Cracked swingarm

[Alan Moreton]

Hi Guys.
I know there have been reports in the forum about the swing arm cracking around the bearing housings, but has anyone seen cracking anywhere else on the swingarm?
Whilst I haven't had a chance to fully investigate it very carefully, whilst cleaning my 03 60,000 miler bike earlier today I noticed what appears to be a crack immediately below the right hand side lower shock absorber mount.  Its actually about 15mm long and 5mm below and parallel to the weld.
I'm not sure if the swingarms can be safely welded?  Might the heat generated cause problems with the material strength?    I'd appreciate any thoughts or advice. There are a few swingarms on eBay at the moment so replacement might be the easier option, but maybe those could be cracking too?
The bike has never been crashed (I've had it since new). I do a lot of two up riding and I occasionally have panniers mounted,   I also very occasionally tow a small light weight single wheel trailer that mounts through the rear spindle.  Neither are ever heavily loaded.  Whether any of this has any bearing on the cracking - I don't know.
Regards
Chip.

[KiwiCol]

Sounds like just a bit of bad luck Alan (Chip) Also sounds like it's to do with the original weld / fitment of the lower bracket.  If it were mine, I'd just get it welded up.  They'd have to grind it out first then weld it up & then grind it back to profile.

Be easier for the welder if it were off the bike, but they could do it in place, be harder & messier though. 


Another option would be to bung some metal epoxy in there & see how that goes. They have some pretty good stuff out nowadays.

good luck whichever road you go with it.

[seth]

I've only ever heard about cracks at the pivot bearing housing not anywhere else.
Guess it could be repaired as the standard welding isn't fantastic in that area of the bike .

[Globalrider]

Chip or is it Crack?!
Better check mine - First I've heard of this issue!
Thanks
Stan

[froudy]

If it is a crack, have a word with Harry...He'll sort it for you

http://www.briteworx.uk/

[Mrg]

Checked mine today and all seems  good  so that's ok  but better to have checked thanks for the heads up  Alan 

[Alan Moreton]

Thanks to everyone who has commented. 

I do know of a local specialist welder who I have used to repair an engine case when I was rebuilding my GT380, so I think might seek advice from him.

Your opinions are much appreciated.  I shall do some more investigation and get back to you with the results.

Thanks again 

Al (or Chip)

[seth]

Hopefully it can be fixed
I would get him to check the other side while he's at it as it might be the fact you have a tow bar and pull a trailer adding extra stress to the swingarm where it wouldn't be expected to have any twisting forces on it.

[Alan Moreton]

Hi Seth,

Yes indeed, I have checked the other side and it appears to be fine.  I have also considered that it could be the trailer that might have applied some loading that it wasn't designed for, but its surprising that it isn't the welding that's cracking, its the actually material of the swingarm below the shock mount. The trailer is very light and I never load it with anything more than you could get in panniers. Having said that, the dynamics of suspension movement and loadings are extremely complicated so could very easily have contributed over the 10 years or so I've been towing it.

This morning I have taken the bike over and had the welder take a look at it.  He reckons its could be a relatively easy job assuming the crack isn't any bigger than what can be seen visually.  He would have to apply some considerable amount of heat into the area to do the weld and it could affect the metal structure.  Also he was wondering (as was I) if its an exfoliation type of crack, due to corrosion, as the lip of the crack is lifting and has a dark encrusted edge, - almost as if its bursting apart.  I've seen such problems on alloy aircraft structure in the past.

So - I think I might well go for a second hand swingarm, and then possibly investigate the fault deeper.

Once again thanks for your interest and comments guys.  I'll let you know  how I get on.  I'll try and get some decent photos too, when the swingarm is off!

Regards  Alan.

[seth]

@Alan Moreton
Sounds like your on top of it
Pictures would be good so others know what to check and look for.
As I said before it's not a problem I've heard of before so if it's age related it's something to look for when washing the bike or doing other maintainance on the bike.
Hope you get to the bottom of it and get it fixed .
Good luck

[Alan Moreton]

Thanks again Seth.

This afternoon I called in to a local small welding company who was kind enough to search out his Penetrant fluid and developer for crack detection.  Never been there before yet he still gave them to me on the promise I'd return them.  What a gent!

I cleaned out the visible cracks with a Dremel and bit which removed a lot of flaky metal.   I then cleaned the area with the special cleaner and applied the penetrant and eventually the developer.  The upshot is - there are two cracks!

So - I have bought a swingarm off eBay.  Hopefully it should all be sorted by the weekend!

My camera is not very good, and the pictures I took did not come out very well. The ones that did sort of come out, were taken after the cracks were opened up with the Dremel.  They were nothing like so conspicuous when first spotted!

Alan

[Kiwifruit]

Lucky you spotted that Alan. Thats very cracked.

[Globalrider]

Well Crack - I guess that puts an end to off-roading!!

Stan

[Alan Moreton]

   Yep - no more motocross for me!
The replacement swingarm arrived today. It was in pretty good condition (20,000 miles according to the vendor) although not quite as good as my original (excepting the cracking of course).  So within a hour or so I was back on the road again. 
As it happens - it was just as well I removed the swing arm, as I found the left side needle roller bearing was slightly corroded and would have needed replacement soon anyway!  The right side was perfect still after 60,000 miles!  Strange really as the right side is covered in chain lubricant that you would have thought might have protected it better?  I also took the opportunity to give everything a good clean, polish and greasing.
Anyway guys - once again thanks for your interest and comments.  Kindest regards to you all.
Chip

[Globalrider]

No more Crack - that is good Chip!
Grease probably held in the dirt/grit putting pay to the left side roller bearing.

Shred