Author Topic: I hope my frame is not bent  (Read 460 times)

Offline ray bear

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I hope my frame is not bent
« on: June 17, 2026, 03:48:04 AM »
Rebuilt the Koni 7610 dial a ride on my Eldorado only to find they wouldnt go back on without a fight, the shock mount bolts from left to right are 2mm different in spacing , this has never been a problem or I didnt notice with the old worn shocks , I fitted the shocks to find that the axle bolt is now a tight fit so placing stress on the swing arm , I can re adjust the pinion to rectify but that doesnt fix the problem of different mount bolt spacing , mount bolts are straight so is it swing arm or top frame rails that are 2mm out , Im hoping its swing arm as I can replace or try and twist it back to square, if its the top frame rails  I think its beyond me heres hoping .
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Offline guzzisteve

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Re: I hope my frame is not bent
« Reply #1 on: June 17, 2026, 06:47:03 AM »
Loosen 4 nuts on swingarm that hold rear drive. Insert axle then retighten 4 nuts to 23ftlbs. This should help.
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Online John A

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Re: I hope my frame is not bent
« Reply #2 on: June 17, 2026, 11:15:46 AM »
Loosen 4 nuts on swingarm that hold rear drive. Insert axle then retighten 4 nuts to 23ftlbs. This should help.





Yep, you’re sposed to tighten the axel before the four mount nuts that hold the drive. Are the shocks still the same length?
John
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Offline ray bear

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Re: I hope my frame is not bent
« Reply #3 on: June 17, 2026, 06:04:09 PM »
Thanks for your input guys appreciated  but I know how to align the axle , the frame or swing arm is bent by 2mm and I dont know how to determine which one it is so I think the easiest way might be to look for a good swing arm and replace it and see if that corrects the problem , I do not re align the axle to compensate for a frame misalignment I want to rectify the problem , to wrongs dont make a right 
« Last Edit: June 17, 2026, 06:24:57 PM by ray bear »
73 V7 sport
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68 BSA rocket 3
74 Norton Commando
78 Honda CBX 1000
47 HRD vincent Rapide
XT 500 Yamaha
76 Convert
84 FLHX limited edition electra glide

Online DoubleGuzzi

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Re: I hope my frame is not bent
« Reply #4 on: June 17, 2026, 06:42:34 PM »
Just some ramblings..
Get a spirit level or two and a plumb line.
Put bike on centre stand and remove the seat.
Before the rear frame rail starts i.e. near to the rear of the tank, place a spirit level across the frame rails.
Shim the centre stand until the bike is level, side to side.
Using a plumb line, measure the height of the mounting points, from the deck/ground.
If the top mounts are different, then it's the rear frame rail(s).
Likewise, if the lower ones are different, then it's the swingarm and/or bevel drive.

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Online John A

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Re: I hope my frame is not bent
« Reply #5 on: June 18, 2026, 12:36:59 PM »
It’s not too uncommon for the bevel box flange to be bent . I’ve seen some race bikes with extra gussets on them. I made a jig to true up a swingarm after I cut them and welded in a plate to make clearance for a wider tire . I remember that the swingarms were hard to bend. I’ve since used that jig plate for another project, it was 1/2” steel with mounts that incorporated pins that went into the bearings and various reference points so it was big and heavy. I used a machinist square to check the flange and with the bevel box attached I could check it for twist using the exposed wheel drive as a reference. If it needed correction I had to use heat and it was a big project. If you strip the rear down to the frame and on the center stand get it perfectly level using the oil pan for a reference on a flat surface you can measure from and with a square and plum bob be able to see where it’s off. You got to take it apart to change the swing arm anyway. Getting a flat spot to set it on is the hard part.
John
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It is easier to fool people than it is to convince them that they have been fooled-Mark Twain
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Offline ray bear

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Re: I hope my frame is not bent
« Reply #6 on: June 18, 2026, 07:18:31 PM »
Thank you all , after a whole day of spirit levels engineers squares string lines and head aches I have rectified my 2mm discrepancy and the obvious was the difference in trueness from the swing arm bearing support tube to the axle spindle . secured swing arm in press and with large bar over and under arms proceeded to twist the legs  with the how much being the worrying part , replaced in bike and on first attempt bingo has all lined up with axle , swing arm and upper frame tube and seat loop behind tank all true with each other  and shocks went straight on without having to compress one to get it on  and the axel has always been an easy 2 finger  fit which I thought was good   after final drive adjustment but now it falls in and out so next test  to see if the bike corners better. Thanks for all help and ideas
73 V7 sport
73 Eldo police special
68 BSA rocket 3
74 Norton Commando
78 Honda CBX 1000
47 HRD vincent Rapide
XT 500 Yamaha
76 Convert
84 FLHX limited edition electra glide

Online cliffrod

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Re: I hope my frame is not bent
« Reply #7 on: June 18, 2026, 09:17:34 PM »
That’s great news to hear. 

The HD factory manual (for the older bikes like shovelheads and such) recommended protocol in such frame & fork situations are to apply similar brute force methods to rectify out-of-spec frames and such..    Obviously, the same procedures work for other marques, too.

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Online Gusable

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Re: I hope my frame is not bent
« Reply #8 on: June 18, 2026, 09:28:36 PM »
That’s great news to hear. 

The HD factory manual (for the older bikes like shovelheads and such) recommended protocol in such frame & fork situations are to apply similar brute force methods to rectify out-of-spec frames and such..    Obviously, the same procedures work for other marques, too.

Like smith and Wesson armory school! A 8 lbs lead hammer will fix all kinds of issues lol
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