All 2st WR300 snapped swinging arm, pics inside!

Hi all,

My mate snapped his 2009 WR300 swing arm around the pivot bolt. He only noticed after landing a double on his EnduroX track when the suspension started creaking!!! Could have been nasty!

Does anyone know what other bikes / years WR or maybe CR swing arms fit please? The part number from his swing arm is 2008-44-NV-8000H1149. I have searched the site and seen this once before but no clear answer to what does or does fit.

We are in the UK so if anyone has one to sell please get in touch.

Thanks.

reckon those chain wear marks wouldn't have helped any(in fact Id say they are the culprit by creating weak spot then transferring stress to other side-notice the crack/split right in middle of smaller wear point where alloy thinnest) but regardless that is nasty! beyond buffing out id imagine. anything post 2000 cr/wr would fit I think but someone will chime in with specific models. keep an eye on chain sliders on next one

Wow, yeah keep and eye on those chain guards they are much cheaper than swingarms!

I'm off to check my chain slider right now!

likely due from lack of grease/binding bearings. were the bearings dry?

I'm curious to see what the swing arm bearings look like. The races in the first photo don't look great. I wonder if that could also have been a contributing factor?
Could they have seized and peeled open the swing arm.

I once had a countershaft bolt break on my '98 250. It had the 6 speed tranny that uses a bolt instead of a circlip. Any way, the sprocket slipped off the shaft and the chain pulled the sprocket into the swing arm and peeled it open kind of like yours. This also happened landing a big jump, it locked the rear wheel and I almost went over the bars. What I wanted to say was I know a good welder and I had it welded and it was good for several years until I retired the bike after racing it for 8 years. Everything on the bike was wore out but the swing arm held up. Mind you I only broke one side. Getting it welded may not be a safe choice if you're riding extreme obstacles and big jumps. Just wanted to relay my experience. Also the chain wear may rule out that solution any way.

Best of luck.

you are correct palito in that binding force is a big contributor. the older swede bikes were common to crack like this due to neglect and seizing. i had two of these swingers welded at work and they have held up fine.. i leave the bearings in place when being welded to help keep the bore round. i try to "vee" out the crack as much as possible and TIG it up! not saying its ideal but both have held up quite awhile

The bearing races to do look very dry and crusty add that to the obvious neglect of the chain slider and it looks like lack of service is the culprit.

I would agree with 'lack of service is the culprit' because I had a look at my bike last night and my slider was good, and even if I didn't have a slider that kind of wear would not be likely with proper chain adjustment. From the picture the wear is on the bottom of the swing arm indicating too much slack in the chain.

Get a good o-ring chain and keep it adjusted properly.

typical take it out, ride the pants off it, put it back
this is a clear case of lack of maintenance
when you see the chain marks and the dry bearing, it's self inflicted

back to the point more than likely many years around that will use a similar swingarm, you will need to help him with some measuring
Husky was not quick to change what wasn't broke, I mean what still worked
wow that was an interesting and not on purpose point

The bike belongs to my mate his a farmer so it got farm maintenance aka nothing. The bearings were dry as a bone. I can see the problem and we have given him plenty of stick about it but also am trying to help him out.

so the "old" line is
i'd love to help you out, which way did you come in

buy a new arm! it can be repaired, but it's the swingarm and its a pretty important part of the bike. highly stressed item. NEW would be the right thing to do.

If you decide to scrap the swingarm (which I would recommend), cut it apart and post up pictures of the fracture surfaces. They can tell you a lot about what happened.

Hay johnny you ventured over from the glc crew? Any way that swingers shagged best sell the bike in bits or keep saved search on fleabay for one.
Coincidence or what i had a counter shaft bolt shear on my 6speed 360 didnt mash the swingarm but put me out of the trial i was set for silver on sad sad times.
If you find out a 250 husky swingarm fits i know where theres one cheap.

Johnny never asked why it broke but he got plenty of answers.

If you decide to cut it up, don't ... Send it to me; I'll pay the shipping and drink the MAX numbers of RedHorse beers(3) that I can drink when it arrives.

Yes I have. What year and model bike is the 250 swing arm from please?

I know why it broke. My bike wouldn't suffer this problem

Wr 250 1999