-triumph/274398/101 "2017-02-07T08:09:39Z")
> [@newman](#):
>
> cantelevered
cantilevered\*
🙂
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### Author:  [@L47](https://forums.speedlife.net/u/L47)
#### Post date: [February 7, 2017, 8:39am UTC](https://forums.speedlife.net/t/trevors-triumph/274398/102 "2017-02-07T08:39:24Z")
> [@newman](#):
>
> It would take some fixturing but what if you just cut off the existing mount and made a new complete one instead of trying to join these three pieces. Moving the bearings outboard is definitely a good thing, though, I understand why you want to do that.
The only real problem that I have with that is that the backbone of the frame is the oil tank [OIF] and that pivot housing is REALLY in there. It’s siamesed into the frame a good half inch, so I’d have to open up a good 2"x1" gash into the back of the tank to get it off. I mean, with a welder and some steel anything is possible, I just wonder which method is actually less convoluted?
> [@newman](#):
>
> Is the swingarm bolt for the ducati swingarm smaller, larger or the same size as stock?
Ducati pivot bolt is larger than the triumph. It’s 20mm. It’s really just a shaft with circlip groove in each end. No real provision for any side preload.
> [@newman](#):
>
> Lastly, have you considered building your own swingarm? I think you’re capable. It’s not like the ducati one is a thing of beauty, and it is fairly simple.
>
> In this pic you posted, the only thing that sticks out to me as “ugly” is that square swingarm. Looks like something someone welded up in their garage. A round tube swingarm would look a million times better, and you could make it narrower in the front, which would have a MUCH cleaner look. I suspect the other side looks kind of goofy with the swingarm pivot pushed way out further than it needs to be. Then you could tuck your controls in tighter. I digress.
Actually, yes. I had considered building my own swingarm and then I reconsidered it the other day. And that was a thought I had the other day while looking at that swingarm; “damn that fucker is WIDE up front.” I thought about how far out I’d have to have my rearsets to clear the damn thing. It’s really just _too_ wide. You might have just convinced me.
Having said that, I’ve read that it’s typical to have the cylindrical needle bearings configured with the outer race as the dynamic race, with the inner race pivoting around a static shaft. Should I consider that approach?
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### Author:  [@newman](https://forums.speedlife.net/u/newman)
#### Post date: [February 7, 2017, 10:31am UTC](https://forums.speedlife.net/t/trevors-triumph/274398/103 "2017-02-07T10:31:58Z")
I just typed a big post and lost it.
Late Harley 4 speed transmissions use torrington (needle) bearings in both configurations, dynamic and static cage.
You really want a ground surface with low RMS in order to not tear up the bearings. If the ducati swingarm bolt was originally used with this type of bearing, then no problem, otherwise, you may be screwing yourself.
Is the ID of the triumph swingarm pivot ~1.1085? (Basing that off your press fit sleeve)
Those needle bearings will take zero thrust load, so you will need some provision for that no matter what swingarm you use.
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### Author:  [@L47](https://forums.speedlife.net/u/L47)
#### Post date: [February 7, 2017, 11:08am UTC](https://forums.speedlife.net/t/trevors-triumph/274398/104 "2017-02-07T11:08:32Z")
> [@newman](#):
>
> I just typed a big post and lost it.
>
> Late Harley 4 speed transmissions use torrington (needle) bearings in both configurations, dynamic and static cage.
>
> You really want a ground surface with low RMS in order to not tear up the bearings. If the ducati swingarm bolt was originally used with this type of bearing, then no problem, otherwise, you may be screwing yourself.
Okay, so static/dynamic cage isn’t super important. Noted. Yes, the Ducati shaft is ground/hardened to ride on Torrington bearings from the factory.
> [@newman](#):
>
> Is the ID of the triumph swingarm pivot ~1.1085? (Basing that off your press fit sleeve)
Yes, the ID of the pivot is right around ~1.108". I can’t remember _exactly_ the ID right now, but I believe I planned on a .002" interference. Should I shrink that down a bit?
> [@newman](#):
>
> Those needle bearings will take zero thrust load, so you will need some provision for that no matter what swingarm you use.
The depth of the counterbore in the cups for the Torrington bearings is .002" deeper than the length of the bearing and I’ve got roller thrust bearings with hardened race washers to go between the cups and swingarm. Should only need a few pounds of side preload to keep everything tight.
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### Author:  [@newman](https://forums.speedlife.net/u/newman)
#### Post date: [February 7, 2017, 11:16am UTC](https://forums.speedlife.net/t/trevors-triumph/274398/105 "2017-02-07T11:16:55Z")
I suspect you could go to .003 or even .004 if you torch the mount before you put it in. Since you’re welding it, I don’t think it really matters, just want to maintain the alignment.
I don’t think you need the thrust roller bearings but it certainly couldn’t hurt!
Best type of bearing in my opinion would be a timken tapered roller with the outer race in the frame. No need for any separate thrust bearings or a precision shaft. Going to be a little larger diameter, but worth it for simplicity. Just shove a bolt through and go.
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### Author:  [@L47](https://forums.speedlife.net/u/L47)
#### Post date: [February 7, 2017, 11:38am UTC](https://forums.speedlife.net/t/trevors-triumph/274398/106 "2017-02-07T11:38:47Z")
> [@newman](#):
>
> I suspect you could go to .003 or even .004 if you torch the mount before you put it in. Since you’re welding it, I don’t think it really matters, just want to maintain the alignment.
Cool. Right…in this case the interference isn’t for retention, but merely alignment.
> [@newman](#):
>
> I don’t think you need the thrust roller bearings but it certainly couldn’t hurt!
I didn’t think I really _needed_ them either, but there had to be some type of thrust-safe surface in between the frame and swingarm. It was either roller bearings or copper washers. The bearings were cheap enough.
> [@newman](#):
>
> Best type of bearing in my opinion would be a timken tapered roller with the outer race in the frame. No need for any separate thrust bearings or a precision shaft. Going to be a little larger diameter, but worth it for simplicity. Just shove a bolt through and go.
Can’t believe I didn’t even think of using tapered rollers. You’re right. That would be easier. I could drop to a 15mm ID bearing and my OD would be 35-40mm, so it wouldn’t be _drastically_ larger, and I wouldn’t need a precision shaft as the bearing doesn’t ride directly on it.
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### Author:  [@newman](https://forums.speedlife.net/u/newman)
#### Post date: [February 7, 2017, 11:52am UTC](https://forums.speedlife.net/t/trevors-triumph/274398/107 "2017-02-07T11:52:16Z")
One last thing, if you run the timken setup you will need a spacer between them. Might have to play with spacer length just a touch to get correct preload. I guess alternatively, you could run low torque on the bolt and use a lock tab and no spacer.
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### Author:  [@L47](https://forums.speedlife.net/u/L47)
#### Post date: [February 7, 2017, 11:55am UTC](https://forums.speedlife.net/t/trevors-triumph/274398/108 "2017-02-07T11:55:08Z")
> [@newman](#):
>
> One last thing, if you run the timken setup you will need a spacer between them.
…that rides on the shaft, and prevents the inner races from crushing and brinnelling the rollers and outer races and allows a set amount of static preload? I see what you’re up to. Good looks.
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### Author:  [@newman](https://forums.speedlife.net/u/newman)
#### Post date: [February 7, 2017, 12:00pm UTC](https://forums.speedlife.net/t/trevors-triumph/274398/109 "2017-02-07T12:00:26Z")
The “right” way to do it would be to have the spacer stepped and actually go into the ID of the race, but I don’t think that’s critical, I think you could just use one that’s the correct length, you will just have to align the spacer to the hole in the bearing when inserting the rod.
Here’s a bit of semi-relavant info:
[http://www.shovel-head.de/tech/fahrwerk/starhub\_conversion.pdf](http://www.shovel-head.de/tech/fahrwerk/starhub_conversion.pdf)
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### Author:  [@L47](https://forums.speedlife.net/u/L47)
#### Post date: [February 7, 2017, 12:16pm UTC](https://forums.speedlife.net/t/trevors-triumph/274398/110 "2017-02-07T12:16:37Z")
> [@newman](#):
>
> Here’s a bit of semi-relavant info:
>
> [http://www.shovel-head.de/tech/fahrwerk/starhub\_conversion.pdf](http://www.shovel-head.de/tech/fahrwerk/starhub_conversion.pdf)
That really illustrated your point. I understand completely now.
I like this idea MUCH better than my previous plan.
Thanks, newman.
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### Author:  [@newman](https://forums.speedlife.net/u/newman)
#### Post date: [February 7, 2017, 12:32pm UTC](https://forums.speedlife.net/t/trevors-triumph/274398/111 "2017-02-07T12:32:51Z")
> [@L47](#):
>
> That really illustrated your point. I understand completely now.
>
> I like this idea MUCH better than my previous plan.
>
> Thanks, newman.
Glad I can help. I still really think you should consider making your own swingarm. It could look very slick and really set the build apart. I may be limiting myself to what I take in but in general I don’t see that much custom stuff. I browse bike exif now and then and so many of the “customs” are just littered with bolt-on parts. That and pipeburn are really the only places I browse, though.
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### Author:  [@L47](https://forums.speedlife.net/u/L47)
#### Post date: [February 7, 2017, 12:34pm UTC](https://forums.speedlife.net/t/trevors-triumph/274398/112 "2017-02-07T12:34:13Z")
Oh, I’m going to. I was on the fence about it, and you pushed me off the other side.
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### Author:  [@newman](https://forums.speedlife.net/u/newman)
#### Post date: [February 7, 2017, 12:49pm UTC](https://forums.speedlife.net/t/trevors-triumph/274398/113 "2017-02-07T12:49:56Z")
Build it from stainless and pre-polish it before welding. I know a guy who thinks that looks great. 🙂
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### Author:  [@L47](https://forums.speedlife.net/u/L47)
#### Post date: [February 7, 2017, 11:15pm UTC](https://forums.speedlife.net/t/trevors-triumph/274398/114 "2017-02-07T23:15:02Z")
> [@newman](#):
>
> Build it from stainless and pre-polish it before welding. I know a guy who thinks that looks great. 🙂
That sounds like a gigantic pain in the dick. Hah. I mean, this bike and your 'Knuckle only share the fact that they have two wheels and a motor, but I seriously appreciate all of your engineering expertise. I’ll still fixture up and fabricate a swingarm from scratch, but then I’ll powdercoat it black; only to have absolutely fucking no one ever notice it. Ever. Except maybe you. And others that followed this thread. Maybe.
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### Author:  [@Quattro\_Krant](https://forums.speedlife.net/u/Quattro_Krant)
#### Post date: [February 8, 2017, 6:29am UTC](https://forums.speedlife.net/t/trevors-triumph/274398/115 "2017-02-08T06:29:22Z")
Jr would think it’s quite rad. He informs me EVERY. SINGLE. TIME. we drive past your dads garage, “There’s a motorcycle in there!!!” “Remember when we stopped there and saw the motorcycle!!!” “He has a motorcycle!!!” “He doesn’t have any kids” “Why isn’t he a daddy!!!” And on and on and on.
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### Author:  [@focusinprogress](https://forums.speedlife.net/u/focusinprogress)
#### Post date: [February 8, 2017, 7:50am UTC](https://forums.speedlife.net/t/trevors-triumph/274398/116 "2017-02-08T07:50:40Z")
> [@newman](#):
>
> Glad I can help. I still really think you should consider making your own swingarm. It could look very slick and really set the build apart. I may be limiting myself to what I take in but in general I don’t see that much custom stuff. I browse bike exif now and then and so many of the “customs” are just littered with bolt-on parts. That and pipeburn are really the only places I browse, though.
A “cafe” type build you may be able to appreciate.
> **[Knifemaker's 82 Virago 920 cafe racer](https://www.customfighters.com/threads/knifemakers-82-virago-920-cafe-racer.60761/page-10)**
I followed this along when it was being built and this guys at-home DIY throughout the build continued to impress.
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### Author:  [@newman](https://forums.speedlife.net/u/newman)
#### Post date: [February 8, 2017, 8:03am UTC](https://forums.speedlife.net/t/trevors-triumph/274398/117 "2017-02-08T08:03:09Z")
THE LAYOUT OF THAT FORUM IS HORRENDOUS.
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### Author:  [@focusinprogress](https://forums.speedlife.net/u/focusinprogress)
#### Post date: [February 8, 2017, 8:22am UTC](https://forums.speedlife.net/t/trevors-triumph/274398/118 "2017-02-08T08:22:16Z")
YES IT IS. I followed it elsewhere but couldn’t remember where. had to google and that’s the first place it came up on. My bad.
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### Author:  [@GV1390](https://forums.speedlife.net/u/GV1390)
#### Post date: [February 8, 2017, 10:07am UTC](https://forums.speedlife.net/t/trevors-triumph/274398/119 "2017-02-08T10:07:39Z")
I remember stumbling upon that forum when I was looking at CB919’s, woof! Andy Zion is probably the owner.
Did take this from the following page that Nick linked though:
[](http://redirect.viglink.com/?format=go&jsonp=vglnk_148657715959612&key=a2b9c8d381767486199fd545f3dbe8b7&libId=iyx9nnbn01001ngy000DAcj1qmy0o&loc=http%3A%2F%2Fwww.customfighters.com%2Fforums%2Fshowthread.php%3Ft%3D60761%26page%3D11&v=1&out=http%3A%2F%2Fs1228.photobucket.com%2Fuser%2Ffizzer7%2Fmedia%2FCraigsbay%2Fcustomfighters%2Fgiphy.gif.html&ref=http%3A%2F%2Fwww.customfighters.com%2Fforums%2Fshowthread.php%3Ft%3D60761%26page%3D13&title=Knifemaker's%2082%20Virago%20920%20cafe%20racer%20-%20Page%2011%20-%20Custom%20Fighters%20-%20Custom%20Streetfighter%20Motorcycle%20Forum&txt=%3Cimg%20alt%3D%22%22%20src%3D%22http%3A%2F%2Fi1228.photobucket.com%2Falbums%2Fee454%2Ffizzer7%2FCraigsbay%2Fcustomfighters%2Fgiphy.gif%22%20border%3D%220%22%3E)
I do like that rear sub frame portion though.
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### Author:  [@Quattro\_Krant](https://forums.speedlife.net/u/Quattro_Krant)
#### Post date: [February 8, 2017, 3:26pm UTC](https://forums.speedlife.net/t/trevors-triumph/274398/120 "2017-02-08T15:26:53Z")
A Virago is _THE_ bike I picture when I think of the ugliest 80’s motorcycle in existence
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