Cracked Swing Arm

[Anonymous]

I dont know how Tony is going to weld it? Cold, hot, dont know MTK.

Yeah it was longitudinal BC, so with a bit of weld it should be good for a long time yet.

[Jeffrey SmithMember]

Welding cold won’t cause brittleness on aluminium (it is aluminium isn’t it?)unless it is a particularly exotic type which I don’t believe swing arms are, if anything it would cause a soft spot as it is annealing the parent material and the filler material is likely to be softer as well. In any case the swing arm will be fine after repair Dan.

[BrettMember]

DanD wrote:

Quote:

I pulled the swing arm out this arvo and it definately has cracked. Not a big open gaping crack, just a small hair line, not even wide enough to get a stanley knife blade in. I think some of the problem has been the chain slider has been rubbing on the swing arm which has eroded a bit of the swing arm and the crack has appeared.

I spoke to a mate at Yamaha,this is his thoughts:
“No very unusual I have seen some race bikes crack but only as a result of the chain wearing through the slider and carving up the swing arm reducing structural integrity- never seen one crack for no obvious reason”.

Get your hands on some crack detection spray, and it will show it up easily.

But a properly pre-prepared weld should be quiet ok.

Cheers
MacKa….

[Author]

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