I have had a 2016 Stache 7 for 14 months now.
I have found the Chupacabras to be terrible in wet, deep mud.
Absolutely no grip whatsoever, laterally or when pedalling.
I have had to get off and push the bike along muddy bridleways because trying to pedal just spins the rear wheel so badly that the back slides sideways, and I end up facing 90 degrees to my direction of travel.
My riding mates find it hilarious of course!
There is no lateral grip either, the bike slides sideways down-hill on off-camber trails, leaving me stuck in the bottom of a rain gully, instead of riding down the descent up high on the side of the gully, like I do on my other bikes.
The next problem is rock-strikes that split the sidewall constantly.
Running the rear tyre at 12-14 PSI (I am 11.5 stone), gives me good grip for climbing, but that isn’t enough air to stop the rim hiting rocks on descents, that pinch the sidewall and split the tyre.
I have ruined many rides where the sealant won’t seal a split near the bead of the tyre, and I have had to limp home and tell the other guys to carry on without me.
I have had many occasions where a sidewall split has sealed, but I am covered in sealant and so is the bike, and I have lost half the air in the tyre before it has sealed.
I replaced the rear Chupacabra with a Surly Dirt Wizard which is loads better in the mud, and seems to be better for sidewall strength as well.
But Trek have sacrificed tyre strength/longevity for light weight, which makes the Chupacabras not up to the job.
Pumping the tyres up harder to try and stop the rim-strikes, removes the advantage of low tyre pressures with regards to grip and control, and makes the bike bounce off everything and become really hard to control.
The marketing videos you see for plus bikes are cheating in my opinion with the tyre pressures. They show really low tyre pressures on the climbs, showing huge traction and grip. You can see the sidewalls wrinkling as the bike rolls over the rocks/roots.
But in the same video when they then ‘hoon’ down the descent, boosting off everything – see how much air they have in their tyres then!
They have stopped at the top of the climb and pumped the tyres up.
I stopped riding my Stache because of the problems I had with it, and went back to my FS bike.
I have now bought standard 29er wheels for it (Boost of course ££££) and I will use it as a winter bike with standard 29er wheels/tyres, and take advantage of the mud clearance.
I am annoyed that the shop I bought it from wouldn’t let me test ride one first, not even just up and down the street outside, but that is an issue for a different forum post!