Author Topic: RM125X (1981) Swingarm Alloy type (and “Full Floater” bearings)  (Read 457 times)

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Offline skypig

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The swingarm has a crack through an existing weld.
Anyone know what the alloy is? (6061?) or the likely “series”. (6000?)
Or what sort of filler rod I should use with my TIG.

Also any clues as to the best replacement bearings, top and bottom of the vertical swingarm mounted “Full Floater” linkages.

Thanks for any clues.

Offline GMC

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Re: RM125X (1981) Swingarm Alloy type (and “Full Floater” bearings)
« Reply #1 on: March 10, 2021, 08:11:07 PM »
Choosing filler rod can almost be as bad as asking what 2 stroke oil to use ???
There are few different filler rods you could use but the short version is you will be okay with 5356

As to what alloy the arm might be is a good question, I have welded 6061 & 6060 components with 5356 and had them anodised without problems however I once repaired a early Suzuki arm with 5356 filler and also had it anodised however the bits that I welded came out in ugly dark blotches which suggests to me they aren't 6061

You will need to remove the anodising well clear of the section to be welded then your dilemma will be do you leave it like that or remove all the anodising so the whole arm looks the same. Any attempt to re anodise it will likely produce blotches as above so I would recommend a clear coat.
Also try not to put too much heat in as most structural alloys gain there strength from heat treating and too much heat will rob strength.
Use a heat gun to put some mild heat in then use high amps so you can get in quick to the area and avoid heat soaking the whole arm
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Offline skypig

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Re: RM125X (1981) Swingarm Alloy type (and “Full Floater” bearings)
« Reply #2 on: March 11, 2021, 10:03:11 AM »
Legend!!

Great info, that makes sense, and comes from experience.
(We are blessed to have a forum like this, with members like GMC!!)

Thanks.

I was once riding really fast, and a guy passed me with “Castrol” stickers on his bike. So that must be the best 2 stroke oil!!
« Last Edit: March 11, 2021, 10:23:59 AM by skypig »