Swing arm bent among other things

[Striker1423]

This bike's been crashed at least once in its life (no it wasn't me thank God). As evidenced by the slightly out of round headlight bucket, scraped up front turn signal, out of round tachometer mount, etc.

When you get to the rear wheel, the adjuster slot of the swing arm on the right side is just slightly bent in. Now, I figured the shock mounts were tweaked a bit as the left side lined up pretty much ok, but the right side needed the swing arm compressed like a 1/4" to line up with the hole. But, I always thought the sub frame up top was bent as the rear fender never seemed to line up properly with the wheel. Until I bent down and just looked at it for half a minute, I was like well it's tweaked. https://imgur.com/gallery/BAXtxP2

Any suggestions on how to check what is and isn't bent elsewhere? The handlebar mounts seem tweaked, I don't know how to check that other than to try and take them off and look straight down the bolt section. Might the top triple clamp be bent? The swing arm for sure is tweaked, so do I risk an ebay special, or does anyone here possibly have a straight one? (I can post a WTB, just figured I'd add it here too.)

Thanks as always gents.

P.S.
I said tweaked enough times I suppose my bikes a tweaker!  . I'll see my self out...

[m in sc]

check level across the swingarm pivot (take arm out, put shaft in check with digital level. then check to see if neck is 90 degrees from that) obviously don't move frame between checks.



also, you can put hosted images in posts. Just sayin..

[Striker1423]

From what I can tell this swingarm is just about a 1/4"  out of level. The bushings etc are all still in tact so that's good. Is it something I can straighten or should I shoot for a swingarm on ebay? One looks straight and isn't a lot.of money but who knows.

Here's one: https://www.ebay.com/itm/232494938372

Here's another: https://www.ebay.com/itm/351739008834

[rodneya]

Im pretty sure that something else on the frame would have bent before the swing arm.
Take it off the bike and check what the problem really is before ordering parts is my advice

[Striker1423]

I'll get pictures of it, it's off the bike now. I'll get a good look at everything under the bike too.

[m in sc]

Im pretty sure that something else on the frame would have bent before the swing arm.
Take it off the bike and check what the problem really is before ordering parts is my advice

i'm not, i've seen bent arms come off straight frames. like said above, check the pivot holes (with swing-arm pivot in holes) then check for it to be perpendicular to the neck. that will tell you pretty much all you need to know.  the arm is obviously fucked.

[RDFL]

250/350 arms are a lot cheaper on ebay.

[Barrie]

In the U.k we have a system called motoliner , the whole bike gets placed in a fixture and is checked and straightened, I have used this service in the past and it works a treat, have you nothing like this your side of the pond?


http://www.motoliner.com/

[Dvsrd]

Are we talking about an RD or LC swing arm? If it is a stock RD arm, I would try to straighten it.
I assume "tweaked" means twisted, as in wheel axle and swing arm bolt are no longer parallell.
To check that it is straight after straightening, use a flat surface and v-blocks, or just some machined blocks under the pivot bolt and wheel axle. Pretty easy to check.
A stock 70s swing arm and frame would be made of fairly low grade and ductile steel, so should be safe to straighten. And the manufacturing precision may not have been that high in the first place either. Just give it a shot.

[Striker1423]

I put the swing arm bolt back in the bike and checked it level to the floor to verify it was indeed sitting level and both the floor and bike matched level across.



I put the swing arm on my bench and  leveled it on the bench with various implements and a nice long steel rod i have that is straight. Once the rod was level at the rear adjuster slots I took a look at the front of the swing arm.



The front of the swing arm was hovering off the bench a few mm's. So, I took a picture of that here:



I then held the front of the swing arm to the bench where it was hovering and the result is here: It's not off by a lot, but it is bent.



 

[m in sc]

need to make sure the side of the neck is perpendicular to the floor. if so you're good on the frame.  also check across the top rails where the shocks mount.

[Striker1423]

I checked the neck as best I can and it seems level as well. Was able to straighten out the handlebars as the mount was simply knocked a bit out of alignment. Ordered a supposedly straight swingarm and willnsee.how ot works out.