Who has replaced the stock rear shock on their 2015 viper stx

[Akitaone1]

I have read that stock fox float 3 rear shock is not very good for trail riding. I agree and want to replace it. Has anyone put a certain shock in and would recommend it.

 

[Joseph Levandoski]

I had a 2014 SR Viper XTX (same rear suspension as your STX) and replaced multiple Float 2s under warranty before switching to the simple coil shock out of a 2015 SR Viper MTX (fair warning, this coil shock has coil preload-only adjustability). Another option is to replicate the 2019 SideWinder XTX models and install a QS3 (which I enjoy very much, but will be more expensive due to the adjustability and performance upgrade). I've outlined the part numbers and price for each as below.

2015 SR Viper MTX setup (rear arm): shock (8KG-G7480-00-00; $212.99), spring guide (8JP-F2214-00-00; $5.99), spring (8KG-G7489-00-00; $77.99)
2019 SideWinder XTX setup (rear arm): shock (8MF-G7480-00-00; $499.99), spring (8MF-G7489-00-00; $71.99)

Something to note, I didn't include the part numbers of the hardware needed (only the shock and coil spring) as your current hardware can be reused (unless it's trashed).

 

[Wannaviper]

I replaced my XTX rear shock and center shocks with QS3's, and it made a huge difference in the ride. I think that in 2019 all, or at least the XTX LE's changed over to the QS3's, and now with the new 146" skid, all the Sidewinders XTX'S are QS3. I think Yamaha finally figured out that the Float's just did not deliver the ride quality that riders wanted.

 

[Joel Boucher]

It is sad how long it took them to give up on the air shocks. Had a buddy with an 06ish FireCat with those and it was awful compared to Standard Cat . Everybody hated them you would think by 2010 they would have been gone

 

[Joseph Levandoski]

It is sad how long it took them to give up on the air shocks. Had a buddy with an 06ish FireCat with those and it was awful compared to Standard Cat . Everybody hated them you would think by 2010 they would have been gone

I'm not sure it's really any different than the mountain bike industry (which Fox shares a ton of it's technology with). Only a few years ago, mountain bikes came exclusively with air shocks because they were lightweight - a common push shared between both industries. Now it's all about ride and handling (both in bikes and snowmobiles) - most manufacturers are now switching out to coil because of the greater compliance those types of shocks provide. I figure Fox had a lot of say in the design (valving, weight, and other specs) of the mountain-derived rear suspension found in the pre-2020 141"+ models.

 

[Wannaviper]

The Float Evols are probably a pretty decent shock; I kept my front Float 3's and added Hygear's Dual Pressure chamber, and they actually work very well and provide good front end performance. Having the ability to separately adjust ride height and bottoming is nice. I still think that the QS3's are a better shock, and the ease of adjusting them to conditions is a great feature. If AC and Yamaha had done the Evols all around instead of the single chamber Floats, I suspect that people would have been much happier with their shocks.