Hi team,
Just to follow up on this post i originally put up with my 2017 850.
Following this post, I did get my alignment corrected, and it delivered no improvement to my belt life. I think it actually got worse. I ended up trading my 2017 in for a 2018 850 which obviously had the My2018 belt life upgrades. This delivered some improvement to belt life, but it was still totally disappointing.
I would say the My2018 updates took me from 100km per belt to 200 km per belt.
On the 2018 sled my alignment was spot on. I can confidently say that this is not the global issue with this sled, although it may be a compounding issue on some sleds. I spent considerable time playing with different clutch calibrations to see if we could refine shift consistency to stabilize peak rpm, minimize over rev, and improve back shift. I would say this process got me closer to 300 km per belt.
My opinion after running hard at belt issues on 2 years of these selds, is that the fundamental issue is excessive engine movement / vibration due to the long stroke 850. BRP is trying hard to counter act this with their "wobble clutch", and continually stiffening motor mounts in each years Belt life updates.
unfortunately, upon watching the unveiling of the MY2019 belt life upgrades, I've had to move on to a mountain cat as BRP has only confirmed to me that there is no way to correct the vibration in the 850 power plant...only band aids to put over top of it.
As can be seen in the 2019 updates, BRP is again stiffening motor mounts, however it clearly doesn't solve the base issue of excessive motor vibration. This which is confirmed by the fact that their second update is a fan clutch and radical air movement technology to run past the clutches to deal with what they know is excessive heat being generated by the engine vibration. The 3rd update of the belt guard is nothing more than a distraction, which is confirmed by them in their roll out and not even an issue.
At the end of the day, if you ride the 2019 850 hard in the mountains, i would predict 200-400 km per belt. The regular rider may be able to get around 1000km. The disappointing part here is that on the xm, these riders now getting 1000km, used to get 3000 - 4000 km per belt. BRP will isolate the hard riders and rider blame, and eventually you will be on your own with an under performing machine, paying for belts, and dealing with the compounding wear and tear of a constantly overheated and shock loaded crank.
Currently have 750 km on my mountain cat, and have not had a single belt issue.
Good luck boys.