crack in the weld on the swing arm

fond a crack on the weld of the swing arm by the chain slider. taking it in to see what the prognoses is, if i have to get a whole new swing arm or it can be welded.

anyone have this happened?

That's the first I've heard on the WRR's. However, I've seen a few break on KTM's and BMW's.

If it's just a small crack, I don't see any reason why a good welder couldn't fix it. However, I would be thinking about it every time I got on the bike and would probably replace it. If for peace of mind only.

Got any pictures?

motokid wrote:

Got any pictures?

Yes! I would like to see pics also.

took it in to the shop and they are going to give yamaha a call and ask so questions? we will see because the bike is three years old and over 27,000 miles on it, hard miles. so thats a factor, and i have my capt. that is a whiz at welding, so again we will see?

i do think about it and i dont want think about when im riding, so of course a brand new one would be i deal.

they are $553.51.


cant bring up my pics?? dont know what it is???

FYI - There is a guy parting out a brand new X on ebay right now. He wants under $300 for the swing arm. Unfortunately it's black. But if Yamaha doesn't cover it you have a cheaper option. I bought a master cylinder from the same seller (bike) and it was brand new. Anyway, another possible option for you.

http://cgi.ebay.com/ebaymotors/WR250X-WR250-X-SWINGARM-REAR-SWING-ARM-WR-250X-WR-250-/110666105027?pt=Motorcycles_Parts_Accessories&hash=item19c436c0c3#ht_6441wt_939

It could be welded if they don't replace it. However, you should seriously consider who does the work. If they do a shitty job, chances are it will end up being weaker than before the fix or distorted so much that you wont be able to use it anyway.

I would really like to see some pictures. Depending on the location and severity, that one on eBay may be close to the price of a repair done by a reputable shop.

Careful with welding a cracked weld, you have to remove the crack with a deep V or it will come back
A freind and outstanding welder did my quad racer swing arm many years ago and every crack came back not long after

thanks trav72 on that swing arm. sent pictures to yamaha, waiting to her back? a new one is the way to go, those always crack again, if not in the same spot, next to it.

why cant i post my pictures

drater wrote:

thanks trav72 on that swing arm. sent pictures to yamaha, waiting to her back? a new one is the way to go, those always crack again, if not in the same spot, next to it.

why cant i post my pictures

Are you using imageshack or photobucket?

Or are you trying to upload from your hard drive?

posting pictures <-- or click this

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there it is! i was able post pics all the time and something changed in my settings i guess?

just looked at that swing arm for sale, i wonder if they are all the same dimension as WRR 08?

0007onWR wrote:

Careful with welding a cracked weld, you have to remove the crack with a deep V or it will come back
A freind and outstanding welder did my quad racer swing arm many years ago and every crack came back not long after

I remember that quad!! You, Bruce and Darryl had the same damned one. Confusing. I saw the crack and now the thing is a forbidden pic.... Damn Drater quit posting porn.

Try hosting it directly on this forum.

How exactly is a cracked swingarm picture a violation of imageshack?????

drater wrote:

just looked at that swing arm for sale, i wonder if they are all the same dimension as WRR 08?

Yes they are all the same. That one in particular already comes with all of the bearings as well. Brand new I might add.

BTW - I have absolutely no affiliation with that seller.

Yes the only difference between that swing arm and your WRR's is the color.

ok lets see if that one stays on there!

ya i think i might be on that swing arm? thanks for that info, black is good, i'll take it rather then paying 550.00

Noob question, how exactly does a swingarm crack like that ? After looking at the WR's and comparing it to the one on my old CBR125R it seems pretty beefy...

That looks fairly severe. That hole in the crater at the end of the weld pictured is a textbook breeding ground for crack initiation but does not appear to be part of your problem. I'd like to see where it goes up top and down below to maybe get an idea of how it started. Once you get it off, if you remember take a few more photos.

ya it stops right there under the chain slider about a 16th of a inch in from the picture.

i know so many guys that have ten year old bikes that they beat and can't even crack them, and this cracks?

Wow! That does look severe! I wouldn't ride with that even if it was welded again. I jump mine all of the time, ride lots of whoops and ST every weekend. There are no cracks anywhere that I can see (I went and looked after seeing your pic). Maybe it was a defective weld?

craigq wrote:

Noob question, how exactly does a swingarm crack like that ? After looking at the WR's and comparing it to the one on my old CBR125R it seems pretty beefy...

Most of the time cracks start because of a discontinuity or stress riser inside or on the surface of the material. Internal discontinuities are usually unwanted junk or voids that get there during the manufacturing process. That hole at the end of the weld in the picture drater posted is a classic example of a surface discontinuity, something the welder should have avoided. Others include undercut at the edges of a weld, contamination in a weld, and even excessive weld. The stresses the part sees as a whole are multiplied at these points which can lead to a crack if the stress gets high enough or it sees enough fatigue cycles.