Tweaked Jackpiner Swingarm

[Doug Bridges]

On my 73 Jackpiner, the swing arm is tweaked. Looking at it from the rear the wheel is tilted to the left side. Enough so that the tire rubs on the left side top shock mount bolt/nut when it is bottomed out. I am wondering how common this is with these bikes. I am also wondering if there is any chance of bending it back ( and if so how?) or if I should just thow it away and look for another. Thanks for any help on this subject.

Doug Bridges
73 Jackpiner

[firstturn]

Doug,
  We will see what others have to say and then lets talk.  I will be traveling today, but try and call you tomorrow.  Don't throw it away.

Ron Carbaugh

[thrownchain]

Is the frame "tweeked" or is the swingarm bent?? or a combo of both??

[Doug Bridges]

I am pretty sure that it is just the swing arm that is tweaked. I remember that swingarms on some of the early Japanese bikes would do this just from hard rideing and metal fatigue. I don't know what caused it on this Jackpiner. It was like that when I got it. It could have been crashed hard, but the frame looks OK. It is rideable but I would like to make it right.

Doug Bridges
73 Jackpiner

[rob w]

(Bike resting on box type stand) With the swingarm mounted to the frame, and the rear wheel and shocks removed. A strong guy with gloves on could bend over the back of the bike - pushing down on one arm while pulling up on the other, would be able to twist it back straight. (making distance between shock mounting holes equal on both sides) Or you can block one side (either below or above) and focus your strength to just one side.
Bob W

[firstturn]

Do what Rob suggested, but just use a 2X4 and push down on the high side and the opposite on the low side using one side to work against the other.  Very simple.  if you need a picture shoot me an email.

Ron Carbaugh

[Doug Bridges]

OK, That seems really simple. I didn't know they could bend that easily. I am not a big guy so I will probably go with the 2x4. Thanks for the info guys. I will give it a go this weekend and let you know how it turns out.

Doug Bridges
73 Jackpiner

[brian kirby]

I'm glad you asked this question, I have a second Berkshire project that has a similarly twisted swing arm.

Brian

'72 Berkshire

[Rocketman]

quote:Originally posted by firstturn

just use a 2X4 and push down on the high side and the opposite on the low side using one side to work against the other.  Very simple.  Ron Carbaugh

Good old fashioned trailside engineering.

72 Six-Days

[Doug Bridges]

I did what you guys said tonight and now my Jackpiner swing arm is strate as an arrow. if we are picking teams I want the guy who can do this with his bare hands on my side. For me, I had to use a five foot digging bar while my wife and myself held the bike still I twisted the bar as hard as I could and it did the trick. Thanks again for the tip!:)

Doug Bridges
73 Jackpiner

[firstturn]

Doug,
  You are in luck.  There are two guys up in the Northwest that could do that trick.  One is Big Jon McLean and the other is Thom Green.  These guys are great guys and they can Ride.  Glad it worked.

Ron Carbaugh

[Doug Bridges]

I hope to meet these guys someday.

Doug Bridges
73 Jackpiner