The FEP432 spring is a precision spare part designed by SR SUNTOUR to ensure proper operation of the patented Q-Loc2 system on Ø15mm thru-axles. This spring plays a critical role in the expansion mechanism that guarantees safe and quick locking of the front wheel, with the characteristic "click" confirming proper engagement of the axle.

The heart of the Q-Loc2 system

SR SUNTOUR's Q-Loc2 system represents a major evolution in quick-release thru-axles. The FEP432 spring is the mechanical element that allows the patented expansion system to function perfectly: it ensures the retraction and expansion of the locking wings during insertion and removal of the axle. Without this spring in perfect condition, the mechanism loses its ability to firmly hold the wheel, compromising the safety and rigidity of the assembly.

Universal Q-Loc2 Ø15mm compatibility

• Standards covered: Compatible with all Q-Loc2 axles with 15mm diameter, whether standard 15x100mm or Boost 15x110mm
• Axle range covered: Works on models 15QLC2 (chromoly), 15QLC32 (aluminum for NCX/NRX), 15QLC2Ti (titanium lightweight version), as well as their 110mm Boost variants
• Applications: All SR SUNTOUR forks equipped with the Q-Loc2 15mm system: XCR, Raidon, AXON, AURON, Durolux, NRX, NCX and NEX ranges
• Interchangeability: Standardized part across the entire Q-Loc2 15mm platform since its introduction

Maintenance and replacement

The FEP432 spring is a wear part that may require replacement after intensive use or in case of loss during complete disassembly of the axle. Symptoms of a failing spring include lack of tension in the mechanism, difficulty engaging the axle correctly, or absence of the characteristic locking "click". SR SUNTOUR recommends checking the spring's condition during each major fork service.

Installation and maintenance

• Simple assembly: The spring is inserted into the axle body during reassembly of the Q-Loc2 mechanism, following the SR SUNTOUR technical manual instructions
• Tools: Manual installation, no special tools required for spring positioning
• Complementary kit: For a complete overhaul, the FEP432 spring can be combined with the SSFQLOC kit which includes circlips, washers and O-rings
• Associated parts: Compatible with steel wings (SSFQLOCAC) or aluminum wings (SSFQLOCAL), FSW093-10 washers and FSS038 snap rings

Essential technical points

• Mechanical reliability: High-quality steel spring designed to withstand thousands of opening/closing cycles
• Dimensional precision: Strict tolerance to guarantee proper functioning of the patented expansion mechanism
• Economical packaging: Sold individually to allow targeted replacement without having to purchase a complete axle
• Availability: Official SR SUNTOUR spare part, referenced in after-sales service catalogs

Why choose the original part

Using the original FEP432 spring guarantees maintenance of Q-Loc2 system performance and safety. The dimensions, return force and durability are specifically calibrated to work in harmony with the other axle components. An unapproved substitute spring could compromise proper axle engagement and present a safety risk for the rider.