I hadn't even made it to the powerlines on the red trail. I was riding uphill on a short, steeper section, when "bang!" and the bike goes all wobbly in the back. I powered up the last 20 feet, then stop and see the right swingarm sticking out about 4". It cleanly snapped off, there were no impacts or jumping or crazy riding, so I was pretty shocked. The bike is a 3-month old Cannondale Rize 3 Lefty, it has been great up until this point. Have any of you experienced swingarm failure on any brand of bike before?

I've broken 2 Jamis Dakar's... First one was an XLT 1.0 both chainstays completely snapped away from the drop outs (bike broke in half)... see below:

And the second was a Dakar XC comp and I broke the non-drive side chainstay at the drop out. Again, see below:

Both times Jamis sent me a new swing arm (which oddly enough had reinforced gussets where the old frame broke). Lots of times bike companies have life time warranty on their frames BUT the swing arm in some cases is not considered part of the frame... sometimes...

Is O&B's gunna warranty that for you? Good luck man!

I broke a swingarm on a Rocky Mountain once - not after three months though. As a mechanical engineer, I can say that sometimes stuff breaks (most everything will sooner or later), and sometimes defects happen. Hopefully you have an isolated incident.

I will resist "Crack-n-Fail" comments regarding Cannondales!

Yeah, they are going to warranty it, they said it was a clean snap and not a result of damage. They are speculating there was not enough weld bead on the joint, or too much was ground off. Nice pics of the busted Jamis, mine broke at the opposite end--right near the crank. I see the Jamis also broke on a weld. On the Rize there are no welds where the swingarm meets the dropout, just at the opposite end. I don't understand why they used any welds at all, since this is the only spot on the whole bike that is welded.

Unfortunately it will be at least two weeks, they have to manufacture another swingarm assy (fortunately still made in Pennsylvania snd not china yet), but this tells me it doesn't fail too often if they don't have any spares.

They are going to inspect the bike for any other possible resultant damage and replace if necessary.

I'm lovin' those new Specialized magnesium pedals, though. [/img]

slow to jump in on this topic but can I can add to the carnage. Broken non drive side chain stay. speicalized enduro.

Months of hard riding later, the replacement swingarm is holding up just fine, as is the rest of the bike!