SR SUNTOUR GENERAL SUSPENSION FORK MANUAL

Overview

The SR SUNTOUR suspension fork is a complex mechanical system. This manual provides essential information for its correct installation, use, and maintenance. Always refer to this manual for guidance.

Important Safety Information

WARNING! Failure to follow all warnings and safety instructions can cause product malfunction, resulting in an accident, severe personal injuries, or even death to the rider.

• Read this manual thoroughly before using your suspension system.
• These instructions contain important information about the correct installation, service, and maintenance of your suspension fork. Common mechanical knowledge may not be sufficient.
• Your suspension fork should only be installed, serviced, and/or maintained by a trained and qualified bicycle mechanic with specialized tools.
• SR SUNTOUR suspension systems contain fluids and gases under extreme pressure. Never attempt to open any SR SUNTOUR suspension system, as parts can be violently ejected.
• SR SUNTOUR suspension forks are designed as a single integrated system. To avoid product malfunction and accidents, use only genuine SR SUNTOUR spare parts. Using third-party supplier spare parts also voids the warranty.
• Your suspension fork is not intended for jumps, aggressive downhill rides, freeride, or dirt jumping if the warning sticker on your suspension system prohibits these activities. Disregarding these instructions may cause your suspension fork to fail, resulting in an accident, personal injury or death, and will void the warranty.
• SR SUNTOUR suspension forks are designed for use by a single rider.
• Select the correct suspension fork according to your frame's dimensions and your personal riding style. Installing a suspension fork that does not match your frame's geometry could result in failure of the suspension fork or frame itself, and will void the shock's warranty.
• Know the limits of your skill and experience, and never ride beyond them.
• Read, understand, and follow all owner's manuals provided with your bike and all of its components.
• Always be equipped with proper safety gear, including a properly fitted and fastened helmet. Use additional safety protection according to your riding style. Ensure your equipment is in flawless condition.
• Even if you have used a suspension system before, ride carefully and slowly to become accustomed to the feel of your new suspension fork.
• SR SUNTOUR suspension forks are not equipped with front reflectors for use on public roads. If you intend to use your bicycle on public roads or bicycle paths, you must install the required front reflectors. Please contact your dealer.
• If using a bicycle rack that requires the front wheel to be removed, carefully insert and remove the dropouts from the bike rack. Do not bend the dropouts.
• If using a bicycle rack that fastens the bicycle at the front dropouts only, then the rear wheel must be securely fastened to prevent movement. Movement of the rear wheel can damage the front dropouts, and this damage may not be visible.
• If the bicycle has fallen off the bicycle rack, have it inspected by a qualified bicycle mechanic before riding it again.

Before Every Ride

WARNING! Avoid serious personal injury or even death. Do not ride the bicycle if any of the following criteria are not met! Correct any condition before you ride.

• Inspect your bicycle and suspension system, including handlebars, pedals, crank arms, seat post, saddle, etc., for any cracks, dents, bent, or tarnished parts. Also, check for any oil leaking from your shocks. Be sure to check hidden areas on the underside of your bike. If any condition exists, consult a trained and qualified bicycle mechanic to determine the cause and make any necessary corrections.
• Compress your suspension system with your body weight. If it feels too soft, make the necessary adjustments until you have reached the correct SAG value. Refer to the SAG section in this manual.
• Ensure your brakes are properly installed/adjusted and work correctly.
• Spin the wheels. Make sure that wheels are perfectly centered and do not contact the suspension fork or brakes.
• If using a quick release system, ensure all levers and nuts are properly tightened. If using a through axle system, ensure all fixing bolts are tightened with the appropriate torque values, strictly following the manufacturer's instructions.
• Check the cable length and routing of your components to ensure they do not interfere with the bicycle's steering.
• If using reflectors for on-road cycling, ensure they are clean and properly installed.
• Check mounting hardware of all components to ensure everything is tightened.
• Bounce your bike on the ground while looking and listening for anything that might be loose.

Fork Assembly

WARNING! Avoid product malfunction, an accident, personal injury, or death. Your new SR SUNTOUR suspension fork should be installed, maintained, and serviced by a qualified and trained bicycle mechanic. Avoid product failure and an accident, personal injury, or death. All mounting screws must be tightened with the respective torques specified by the manufacturer of each individual component (i.e., brake, headset, etc.).

1. Remove the old fork from your bicycle. Remove the headset crown race from the fork.
2. Measure the length of the steerer tube of your old fork and compare it to the length of the steerer tube of the SR SUNTOUR fork. The standard length of SR SUNTOUR suspension fork steerer tubes is 255mm. It may be necessary to shorten the steerer tube to the correct length.
3. Install the fork crown race firmly at the top of your fork crown. Reattach the fork assembly (headset, spacers, handlebar stem) to the bicycle. Adjust the headset until no more play is observed. Further information can be found in the installation instructions of the headset manufacturer.
4. Use the following formula to determine the proper length of the steerer tube: Head tube of the frame + Headset height + Spacer (if applicable) + Height of the stem - 3 mm distance = Length of the steerer tube.
5. Install and properly adjust the brakes according to the brake manufacturer's instructions. If using a disc brake, install the brake only into the designated threaded receptacle hole for the disc brake. Use only cantilever brakes made for use without a reinforcing brace. Follow the assembly instructions of your brake manufacturer. Select the proper length for the brake cable so that it does not interfere with the fork or steering.
6. Reattach the front wheel. Ensure all clamping levers and nuts are set and tightened properly (at least four threads must engage in the adjusting nut when the quick release is locked). If the fork is equipped with a thru-axle system, then all screws must be checked for proper torque. Follow the instructions of the Quick Release or Turn-Axle manufacturer.

Tire Clearance Test

1. Depressurize the fork (if equipped with air suspension).
2. Compress the fork all the way.
3. Measure the distance between the top of your tire and the underside of the fork crown. The distance must not be less than 10 mm! If the tire is too big, it will touch the underside of the crown when the fork is fully compressed.
4. Relieve the fork and pump it up again if it is an air fork.
5. Take into account that the gap is reduced if you are using a fender. Repeat the “tire clearance test” to ensure that the distance is sufficient. You must repeat this test every time you change your tires to another size.

Tire Clearance

WARNING! Using a tire that is larger than the maximum tire size allowed for your fork is very dangerous and can cause accidents, serious injuries, and even death. Inadequate tire clearance will result in sudden and unexpected loss of bicycle control, an accident, personal injury, or death.

Below dimensions are based on the bottom case type. Some numbers are referred based on the bottom case type which have fender mount interface, and some are without. Please check in advance whether the wheel and fork are compatible. The necessary information can be found on the side of the tire. Every tire has a different external diameter (width and height of the tire). For this reason, check the distance between your tire and the fork to make sure your tire does not touch the fork under any circumstances. Bear in mind that the narrowest part of the fork is at the brake boss level. If you want to remove your wheel, you must release the air from your tire, among other things, in order to fit it through the brake boss level.

Suggested Tire Size

* Note: Some of the above dimensions are referred based on "with fender", and some are without. Please check the specification sheet for more details.

Maximum Brake Rotor Size

15AH2/12AH2 Bolted Thru Axle Assembly

Note: Before installation, make sure to check the o-ring is correctly seated at the thread part.

Assembly

1. Fully insert the axle on the drive-side.
2. Tighten the axle with a 6mm Allen wrench by the suggested tightening torque of 8-10Nm.
3. Check the axle's thread. It must be visible.

Removal

1. Loosen the axle on the drive side with a 6mm Allen wrench.
2. Pull out the axle.

20mm Bolted Thru Axle Assembly

1. Slide in the axle and tighten it with a 6mm Allen wrench by the suggested tightening torque of 10Nm.
2. Tighten the safety clamp with a 4mm Allen wrench by the suggested tightening torque of 7Nm.

20mm Cross Thru Axle Assembly

1. Slide in the axle on the quick-lock side.
2. Tighten the axle with the red lever.
3. It is possible to slide the lever into the axle now.
4. Lock the quick release.
5. Set the tensioning force with a 4mm Allen wrench if needed.
6. The lever should be flush to the bottom case.

Q-LOC Assembly

Assembly

1. Check the segmented flange to be expanded before installation and open the lever completely.
2. Slide in the axle until it "clicks". Make sure the segmented flange is expanded.
3. Set the tension of the nut until the flange is flush with the dropout.
4. Close the lever completely. Check if it's firmly seated. Re-tighten the nut if necessary.

Removal

1. Open the lever completely.
2. Press adjust nut until segmented flange retracts.
3. Open the lever completely. Turn nut clockwise until flange stays latched.
4. Pull out the axle.

Setting "SAG"

To achieve the best performance from your SR SUNTOUR suspension air spring forks, adjust the air pressure to attain your proper sag setting. Sag is the amount your suspension compresses under your weight and riding gear and luggage. Sag range should be set to total fork travel. Make sure to set sag with the compression knob in the OPEN position.

The chart below provides the suggested SAG range and the original air pressure settings for SR SUNTOUR air suspension forks from the factory. Remember that these are starting points. Adjustments will vary based on rider ability, trail conditions, frame design, and personal preference. After setting up your suspension fork, check your sag to ensure you are within the recommended SAG settings.

The SAG is the compression caused by the rider's weight, including equipment (such as backpack), seating position, and frame geometry, not by riding. Every rider has a different weight and seating position, therefore the front fork will sag more or less. To assure proper function of the suspension fork and not interfere with its performance, setting a proper SAG is the important way to find the correct air pressure for your suspension fork.

Setting tip for EQ air forks

1. Put the suggested air pressure and compress the fork at least 50% of full travel several times to equalize the air pressure between positive and negative air chambers.
2. Sit on the bike with equipment (such as backpack) and ask someone to hold the bike. Stand on the pedals, and compress the fork several times. Then sit on your bike in your normal riding position.
3. Slide the SAG indicator O-ring down to the top of the dust seal.
4. Gently step off the bike without compressing the fork further.
5. Check the O-ring position to see if the SAG setting is properly done.
6. If the SAG setting is not properly done, air pressure must be adjusted.

• To increase the SAG, decrease the air pressure.
• To decrease the SAG, increase the air pressure.

Repeat the above procedure until you can find the correct SAG setting.

Air Pressure Adjust

WARNING! The suggested settings in this manual are designed to be a starting point for your first ride. For more details, consult a qualified and trained bicycle mechanic at your bike shop. As you ride and get used to your fork, adjust the settings as needed.

Suggested air pressure (psi) for EQ air system forks

Suggested air pressure (psi) for Air system forks

Note: Above numbers are reference only. Correct air pressure must be adjusted by individual rider while checking the sag.

Air Volume Adjust

Additional tuning options: Air Volume Adjust Spacers

Changing air volume spacers in some fork models is an easy internal adjustment that allows you to change the amount of mid-stroke and bottom-out resistance. Even if you have set your sag, but are using full travel (bottoming out) too easily, then you could install one or more spacers to increase bottom-out resistance. Even if you have set your sag, but are still not using full travel, then you could remove one or more spacers to decrease bottom-out resistance.

Installation procedure and tuning options are suggested as below chart.

EQ air system forks

Air system forks

Note: Don't exceed the Maximum Volume spacers number because this can damage your fork.

Coil Spring Preload

The fork can be adjusted to the rider's weight and preferred riding style via the spring preload. It is not the coil spring hardness that is set, but the spring preload. This reduces the "SAG" of the fork when the rider sits down. A medium hardness spring is used as a standard setting. Turn the preload adjust knob clockwise to increase the spring preload and turn it counter-clockwise to reduce it. Two additional spring hardnesses are available for SR SUNTOUR suspension forks - softer and harder than the standard coil spring.

Maintenance of the Fork

As long as moving parts are exposed to moisture and contamination, the performance of your suspension system might be reduced after several rides. To maintain high performance, safety, and long life of your suspension system, periodic maintenance is required.

A suspension system which has not been serviced in accordance with the maintenance instructions will not be covered under warranty.

• Never use a pressure washer or any water under pressure to clean your suspension fork, as water may enter the fork at the dust seal level. Never use aggressive cleaners. We recommend clear water and a damp cloth to wipe down your fork.
• Your suspension fork should be serviced more frequently if you ride in extreme weather (winter time, or in wet/muddy conditions) and rough terrain conditions.
• If you believe that your suspension system performance has changed or handles differently, immediately contact your local dealer to inspect your fork.
• After every ride: Clean the fork stanchion tubes and dust seals and maintain with an oily cloth. Check stanchion tubes for dents, scratches, or other discoloration or leaking oil.
• Every 50 hours: Maintenance 1 (at dealer).
• Every 100 hours or once a year: Maintenance 2 (at dealer, ideally before winter time in order to protect all parts from the effects of weather by proper greasing).

Maintenance 1:

Check function of fork / check torques of mountings screws and nuts on bottom of lowers (suggested tightening torque: bolt: 10Nm, nut: 8Nm) / check for scratches, dents, cracks, discoloration, signs of wear, and signs of minor corrosion (maintain with oily cloth), or oil leaks.

Maintenance 2:

Maintenance 1 + disassembly / cleaning the entire fork inside and out / cleaning and lubricating dust seals and slider sleeves / checking torques / adjusting to the rider's liking. Before disassembly, check the slider sleeve play of the fork. To do so, apply the front wheel brake and gently push the bicycle back and forth at the handlebar stem shaft. Replace the slider sleeves if the play is excessive (more than 1 mm at the fork brace).

Intended Use

This table outlines the intended use for various SR SUNTOUR fork models across different cycling disciplines and e-bike classifications.

Note: Some of above dimensions are referred based on "with fender", and some are without. Please check the specification sheet for more details.

Intended Use

The following table indicates the intended use for various SR SUNTOUR suspension forks across different cycling disciplines and e-bike classifications. '0' indicates that the specific use is not recommended for that fork model.