Solution: Decrease compression “gradually” until control is regained. Again, watch for adverse handling reactions in other riding situations when test riding. Step 5: Adjust the preload. To adjust sag use the preload adjusters, if available, or vary the length of the preload spaces inside the fork. The oil level works most effectively at the end of the fork travel. Preload adjuster (3&4) – Is adjusted by using a C-Spanner or the appropriate wrench/spanner. Furthermore, if you can achieve the damping curve that is needed, it does not matter what brand name is on the component. Once again, L2 and L3 are different due to stiction or drag in the seals and bushings, which is particularly high for telescopic front ends. Contrary to the fork’s controls, rear rebound damping is changed from the bottom of the shock. Coach Akkaya on Ducati 1199R, October 2018 (click for video), Can Akkaya’s old newspaper articles and race results, The suspension setting process provided here is a “Basic” methodical guide to providing a way to update you current suspension to the style of riding to best suit your needs. When suspension works correctly the bike will be much more enjoyable to ride. Compression Damping – Adjustments are made by turning the knob or, by turning the screw (2) depending on types of models. Medium to large bumps are felt directly through the chassis; when hit at speed, the rear end kicks up. It is NORMAL for a tire to lose about 1 pound per square inch (psi) per month. You want the chain at maximum extension – or with the front sprocket, swingarm and rear sprocket all in line with each other. There are trade offs that can be given for each adjustment that you make to your bike. Decrease compression until sliding stops and traction is regained. First, push down on the rear end about 25mm (1″) and let it extend very slowly. Damping cares about vertical wheel velocity, not bike speed. It’s important that you do not bounce! MAX EXTENSION You should check the chain tension with the bike on its wheels and preferably with someone sitting on it. Determining the style of the rider also affects the way your setup reacts for a particular person. A smooth rider will have a different setup compared to a point and shoot style of riding. It is all relative to you and your bike. Suspension-wise, heavy steering is a typical result of having rear ride height set too low, raking out the chassis like a chopper. As an additional note of caution: New tires tend to be very slippery when ridden for the first time. The best fork oil you can buy is the Redline fork oil. Before putting it all in, pump the forks up and down to circulate the oil throughout and remove any air trapped. Before attempting any setting changes, check to make sure your bike’s fork and shock are in good working order. The ride is plush at cruising speeds, but as the pace increases, the chassis begins to wallow and weave through bumpy corners. – Oversteering! Front end fails to recover after aggressive input over bumpy surfaces. It is recommended that an easy scrubbing in over 20-50 miles of riding. This will allow the tire to get rid of the mold catylist used for removing the tire and provide an initial heating which releases a layer of rubber to provide optimum traction. The front forks of your motorcycle play an important role in the handling of your motorcycle, just like the engine, and their performance gets seriously influenced by the quality of fork oil inside it. Model : Leg : Drain and refill amount: Refill amount if fork is fully clean & dry Front end dive while on the brakes becomes excessive. The same? Tech recommend OJ Racing Fork oil Type 01 which has the following specs: Viscosity at 40º C --> 15.06 mm 2 /s (cSt) Viscosity at 100ºC --> 3.472 mm 2 /s (cSt) Index of viscosity (VI) --> 106. Solution: Decrease compression “gradually” until bike neither bottoms or rides high. After hitting bumps at speed, the front tire tends to chatter or bounce. In the case of 15W-50 motorcycle oil, remember that a 10W-50 is still a 50 weight oil and will deliver the exact same protection in extreme heat. Use the handling scenarios and the chart to determine if you need to change your bike’s attitude. This is DAMPENING. Damping–viscous friction caused by forcing a fluid through some type of restriction. What is being illustrated here is that you MUST check your tire pressure on a regular basis (about once a week is reasonable) and to be particularly aware of it on cold days.        Solution: First off, the rebound adjusters as outlined in the setup section, and back the compression adjusters out to no more than the middle of their range. Take the bike off the stand and put the rider on board in riding position. And most importantly, squared-off or worn out tires will mask almost any suspension change you make. The latter is a big call, so we’ll stick with the string method – yep, this is ye olde “stringlining”, of which you may have heard your mates speak. The fork feels mushy, and traction “feel” is poor. If, however, the fork starts to bottom under braking with the preload backed off, the fork tubes can be raised in the triple clamps to sharpen the steering while keeping the original preload setting. – The rear wheel start to bump sideways under acceleration out of the corner. What weight are folks putting in as they change it? This measurement is L2. Doesn't that mean you want a 7.5-10 weight oil max? Start with the bike manufacturer’s recommendation in the owners manual or under-seat sticker.        Cause: These characteristics could be the result of a squared-off rear tire (too much straight-line riding) or notchy or too-tight steering head bearings;        Solution: if the bike has a steering damper mounted, it may be adjusted too tight. There is very little rear end squat. Take a close look at the various problem scenarios we’ve listed and see if one of them sounds similar to a dilemma you’ve been struggling with. When flicking the bike into a corner at speed, the front tire begins to chatter and lose traction.        Cause: The problem here is the ride height is set up correctly for his riding style, but the fork action is obviously too soft whenever weight is transferred to the front (as when hard braking). When rear end packs in, tires generally will overheat and will skip over bumps. – The front can feel unstable. As temperature goes, so goes pressure. If the rebound damping is cranked up to the maximum and the bike still feels soft and wallowy, you may need to rebuild the suspension components. With excessive rear end squat, when accelerating out of corners, the bike will tend to steer wide. Step 4: Do the number crunch: The spring sag is in the middle of these two measurements. Look for a high-VI fork oil. Preload Spacer–material used to adjust a fork’s preload internally. For example, trail drops off dramatically when the bike reaches full dive under braking, giving a rider more leverage to initiate steering inputs. When tire grip and lap times improve, the suspension has a harder job. It will slow steering because front end is riding high. If the same troubles occur after trying this bike with the steering damper backed off, checking his tire and adjusting his steering head bearings, the problem is most likely in his bike’s chassis attitude. – It feels like the front wheels will tuck under in corners. The front end has a mushy and semi-vague feeling–similar to lack of rebound damping. Chassis attitude and pitch become a real problem, with the front end refusing to stabilize after the bike is counter steered hard into a turn. Remember these are extreme examples; your symptoms may be more subtle. Often with stock components, when you turn the adjusters full in or out, you do not notice a difference. I am still in the process of rebuilding the front forks on Cal (my 1972 Harley-Davidson FLH Shovelhead), and I thought I would put together a quick FAQ about motorcycle fork oil – nothing ground shattering here, but certainly a list of reasonable questions that people sometimes ask.1. Generally, for a track bike with a steering damper, you’ll want to quicken the steering as much as possible by lowering the front end or raising the rear, while still retaining stability and without sacrificing rear end traction. I understand the technical difference between 5wt and 10wt fork oil is the viscosity, which is the ability of the fluid to flow at a defined temperature but is there much difference in the feel at the handlebar with similar damping settings dialled into the fork. Racers often use less sag to keep the bike clearance, and since roadraces work greater than we see on the street, they require a stiffer setup. Getting it all lined up will be a bit of a fiddle, but simple enough assuming the bike is straight.       Cause: The rough ride is most likely due to a generally too-stiff setup–with too much compression and rebound damping. Fork oils are as follows: Harley Type E is 5 wt Harley Type B is 10 wt Screaming Eagle is 15 wt Screaming Eagle Heavy (racing) is 20 wt By adding the spacers in the fork tubes, you increased preload, causing less dive. A forum community dedicated to Indian Motorcycle owners and enthusiasts. One word of caution regarding setup and tires: Don’t get dragged into adjusting your suspension to account for tire wear over the course of a track day without taking notes. Step 1: Extend the suspension completely and measure.  By getting the wheel off the ground. Record any changes you make so that you can refer to them later. Insufficient rebound. Note: We’ve also seen a tank slapping tendency produced by too much rearward weight bias. Once the rebound is set properly, the compression damping can be fine-tuned according to the setup section. Front end alignment. Motorcycle Fork Oil & Suspension Fluid from the UK's leading online bike store. With the preload set, take the bike for a spin to determine if there’s any change in its behavior. Peter, use the chart in FJ111200 post below to find an oil that has the same "Cst@40" measure and that you can get locally to you. Bumps and ripples are felt directly in the triple clamps and through the chassis. Suspension Fluid–used inside a shock absorber to create damping when forced through orifices or valving. Measuring front-end sag is very similar to the rear. This is often best done with two people, one working on each end of the bike. Damping Rod Fork–a simple type of fork that utilizes a tube with holes in it to create compression and rebound damping, delivering an extremely progressive damping curve. Symptom: Ride is generally hard, and gets even harder when braking or entering turns. Ride Height–suspension adjustments (raising or lowering the fork or lengthening or shortening the shock) to alter the chassis attitude of the motorcycle. Spectro Oils of America hereby states that it meets all American Made Motorcycle Manufacturer's warranty requirements set forth by the motorcycle manufacturer. Remember, don’t bounce! With bottoming, control and traction are lost. Track tire pressure is a different animal altogether. Of course, when all is said and done, I am going to have to refill the front forks. When you let go, the suspension should rebound quickly to its original position–but not beyond. Browse our range from brands like Castrol & Penrite. Where it stops, measure again. However, it’ much more critical to take seal drag into account on the front end because it is more pronounced. Lift up on the front end and let it drop very slowly. TOO MUCH COMPRESSION DAMPING (REAR SHOCK). – The rear “tops out” too fast under braking, causing the rear wheel to jump – The bike feels unstable. If the front compresses or rebounds different than the rear, attempt to match them, keeping within the parameters established individually. chickenhawk tire warmers also have a low temp setting where you can almost have the warmers on the low setting all day. The front end is compressing so low that the bike’s weight tries to pivot around the steering head, causing the side-to-side movement. If correct, then decrease compression “gradually” until chattering and shaking ceases. Stamped on the outside of many of your tires is a recommended tire pressure range. This causes poor traction over bumps under hard acceleration; the rear tire starts to chatter due to a lack of wheel control. ", 2001 Indian Spirit/ 2003 Bastard Son of Gilroy Scout /2017 Indian Springfield. If accuracy is important to you, you must take friction of the linkage into account. Problem: When Richard gets on the brakes aggressively while approaching a corner, the bike’s rear end begins to swap side-to-side, and feels as if it wants to pivot around the front. So, setting must be set harder. Decrease compression “gradually” until control is regained. (Gee, I wonder why they’re harsh?). Ride is harsh, but not as bad as too much rebound. – The rear “jutters” under braking. If your bike is topped out at rest, you need a stiffer spring, because you have got a lot of preload dialed in to achieve the correct static sag. This measurement is L2. Oil viscosity is graded by measuring the time it ... Read moreOil Viscosity and Weight Explained With Chart to Pick the Right One Anyhow, I've already filled one fork with 'B'. Available in a Standard 10wt Type E and Heavy Duty 20wt. Extend the fork completely by getting the bike off the ground and measure from the wiper (the dust seal atop the slider) to the bottom of the triple clamp (or lower fork casting on inverted forks; Figure 2). To the uninitiated–not that any Sport Rider reader could be accused of this–the language of motorcyclists can seem just as daunting. Decrease rebound “gradually” until harsh ride is gone and traction is regained. A sportbike should normally not use its full suspension stroke, although on some circuit one or two big bumps or hollows can cause the suspension to bottom. Street bikes run between 25 and 33 percent of their total travel, which equates to 30 to 35mm. Step 2: Downward Compression suspension with Rider on the bike and measure. High-Speed Damping–damping to control fast vertical movements of suspension components caused by road characteristics such as square-edged bumps. There is too much rear end “squat” under acceleration; the bike wants to steer wide exiting corners (since the chassis is riding rear low/nose high). This method of checking sag and taking stiction into account also allows you to check the drag of the linkage and seals. Spring Preload – Release the ring nut (4) by means of the appropriate spanner. The ride is overly harsh, especially at the point when bumps and ripples are contacted by the front wheel. – Can cause front to tuck under. If there is little or no change, gradually change the geometry by either raising the fork tubes in the triple clamps or–and has a rear ride-height adjuster–raising the rear of his bike. The first step to setting up any bike is to set the spring sag and determine if you have the correct-rate springs. You’ll get a lot of opinions on what tire pressure to run, but the correct tire pressure for you is not a matter of polling other rider’s opinion. Oil Weights. How to set your sag. Please note that these numbers tend to be too high for maximum traction but in turn increase the life of the tire. Check here for special coupons and promotions. Insufficient compression. This measurement is L1. When the oil level is lowered: The air spring in the later half stage of travel is lessened, and thus the front forks are softer. Topping Out–occurs when the suspension extends to its limit. Typically, damping rod forks have very little low-speed damping and a great deal of high-speed damping. Low-Speed Damping–damping to control slow vertical suspension movements such as those caused by ripples in pavement. You’ll enjoy smooth, squeak-free rides, and you won’t have to buy an expensive set of new forks because you forgot to keep them lubricated. Street riding entails many different pavement characteristics, and the road is generally bumpy compared to a racetrack, so it’s better to err on the soft side if you are unsure. Ensure the fork is standing vertically on a level surface. Worse? Since trail is dependent on rake, it is a variable dimension that changes proportionally with the variation of rake during suspension action. Problem: A tank slapping bike feels unstable, especially when entering turns. Symptoms: Front-end dives severely, sometimes bottoming out over heavy bumps or during aggressive breaking. Working with the front and rear individually, soften the damping adjuster, and try your bike again over the same road. If you’ve ever measured sag before, you may have noticed that if you check it three or four times, you can get three or four times, you can get three or four different numbers without changed anything. This means a shock creates no damping force unless there’s movement-movement of the damper unit in compression or rebound as opposed to bike movement. 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