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I Have A Bent A Arm.


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Well, I got my banshee on the shop floor today. Only to find that my upper left a-arm is sorta bent. Its like its pushed to the rear. I noticed when I first put it on that the left shock would barely clear, around .100", while the other side clears by about .375" After putting the front tires on and setting it on the floor, it leans in about 3 degrees. Its not like a Banshee-X custom camber -15 degree set up.

What I was wondering is:

 

Is this going to affect my handling?

 

Is it just going to corner like a mofo to the right, and just regular ol handling to the left?

 

Is there a chance its going to put enough pressure on my spindle to fatigue it?

 

Is there anyway I can straighten it? They are chromed, so I really don't want to apply heat or hammer. I was thinking of wrapping it in a towel real thick like, and using my 3" ratcheting strap or something to "persuade" it forward about .250" or so.

 

Should I just leave it alone? I plan on fabbing a-arms in the near future anyway, so I don't want to buy anything else unless I have to.

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Well, I got my banshee on the shop floor today. Only to find that my upper left a-arm is sorta bent. Its like its pushed to the rear. I noticed when I first put it on that the left shock would barely clear, around .100", while the other side clears by about .375"  After putting the front tires on and setting it on the floor, it leans in about 3 degrees. Its not like a Banshee-X custom camber -15 degree set up.

What I was wondering is:

 

Is this going to affect my handling?

 

Is it just going to corner like a mofo to the right, and just regular ol handling to the left?

 

Is there a chance its going to put enough pressure on my spindle to fatigue it?

 

Is there anyway I can straighten it? They are chromed, so I really don't want to apply heat or hammer. I was thinking of wrapping it in a towel real thick like, and using my 3" ratcheting strap or something to "persuade" it forward about .250" or so.

 

Should I just leave it alone? I plan on fabbing a-arms in the near future anyway, so I don't want to buy anything else unless I have to.

Stan are you sure its the arm and not the upper shock mount? or the frame at the arm mount? you could probally align it out and make it ride ok, ive bent knuckles and been able to align it out..if it is the arm i opt for trying to tweak it back, off the bike of course....thats what i dont like about lonestar type fat arms and axles they are the last thing to bend most times......

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Stan:

Something else you may want to look at is the lower a-arm. Take some x measurements from side to side off of common areas. Check the top and bottom. If you have a way of holding the bike down or to something (from the rear) then I would use a strap and maybe a come-a-long and "give it a tug". Or if you know anyone at a bodyshop that will let you use their frame machine for a few hours.... Chain it down and give it a yank. Sometimes it helps to give it a tap w/ a hammer while its under pressure from the pull to lock the steel molecules in that position. Dead blows work great so you dont ruin the finish/chrome.

 

Duece is right... Everyone puts on these big badass parts. Normally the weak link in an accident. Now that weak link is replaced, the weak link is now moved to the frame or other more expensive parts

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Everyone puts on these big badass parts. Normally the weak link in an accident. Now that weak link is replaced, the weak link is now moved to the frame or other more expensive parts

i have LSR a-arms, steering stem and axle on my desert bike but i run light softer jd perfomance arms stock stem and axle on my mx bike a friend asked me why i dont at least put my lsr axle on my mx bike....i told him just what Walt said, besides i like the stock width with offset rims, when i do eat it (and i will) i dont want to tweak my frame (again, i learned the hard way once) he kinda shrugged it off, well he's out long jumping and bailed off, calls me up and ask's to borrow my sawsall, i bring it over and his bikes sitting there with a perfectly straight LSR axle and a twisted swing arm that we had to sawsall from where it mounts to the frame and sheered his shock off where it mounts to the swing arm, he replaced the swing arm and shock but couldnt get it to mount up cause his frame is slightly tweaked..now he's saving for a roller...i wanted to say i told you so, but didnt have the heart to.......You lose a little bling, but wont bend your Swing......

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I'm gonna take some time today and do a couple of things:

 

I'm going to see if I can weasel a protractor or a small square in the upper a arms on both sides to see how far one is out compared to another in relation to the mounting/pivot tube, and the rear tube. (the one that is closest to 90 degrees)

 

We looked at the knuckle, but we can't really tell if its tweaked at all, and there is a chance it got bent when I wrecked, but most of the damage i.e. my taco shaped rim and busted a-arms were on the RIGHT side, not the left. The left side was mostly ok. (yeah it was a 1 wheel verticle landing)

 

I am also going to take a look at the shock mount, and a arm mounts, to see if they are tweaked a little.

 

Something else I am planning on measuring with a protractor is the angle in relation to the bottom a arm (across both tubes) to the front portion of the upper a arm on both sides.

 

When I received the frame from K&K, I went over it, and saw no cracks in the paint anywhere. It had the usual wear and tear, but I didn't really see any stress marks anywhere. I checked it again after I scrubbed it just before I sent it to powder coat.

 

I spun my knuckles, and axle between dead centers on my grinder after I disassembled my banshee last year, and they weren't out at all, so I don't think my spindle is the problem.

 

I kinda wish I would have mocked this thing up before I sent everything to chrome. The damn chrome on the a arms was more than the a arms themselves <_<

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We figured out how were going to fix whats wrong.

The a arm is a little tweaked. Both by protractor and measurements and some geometry/trig its bent around 2-3 degrees towards the rear using the pivot point as a reference. At a round about measurement of 7" from the center of the pivot, every 1 degree is .122". Its out around .250-.300.

 

What we are going to do is this: We are going to make some blocks with holes in them the same size as the inner diameter of the pivot, and weld them to our welding table. Gonna take all the guts out of the pivot and put in a shaft about -.001 smaller than the ID of the pivot, and put it through the holes in the blocks on the welding table. Then weld another block about 3 inches behind the a arm, near the end where it starts to radius. Then we are going to stick a nylon block between the a arm and our PortaPower. With the PortaPower pushing on the steel block, and the nylon block it should push that thing right where we want it. We hope to hit it, but I guess we'll see.

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Stan:

If I was never in your position right now I woulda said HUH?? You wanna do what???!?!?

Fo what you need to do and as much as you need to "adjust it".... that shouldnt be too bad. What brand of A-arms are those? I remember the frame you got from K&K and I remember that thing being very clean.... I doubted it was the frame in the first place... but ya never know :)

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Oh I didn't mention that I got stock A arms off of Ebay for $95 in march of this year.

Basically I'm clamping it down with the pivot tube and pressing the rest of the a arm forward with hydraulics. Its either going to work or it isn't. It only needs to move about .250"

 

I am one happy SOB that I have a machine shop right now. Hell when I bought my ATV stand last weekend I needed a machine shop to get the damn thing working right.

 

I didn't suspect the frame either because when I got it I sat it on the floor, and it rocked about .125 or so, my other frame that got trashed moves .500 or more. I'm gonna have a serious project on my hands the next time that thing comes out of storage B)

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