Hi
I broke the chainstay on my FM036 after 4.5 years. I must state that after doing a MtB skills course two years ago I have definitely become more air born in my riding but nothing dramatic, so for example taking off from ramps over small fallen trees and getting air from the local pump track humps, so really only things of around a two foot height.
Three weeks ago I found a small square concrete platform next to a local play area which measured about 10ft x 10ft and 2ft high. I decided to practice repeated roll offs and jumps,'starting low to high as there was a ramp to the top which made this possible.
After spending half hour practicing I noticed after a jump landing some flex in the rear but I thought I had broke the wheel bearings and decided to go home. On closer inspection I had broken the chainstay on the right side all the way round clean through and the left seemed to be cracked only on the outer layer of carbon.
Well a new stay is $160 plus shipping but I decided to get a carbon repair kit as I've repaired my road bike ok some 9 years ago.
I've now repaired the chainstay ok and basically wrapped cracks on both sides with four layers of carbon and hope this is stronger than before.
The reason i think the chainstay broke is that the landing was not as straight on whilst trying to avoid obstacles after landing and maybe this stressed the one side too much OR I may have simply tested the limit of this xc frame.
Either way I've not changed the way I use the frame and its holding up well!!!