Rear Shock Spring
The Hyperpro Progressive Rear Spring enhances cornering, reduces braking distance, and improves overall bike balance and feedback, fitting onto the original shock for easy installation.
NOTE
Rear Shock Spring
Japanese model
FITMENT
1995 - 2019 YAMAHA TRX 850
SKU
SP-YA08-SSB004
Let customers speak for us
The YSS shocks are a huge improvement over the stock 2015 Triumph Scrambler 900 rear shocks. The quality is similar to the O shocks I am running on my 1999 Harley Road King. Thanks
My customers are very happy with their Nivomat purchases. One guy picked up his friend's bike for him and called me to order for him after riding his buddy's bike.
Happy withe your service.
Guys were easy to work with to get me the right option. Actually talked me down to a less expensive suspension because I ride on roads not race tracks.
The system is great, a significant noticeably difference. Great customer service too!
I purchased RZ362-350TRL-48-88 for my Triumph Street Cup. and so far, so good. Nice to actually get feedback from my rear shocks as the stock shocks were DOA. Now I need to dial them in a bit, and it should be even better than the base setting.
I spent an excessive amount of time watching YouTube videos full of excellent reviews of this suspension, but was still hesitant to try it. The reviews were just too good. They had to be embellishing some. I’m here to tell you they are not. If anything, they may be under-selling it. The wildest part to me - it really does self-adjust when you add a passenger. I feel very foolish for having waited so long to upgrade. Don’t be like me. If you have the funds, this should be your first upgrade. By far, the most increase in enjoyment of the ride of any of the modifications I’ve made to bikes over the years.
I purposely waited to complete a review on my Wilbers Nivomat system so I could have more time to ride and critique it. I've still only ridden about 1,000 miles on it so far, but it is far superior to the stock suspension. I have not ridden a bike with the Legends suspension which is supposed to be the Nivomats competition, so I can't make that comparison. The Nivomat is a perfect blend of sport and touring. It gives you confidence cornering with positive feedback and no mush. I routinely bottomed out the stock suspension, but not the Nivomat. It holds firm and has improved my ride quality. It has been a wise purchase and well worth the money. Although I must say I'm glad I made my purchase before the tariffs.
Had the front & rear stock suspension replaced by EPM Performance on my 2021 HD RG Ltd in June2025 @~30,600 miles.
Immediately felt huge difference going over bumps on short-local rides.
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Knew the true test was to wait and write a more realistic review AFTER my 9k mile 23 day trip coast to coast from PA to CA; which was some highway and lots of mountains and backroads and conditions and twisties.
Yes love these and would recommend set purchase for any touring bike.
PRO's: Smoother ride; excellent handlings & cornering; bike feels like it grabs/sticks to the road surface.
CON: This is just my assessment based on the ride/feel; front end is "stiff".
Mike and his team were easy to work with; I will be a repeat customer; to the tune of I recently purchased a slightly used 24 rg ltd that already had Legends front & rear and considering changing to Wilbers set as on the first bike.
Called EPM for verification that my information I provided them was correct. They answered my questions and shipped promptly.
The preset sag was spot on and installation was easy. Installed new fork kit. Ride is great. The more I ride it the more I realize how good the Wilbers Nivomat system is.