Buttercup Rear Shocks (KSI)

Performance suspension at a cost-effective price — still 100% handmade in the USA. The Killer Shox Buttercup (KSI) uses a patent-pending internal Rezy system to deliver maximum control without the price tag of a full piggyback setup. Built specifically for your bike and your weight. No imported parts, manufacturer-direct.

Why the KSI?

• Internal reservoir system — high comfort with minimal performance sacrifice
• Patent-pending design tuned to your individual rider profile
• USA-machined with American-sourced metal, built in-house
• Buttercup valving technology for unsurpassed ride quality
• Manufacturer-direct — no middleman markup

Installation Notes

Longer-than-stock shocks may require modification — check your bike. We recommend 13-1/2" for most applications, though you're free to choose (parts are available if you later want to change length).

• Touring 2013–2017: 14-1/2" or longer shocks cause the swingarm to hit the transmission.
• Other Touring models: swingarm usually contacts the transmission at shocks over 15-1/2".
• All Nightsters: over 15" causes swingarm-to-gas-tank contact; over 14" and the stock exhaust hits the shock bolt.
• Dyna models: shocks longer than 13-1/2" allow the chain to drag on the case.