Manitou SIX - User Manual

This document is a user and service manual for the 2003 Manitou SIX suspension fork, a component designed for bicycles. The manual provides comprehensive instructions for installation, usage, and maintenance, aiming to ensure safe operation and longevity of the fork.

Function Description

The Manitou SIX suspension fork is a critical component of a bicycle's front suspension system. Its primary function is to absorb shocks and vibrations from the terrain, providing a smoother and more controlled ride. This absorption helps to maintain tire contact with the ground, improve steering precision, and reduce rider fatigue, especially during off-road cycling. The fork utilizes a combination of coil and MCU (Microcellular Urethane) springs to achieve its suspension characteristics. It is designed for off-road use and is available in configurations suitable for both V-brakes and disc brakes. The fork's design includes a 1 1/8-inch threadless steerer tube and an RA casting, which contributes to its structural integrity and performance. The suspension travel can be adjusted, allowing riders to fine-tune the fork's response to different riding styles and terrain conditions.

Usage Features

The Manitou SIX fork is delivered fully assembled and ready for installation. Before use, it is crucial to properly install the fork onto the bicycle, which may involve cutting the steerer tube to the correct length to fit the bicycle's head tube. The manual strongly advises that if a user is unfamiliar with this procedure or lacks the necessary tools, a qualified bicycle mechanic should perform the installation. A key safety feature highlighted is the requirement for a handlebar-mounted reflector for on-road use, as the fork itself does not come with reflectors suitable for public roads.

The fork is designed to "break-in" during the first few rides, typically around 20 hours of total riding time. During this initial period, the fork may feel slightly stiff or "notchy," but it will gradually become smoother and more responsive as the internal components settle. After the break-in period, riders are encouraged to recheck and fine-tune rebound and preload adjustments to optimize the fork's performance for their specific riding style and weight. The manual emphasizes the importance of regular inspection before each ride, checking for any signs of damage, bending, cracking, creaking, or leaks. If any such issues are found, the fork should not be ridden, and professional inspection or replacement parts should be sought.

The fork's travel can be converted between 80 mm and 100 mm, allowing riders to adapt the suspension to different preferences or terrain. This adjustment involves removing the lower legs and repositioning an internal clip. Additionally, the fork's spring rate can be customized by changing the coil springs and/or MCUs. The manual provides a sag measurement guide and a recommended spring chart based on rider weight, enabling users to select the appropriate spring kit for their individual needs. Adjusting the spring involves removing the preload adjuster knob and replacing the spring stack, ensuring proper lubrication during reassembly.

Maintenance Features

Regular maintenance is crucial for the performance, safety, and longevity of the Manitou SIX fork. The manual outlines a detailed service schedule based on riding conditions and frequency. A key maintenance feature is the Microlube system, which allows for easy lubrication of the fork. Riders can inject Manitou Prep M lubricant into the grease ports located on the back of the fork legs using a Microlube lubricant gun. This process helps to keep the internal bushings lubricated, reducing stiction and ensuring smooth operation. The manual advises injecting grease until stiction is eliminated, but cautions against overfilling, which could force grease past the upper bushing and dust seal.

The use of fork boots is explicitly stated as a requirement for maintaining performance and warranty validity. Operating the fork without boots will shorten its life, decrease maintenance intervals, and void the warranty. Before every ride, users should wipe the inner legs clean, check quick release skewers for proper adjustment and tightness, inspect the headset, and verify brake adjustment.

For more in-depth maintenance, the manual describes procedures for fork disassembly, cleaning, and inspection. This includes removing the lower legs from the crown/steerer assembly, wiping clean the inside of the fork casting, stanchion tubes, fork boots, and crown. During disassembly, all parts should be inspected for excessive wear or damage, particularly the stanchions, bushings in the outer legs, and the spring stack. Any worn or damaged parts should be replaced. The manual provides specific instructions for removing bolts and separating components, ensuring that the process is followed correctly to avoid damage.

The service schedule differentiates between "Normal Conditions" (short/infrequent rides, long/frequent rides) and "Severe Conditions" (mud, rain, snow, extreme dust – short/infrequent rides, long/frequent rides), with varying frequencies for lubrication and full disassembly/cleaning. For instance, under normal conditions with short/infrequent rides, the fork should be disassembled, cleaned, and lubricated every 4-5 months, with spring stack lubrication as needed. Under severe conditions with long/frequent rides, this interval shortens to every 4-6 weeks.

The manual also includes critical safety information regarding the fork's construction. It explicitly states that the steerer tube and stanchions (inner legs) are a one-time precision press fit at the factory and cannot be removed from the crown. Any attempt to remove or replace these components will permanently damage the crown, render the fork unsafe, and void the warranty. Similarly, threading a threadless steerer tube is prohibited as it weakens the tube and creates an unsafe condition. Any alterations or modifications to the fork beyond those described in the manual are considered unsafe and should not be attempted without consulting Answer Customer Service.

Answer Products recommends that aggressive off-road riders or those who ride frequently over rough terrain return their suspension fork every two years for a thorough inspection and update by a Manitou authorized dealer. This ensures that the fork remains in optimal condition and addresses any potential wear or issues that may not be apparent during routine user inspections.