While checking my air filter this morning I noticed a broken spring laying under rear drive shaft.  Seems only one of three remain where the exhaust donut is. Almost 10 hrs of light break in riding so far.  Should I try to find a dealer since we are traveling or just hit up a hardware store?  What could cause the stock springs to snap off? Maybe because they are pretty stiff and possibly stainless which means brittle?

[2015 Z Force 800 53/Trail EPS]

While checking my air filter this morning I noticed a broken spring laying under rear drive shaft.  Seems only one of three remain where the exhaust donut is. Almost 10 hrs of light break in riding so far.  Should I try to find a dealer since we are traveling or just hit up a hardware store?  What could cause the stock springs to snap off? Maybe because they are pretty stiff and possibly stainless which means brittle?

Back pressure on CFMs stretch the connections and/or heat makes the already soft springs go weak..er and fall off. Measure between the two hoops, then deduct 20% of that distance. Then order some Moose exhaust springs and you will never have this issue again.

Thanks for the quick response! I should have searched the forum first.

While checking my air filter this morning I noticed a broken spring laying under rear drive shaft.  Seems only one of three remain where the exhaust donut is. Almost 10 hrs of light break in riding so far.  Should I try to find a dealer since we are traveling or just hit up a hardware store?  What could cause the stock springs to snap off? Maybe because they are pretty stiff and possibly stainless which means brittle?

Back pressure on CFMs stretch the connections and/or heat makes the already soft springs go weak..er and fall off. Measure between the two hoops, then deduct 20% of that distance. Then order some Moose exhaust springs and you will never have this issue again.

I'm looking for some moose springs also as I keep blowing exhaust donuts.  Not quite sure im taking an accurate measurement, but if I am, looks like about 88mm on the exhaust side for my 500zforce.  so that would put me at 71mm, does that sound about right?  New springs from cfmoto for this are at 65mm.  I see Moose has 67mm springs, maybe this will be my best bet?

[2015 Z Force 800 53/Trail EPS]

While checking my air filter this morning I noticed a broken spring laying under rear drive shaft.  Seems only one of three remain where the exhaust donut is. Almost 10 hrs of light break in riding so far.  Should I try to find a dealer since we are traveling or just hit up a hardware store?  What could cause the stock springs to snap off? Maybe because they are pretty stiff and possibly stainless which means brittle?

Back pressure on CFMs stretch the connections and/or heat makes the already soft springs go weak..er and fall off. Measure between the two hoops, then deduct 20% of that distance. Then order some Moose exhaust springs and you will never have this issue again.

I'm looking for some moose springs also as I keep blowing exhaust donuts.  Not quite sure im taking an accurate measurement, but if I am, looks like about 88mm on the exhaust side for my 500zforce.  so that would put me at 71mm, does that sound about right?  New springs from cfmoto for this are at 65mm.  I see Moose has 67mm springs, maybe this will be my best bet?

The "hoops" or loops I refer to are the ones the springs hook to, not the springs themselves. Overstretching any spring will stretch them...and the moose springs will ne much harder to stretch anyway. Just get the right ones...or as close as possible. I don't own a 500 so I can't help you.

A little late, but if anyone is wondering the size....
I bought the 60mm Moose springs and they seem fine.  (2020 500 trail)
"Moose Exhaust Springs 60mm - M7715"
The factory springs are more like a piece of stiff wire than actual spring material...
I had the missing factory springs replaced (warranty) once, and ordered the Moose springs at the same time.   
When I put the Moose springs on, the factory ones were pretty much 'stretched' to their working length, and that's where they stayed, just jingling around loose.
Maybe the dealer way over-extended them when they replaced them....not sure, but they were doing nothing.
So far, the Moose springs are retaining their spring-y-ness and are working as designed.