I don't have experience with mullet'ing the Smash (either with stock stays or MT stays), but I did play around with it on my Sentinel last year. You can read my thoughts here: https://forums.mtbr.com/transition-bikes/sentinel-mullet-experiment-1110227.html
Now, keep in mind:
1) the Sentinel v1 leverage curve sucks balls to begin with, and mullet'ing it made it worse. It is regressive to sag then slightly progressive. The anti-squat is not very effective. Shifting weight bias further rear by slacking it out 1 degree makes this worse.
2) I tried this for only 1 ride, and it was with my buddy's worn out DHR that wouldn't hold air. I didn't give it a fair shake because of how bad the bike pedaled. I also didn't have a spare spring to throw on my shock to help pedaling, nor did I fiddle with the LSC.
3) The 333 BB height felt low as fuck. My current 349 BB feels a smidge high. I'd love to try a mullet with a BB around 340.
4) That said, it did feel like the rear end wanted to pivot around faster in tight corners, and accelerated better. I don't know how much of the cornering came from the wheel size, and how much from the super low BB.
I've looked at various MegaSmash setups and passed due to the BB height, and ordered a set of Gnarvana stays instead, which I'll run short forked. But I'd love to see a dedicated set of mullet stays, designed around 160 29er fork: 150 / 160 travel, 64.5 / 64 HTA, 76.5 / 76 STA, 345 / 340 BB height, and ~340+/- chainstay length. I'd buy that immediately.
Now, keep in mind:
1) the Sentinel v1 leverage curve sucks balls to begin with, and mullet'ing it made it worse. It is regressive to sag then slightly progressive. The anti-squat is not very effective. Shifting weight bias further rear by slacking it out 1 degree makes this worse.
2) I tried this for only 1 ride, and it was with my buddy's worn out DHR that wouldn't hold air. I didn't give it a fair shake because of how bad the bike pedaled. I also didn't have a spare spring to throw on my shock to help pedaling, nor did I fiddle with the LSC.
3) The 333 BB height felt low as fuck. My current 349 BB feels a smidge high. I'd love to try a mullet with a BB around 340.
4) That said, it did feel like the rear end wanted to pivot around faster in tight corners, and accelerated better. I don't know how much of the cornering came from the wheel size, and how much from the super low BB.
I've looked at various MegaSmash setups and passed due to the BB height, and ordered a set of Gnarvana stays instead, which I'll run short forked. But I'd love to see a dedicated set of mullet stays, designed around 160 29er fork: 150 / 160 travel, 64.5 / 64 HTA, 76.5 / 76 STA, 345 / 340 BB height, and ~340+/- chainstay length. I'd buy that immediately.