YSS MZ456 Review

[Nucking Foob]

I bought the YSS MZ456 shock for $400 USD. Box includes the shock, preload spanner, and paperwork.

Adjustability:

Length adjustment  is possible by loosening the jam nut and threading the clevis in or out. The shock was already set to the same eye-to-eye length as the OEM shock. The preload collar is fully accessible from the side of the bike and can be adjusted with the supplied tools. The rebound adjustment is easily accessible and adjustable by hand. Rebound has a total of 33 clicks, and out of the box it was set to 14 clicks out.

Installation:

Park bike on kickstand. Remove chain guard. Remove left heel guard. Loosen both front and rear shock nuts. Lift up the bike by positioning a jack under the right side foot rest bracket. Remove the rear shock bolt then the front bolt. Remove the OEM shock. Position the new shock's eyes with the bolt holes and insert the front and rear shock bolts  slightly holding up the rear wheel to align the shock eye with the bolt hole. Thread on the front and rear nuts. Lower the bike from the jack. Torque front shock nut to 33 lbft (45Nm) and the rear nut to 30 lbft (41Nm). Reinstall the chain guard and the ankle guard plate. 

Results:

I've tried various adjustments to the preload and damping clicker, but I can't find a setting that reduces harshness and improves bump absorption. The stock shock on the 2018+ MT-07 feels more comfortable and absorbs bumps better in my opinion. As a rider weighing 175 lbs with gear, mainly commuting on rough city streets, the $400 YSS shock upgrade hasn't significantly improved my experience. While it might greatly benefit pre-2018 MT-07 models known for soft rear suspension, for the 2018+ models with adjustable OEM shocks, the YSS upgrade offers only slight improvement.

Edited August 17, 2023 by Nucking Foob

[Nucking Foob]

[Nucking Foob]

I believe the faults of the YSS shock are twofold:

1) No selection of spring rates when purchasing the shock. There is no such thing as a one-size-fits-all spring rate in my opinion. I may have received an inappropriate spring rate for my weight and riding style. 

2) This shock is a gas-emulsion type, as I heard liquid sloshing when I unboxed it. Gas-emulsion shocks must be mounted vertically, but the MT07, by its own design, has the shock mounted horizontally. This results in poor damping performance. 
 

Edited March 28 by Nucking Foob