Owners Manual Öhlins Superbike Front Fork FG 670
Safety signals Important information concerning safety is distinguished in this manual by the following notations: ! This Safety alert symbol means: Caution! Your safety is involved. WARNING! Failure to follow warning instructions could result in severe or fatal injury to anyone working with, inspecting or using the suspension, or to bystanders. ! CAUTION! Caution indicates that special precautions must be taken to avoid damage to the suspension.
Öhlins Front Fork FG 670 This Super Bike front fork is an improved version of FG 570 with pressurised damping system. FG 670 is based on 6 years experience from factory road racing. The pressurised damping system improves the front fork function at high frequency movements. The immediate damping responses improve the tyre feeling and also give more possibilities for adjustments.
Adjusters Your Öhlins super bike front fork is provided with the following external adjusters: • • • Spring pre-load adjuster Rebound damping adjuster. Two type of compression damping adjuster: - Reservoir valve adjuster in the lower part of the fork leg. - Main valve bleed circuit. NOTE! The rebound damping adjuster is located at the top of the right hand fork leg. The Main valve bleed circuit (compression adjuster) is located at the top of the left hand fork leg.
Setting up your forks F1 F2 R1 R2 A-D. Bike on a stand R3 E. Bike on the ground Here are some basic guidelines, how to set up your Öhlins front forks. However, you must remember that the front forks are just one part of your motorcycle and to get it to work properly, the whole motorcycle has to be set up according to your bikes manual. 1 Put your bike on a front stand and fit the Öhlins front fork. NOTE! The lower triple clamp must not be tightened to more than 12-15 Nm.
Changing springs 1. Unload the spring pre-load completely by turning the adjustment nut counter clockwise as far as possible. Use a 14 mm wrench or socket. 1 2. Loosen the screws that hold the fork legs in the upper triple clamps. 3. Remove the Top nut assembly. Use tool 797-01. 2 14 mm wrench 3 4 Tool 797-01 14 mm wrench 4. Remove the top nut assembly from the piston shaft. Use a 14 mm wrench to the top and a 19 mm wrench to hold the nut on the lower side of the top nut. 5.
Changing seals 1. Remove the fork legs from the motorcycle. Put the fork legs in upright position for about 5 minutes to allow the oil to settle. 2 4 2. Fasten the fork leg in a vice. Use soft jaws. 3. Carry out instructions 1 to 5 in “Changing springs”, page 6. 4. Drain the cylinder tube from oil. 5. Remove the outer tube, clean the seal and check the condition. If the seal is in good condition apply some red grease (146-01) to it. A damaged seal must be replaced! 5 6 180 0 1st, Circlip 6.
Dismantling the Forks 1. Remove the fork legs from the motorcycle. Put the fork legs in upright position for about 5 minutes to allow the oil to settle. 2. Fasten the fork leg in a vice. Use soft jaws. 2 3 3. Unload the spring pre-load completely by turning the adjustment nut counter clockwise as far as possible. Use a 14 mm wrench or socket. NOTE! Do not use the pre-load adjuster to tighten or loosen the top-nut assy. 14 mm wrench 4 5 Tool 797-04 14 mm wrench 4. Loosen the top nut assembly.
! WARNING! Releasing high pressure gas from the front fork can be hazardous. Do not perform any kind of service until gas pressure is completely released. 9 10 Tool 720-03 Tool 720-02 9. Remove the circlip. 10. Use tool 720-03 to lift up the reservoir end cap. Install the tool 720-02 into the gas piston. 11. Use tool 1797-04 and 1765-03 to unscrew the seal head from the cartridge tube. Remove the piston rod unit. Tool 1765-03 11 12. Fasten the piston rod in a vice. Use soft jaws (727-02).
13. Remove the Piston holder. Use a 22 mm wrench. 13 22 mm Wrench 14 Piston holder 14. Remove the Topout spring, the Sleeve, the Spacer and the O-ring. Topout spring Sleeve Spacer O-ring 15. Remove the Seal head. Check the O-ring and the X-ring. Change them if necessary. 16. Remove the needle and change the O-ring if necessary. 15 16 X-ring 17. Drain the cylinder tube from oil. Seal head O-ring O-ring Rebound neendle 18. Remove the gas piston in the reservoir, use tool 720-02. 19.
22. Remove the outer tube, clean the seal and check the condition. If the seal is in good condition apply some red grease (146-01) to it. A damaged seal must be replaced! 22 23 180 0 1st, Circlip 2nd, Seal 23. First remove the circlip, then the seal and finally the washer. 3rd, Washer 24. Heat the tube where the bushings are positioned. Use a heat air gun. 25. Put the outer tube standing up on a soft suface, seal side facing down. Remove the bushings by pushing them out.
Assembly of the forks 1. Use Tool 786-07 to refit the reservoir tube. Tighten to 45 Nm. 1 2. Use Tool 786-05 to refit the inner tube of the fork leg. Tighten to 80 Nm. 3. Put the outer tube standing up on a soft surface, seal side up. Fit the bushings from the seal side of the outer leg. Install first the upper bushing then the lower one. Use installing sleeve (1759-08), guide ring (1758-04) and attachment bar (1757-01) when installing the upper bushing.
438-02, End piece 1658-03, End piece 1672-01, Collar 1669-01, Sleeve 1693-01, Spring 530-22, Shims 338-11, O-ring 1670-01, Piston Shim stack Comp. 1674-01, Washer Clamp Comp. 1675-01, Nut 4803-11 (3 Nm , loctite 243) Basevalve RIGHT side (rebound leg) 7 7. Apply some front fork oil (1311-01) to the inner tube surface and carefully mount the outer tube (slide it completely down).
10. Grip the piston shaft with soft jaws 727-02. Fit the O-ring on the adjustment needle. Apply plenty of red grease on the O-ring so that the needle slides easily into the piston shaft. 11 10 X-ring O-ring 11. Check the X-ring and O-ring on the seal head. Replace if necessary. Smear plenty of white grease on the X-ring before you fit it. Use tool 0715-01 to get the X-ring into the right position. Tool 0715-01 11 10 Piston holder 10.
NOT CAUTION! The Washers must be positioned correctly (Notice that there is a difference between the compression and the rebound valve). Also make sure to fit the Wave washer (1149-01) in the correct position (convex side facing piston). E! 14 Tool 1765-03 Tool 2810-01 Tool 1797-04 NOTE! The right hand fork leg is the rebound leg. The left hand fork leg is the compression leg. 14. Fit the Seal head tool and the Top-out spring tool on the piston rod.
! WARNING! Use of inflammable gas for pressurising the soch absorber can be hazardous. Use nitrogen gas (N2) only! ! WA R NIN G! 19 20 19. Check the gas pressure stipulated in the spec. card. Dip the needle of the gas tool (1781-01) in red grease and insert the needle through the gas filler valve. 3 Nm Charge with gas to the correct pressure, according to the spec. card. NOTE! Ensure that there is no leakage of gas or fluid. 20. Screw the gas filler screw with O-ring.
Oil level adjustment Compared with conventional type of front forks, the upside down front forks are very sensitive to variations in oil level. Therefore, adjust the oil level with special care. A change in the fork oil level will not affect the spring force at the beginning of the fork travel, but will have a great effect at the end of the travel. When the oil level is raised: The air spring in the later half stage of travel is stronger, and make the front forks more progressive.
Troubleshooting Below are a few examples of how to adjust for the most common road holding problems in Road Racing driving. 4. The front end loses grip coming out of a corner. 1. The front wheel “chatters” entering a corner, the problem goes away, as soon as you let the brakes off, or when you get on the power. • Not enough rebound damping. Put on some more rebound damping. • Too much pre-load. Take off some pre-load. • Rear end is too soft. Put on a harder rear spring. • Front end is too high.
Guidelines The settings on this pressurised Front Fork are based on what currently is being used in Moto GP racing, furthermore the delivery spec is something we like to refer to as a “balanced setting”. This means that the pressure drop over the bottom valves (base valves) and the top pistons (ø25mm) are matched. In order to avoid an unnecessary high internal pressure or risk of cavitation, please use the following guide lines when adjusting the front fork.
Individual adjustments Individual adjustments Below you can find the recommended adjustment range for the top left compression leg adjuster, with different positions on the bottom base valve. From soft to hard: SOFT HARD Base 19 clicks, top 17-20 clicks Base 16 clicks, top 14-18 clicks Base 12 clicks, top 11-14 clicks Base 10 clicks, top 10-12 clicks Base valve: The left bottom base valve can be adjusted from 8- 13 clicks, if top compression is set at 12 clicks open.
Notes 21
Technical information Fork length: 730 mm. Stroke: 130 mm. Free spring length: 260 mm. Rebound adjustment: Base setting 9-12 “clicks”. Maximum open valve 20 “clicks”. Compression adjustment: Base setting 6-16 “clicks”. Maximum open valve 20 “clicks”. Compression adjustment (Base valve): Base setting 6-16 “clicks”. Maximum open valve 20 “clicks”. Spring pre-load adjustment: 0-18 mm (0-18 turns). Spring rate: 4744-95 9.5 N/mm (marking -95). Optional springs supplied: 4744-10 10.
Spare parts list, FG 670 Pos. Part No. Pcs.
Spare parts list, Top nut assey Top nut assy Pos. Part No. Pcs. Description 1 2 3 4 3 5 6 Base valve 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 01473-01 01467-03 00884-04 01474-01 00577-01 03312-01 03309-01 00338-72 03318-05 00338-02 03309-01 03317-01 03309-02 03313-01 03315-01 2 2 4 2 2 2 2 2 2 2 2 6 2 2 2 Type/remarks Circlip Needle Ball Spring O-ring Adjuster Thin Shim O-ring Housing O-ring Thin Shim Wave washer Thick shim Nut Preload socket 16 7 17 Spare parts list, Base valve 18 8 19 Pos.
Spare parts list, Compression valve (LH) Compression valve 1 Rebound valve 2 Pos. Part No. Pcs. Description 1 2 3 4 5 6 7 8 9 10 11 13 01654-09 00530-22 01149-01 00525-18 01447-02 02061-03 01674-01 01675-01 1 1 1 2 1 1 1 1 2 1 Piston holder Shims Wave washer Shims Washer Shim stack (comp.) Piston ring Piston Shim stack (reb.) Washer Washer Nut Type/remarks See spec. card See spec. card See spec. card 3 14 4 Spare parts list, Rebound valve (RH) 5 15 6 7 16 8 17 9 18 Pos. Part No. Pcs.
Service tools Pos. Part No. Pcs.
Notes 27
More info Öhlins Racing AB, Box 722, S-194 27 Upplands Väsby, Sweden Phone +46 8 590 025 00, Fax +46 8 590 025 80 07280-12D, Issued 06 07 26. Öhlins Racing AB, Mattias Johansson, majo/ Update: Tiina Harakka www.ohlins.
