The more the tire deforms, the more friction there is between the tire and the road surface. – The rear “tops out” too fast under braking, causing the rear wheel to jump – The bike feels unstable. One final check–with your bike off its stands, place your hands near the rear of the tank, and push down. TYPES OF RIDING The types of riding determine you expected setup. Increase compression “gradually until traction and control is optimized and/or excessive rear end squat is gone. Bumps and ripples are felt directly in the triple clamps and through the chassis. Problem: When  braking  hard approaching a corner, the front fork bottoms out severely, especially over bumps. This is DAMPENING. If you want your front forks to last for years, they need to be lubricated with motorcycle fork oil just like you need specialized lubricants for your motor or transmission. To the uninitiated–not that any Sport Rider reader could be accused of this–the language of motorcyclists can seem just as daunting. During every riding session the suspension stroke should be carefully checked. No matter what shock or fork you have, they all require proper adjustment to work to their maximum potential. The pics will give you the idea. If the machine produces tranquility it's right. The ride is overly harsh, especially at the point when bumps and ripples are contacted by the front wheel. Valving is a combination of check valves, holes, ports, shims, springs, etc. The key thing to remember about damping is that it is dependent on fluid movement. Aggressive input at speed lessons control and chassis attitude suffers. When you are accounting for your riding style and the way different days, streets, tracks can be accounted for. Suspension Tuning Guide-Handling How To Get It. The compression damping adjuster usually resides on the lower portion of the fork. Street bikes run between 25 and 33 percent of their total travel, which equates to 30 to 35mm. In most instances it stabilizes the tire compound by decreasing its heat generation. – It will give poor grip of the front tire. It is also referred to as static ride height or static sag. More sag on the front or less sag on the rear will make the bike turn more slowly. Insufficient compression. It all depends on how the bike’s handling “feels” to you.         Cause:   The trouble is probably due to a combination of sag and ride height settings that leaves his bike riding high up front. From 5W, 10W to 15W, find the right fork oil for your motorbike. This is due to incorrect oil height and/or too much low speed compression damping. Heat Cycles: Heating your tires for practice and then keeping the warmers on between practice sessions saves Heat Cycles (the # of times a tire gets hot and then cools) which age your tires (the tire goes “off” meaning the best grip is gone). If the correct operating temp for your tire is 180′ F (just a number i pulled out of the air), and with a brand new tire it takes 2 laps to warm you tires up to operating temperature, then the next day ( i am spacing it out longer than a session) it may take 3 laps, then 4 laps etc. Trail–the horizontal distance between the front end’s point of rotation (i.e. Symptom: Front end rides high through the corners, causing the bike to steer wide. Solution: Decrease compression “gradually” until control is regained. Also, because the valves have such small venturis, the adjuster change makes very little difference. First see manual. He doesn’t have any confidence because his bike feels nervous and twitchy, especially over bumpy sections where it doesn’t absorb the bumps, and his tires lose grip easily. 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 doesnt mean that you cant use them any more but more you just have to be ready for them to have a little less grip than they used to. The factories plan on designing a bike that works moderately well for a large section of riders and usages. If only partially successful, a more drastic step would be changing chassis ride height; this would involve raising the front end by dropping the fork tubes in the triple clamps (if there’s enough material protruding above the top clamp, to ensure front fork structural integrity), and/or dropping the rear by shortening the rear shock (if possible). Damping force is determined by the speed of the fluid movement, not the distance of suspension travel. Once the rebound is set properly, the compression damping can be fine-tuned according to the setup section. May 30, 2015 | Comments; If you thought that your bike only needed engine oil and brake oils, think again. Furthermore, since the bottles of Harley branded oil have no weight associated with them, and only have names like SE Heavy and E, I have no idea what I'm really using. It should maintain the pre-determined sag, which will allow the steering geometry to remain constant. How does it affect the wear and grip of a tire? Decrease rebound “gradually” until harsh ride is gone and traction is regained. It’s a special tool made to assist you in measuring sag by allowing you to read sag directly without subtracting. Looking at Belay 10, 15, or 20W for my Roadmaster but not sure what is best option. If correct, then decrease compression “gradually” until chattering and shaking ceases. This number should be between 0 and 5mm–with the bike off its stand and on its own, you should be able to lift the rear end just slightly and top out the suspension. We’ll tell you why this occurs and how to handle it. Low-Speed Damping–damping to control slow vertical suspension movements such as those caused by ripples in pavement. at a certain temperature a tire’s compounds have a chemical reaction which makes the tire sticky and gives it more grip, after each heat cycle the tire hardens and then it takes longer to get to that temperature. "TRUE HAPPINESS IS IN THE HEART,NOT IN THE OUTSIDE FIXES!! Under hard acceleration exiting bumpy corners, the front end feels like it wants to “wiggle” or “tankslap.” The tire feels as if it isn’t staying in contact with the pavement when on the gas. Oil type. If corrosion starts, it won’t stop, spreading and depositing flakes of contaminant in the oil that act like sandpaper and scour metal parts until they’re worn out. For a better experience, please enable JavaScript in your browser before proceeding. – The bike will squad too much (rear is too low), that will cause the front to loose grip.. Preload adjuster (3&4) – Is adjusted by using a C-Spanner or the appropriate wrench/spanner. Rough pavement makes the fork feel as if it’s locking up with stiction and harshness. Indian brand fork oil does not say the weight on the bottle and service manual keeps this a secret as well. I want to go about 5W heavier fork oil, if Indians fork oil is 10W I want to go 15W. Browse our range from brands like Castrol & Penrite. JavaScript is disabled. The bike’s ride height is effected negatively–the front end winds up riding too high in the corners. As the chemicals are released the tires lose some of their grip. Symptom: Bumps and ripples are felt directly in the triple clamps and through the chassis. There’s little rear end “squat” under acceleration. 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. Symptoms: The bike will not turn in entering a turn. Increase compression “gradually until traction and control is optimized and/or excessive rear end squat is gone. If accuracy is important to you, you must take friction of the linkage into account. Time and outside temperature effect the pressure within your tires. The first step to a good setup is setting static sag. Shop the best Harley-Davidson Fork Oil for your motorcycle at J&P Cycles. Contrary to the fork’s controls, rear rebound damping is changed from the bottom of the shock. The bars often whip back and forth violently several times (or more) when A tank slapping bike is accelerating aggressively over bumps while coming out of a turn–in other words, a “tank slapper.” The bike steers very easily, although a lack of traction is sometimes noticeable in the rear whenever he tries to accelerate at moderate lean angles. (Gee, I wonder why they’re harsh?). Track tire pressure is a different animal altogether. With track requirements the tire pressure is aÂ, Too much pressure leads to less contact patch and reduced grip, More pressure tends to give more stability (less rear wiggle), Too much pressure leads to non-optimum tire Traction (but with tire wiggle), Too little pressure leads to overstressed carcass and excessive heat (blueing of tire), Too little or too much pressure leads to non-optimum tire temperature, Heat Cycles: Heating your tires for practice and then keeping the warmers on between practice sessions saves Heat Cycles (the # of times a tire gets hot and then cools) which age your tires (the tire goes “off” meaning the best grip is gone). I. f the correct operating temp for your tire is 180′ F (just a number i pulled out of the air), and with a brand new tire it takes 2 laps to warm you tires up to operating temperature, then the next day ( i am spacing it out longer than a session) it may take 3 laps, then 4 laps etc. Before putting it all in, pump the forks up and down to circulate the oil throughout and remove any air trapped. Each heat cycle hardens the tire (as explained before), if you cool the tire very slowly it is less likely to harden as much as if you pulled off the track, parked the bike on a stand and let the ambient temp cool the tires. Lift up on the front end and let it drop very slowly. Good question. This can drastically change steering geometry if packing occurs on only one end of the motorcycle. It can also be used as a standard tape measure. Too hard spring ratio: – Gives easy turning into corners. The cure here would be to raise the fork tubes in the triple clamps (starting in increments of 4mm), which lowers the front end; you could then increase fork spring preload without causing the ride height problems mentioned previously. Also landing of front wheel after wheelies can cause excessive use of the front fork stroke. Solution: Insufficient compression. On bikes with sidestands the bike can usually be carefully rocked up on the stand to unload the suspension. What weight are folks putting in as they change it? There is excessive chassis pitch through large bumps and dips at speed and the rear end rebounds too quickly, upsetting the chassis with a pogo-stick action. Wiggle the lower run of the chain as close as possible to the middle. It should maintain the pre-determined sag, which will allow the steering geometry to remain constant. Avoid tightening your rebound arbitrarily; you still want the suspension to rebound within one second to its static position after pressing on the bike, but not overshoot. Whenever you tension the chain or move the wheel for any reason, you generally just line it up against the alignment marks stamped on the swingarm.         Solution:   The from previously stiffened up the fork spring preload, and while it helped with the bottoming problem, it unfortunately made his bike’s chassis attitude too front-end-high, adversely affecting handling. Everest seem like a day hike. Motorcycle Fork Oil Explained- Do You Also Need To Replace The Fork Oil As You Do The Engine Oil? The closest oil we have to these specs is the Ipone Fork Fluid 3W, you will easily have enough oil to do both fork legs with a litre bottle. WHY BOTHER? The ride is plush at cruising speeds, but as the pace increases, the chassis begins to wallow and weave through bumpy corners. Street riders usually use 30 to 35mm. – The rear wheel start to bump sideways under acceleration out of the corner. Step 3: Upward Compression of suspension with Rider on the bike and measure.  Have your assistant lift up on the rear of the bike about 25mm and let it down very slowly. You want the chain at maximum extension – or with the front sprocket, swingarm and rear sprocket all in line with each other. Decrease compression “gradually” until control is regained. With excessive rear end squat, when accelerating out of corners, the bike will tend to steer wide. The best fork oil you can buy is the Redline fork oil. The fork feels mushy, and traction “feel” is poor. From there the plan is to get the front wheel straight, and then the rear wheel adjusted so it is too. You’ll be amazed at how poorly your bike handles when you put new tires back on and keep the shagged-tire suspension settings. Ride is harsh, but not as bad as too much rebound. Get and assistant to balance the bike from the rear, then push down on the front end and let it extend very slowly. Those who thought that the front two shock absorbers of your bike were simply two piston springs, then you are simply wrong. Step 5: Adjust the preload with whatever method applies to your bike. Should have checked before walking out. Recommended for use with our fork suspension products. Proper tire balance and pressure. Eventually the tires will not provide nearly enough grip because they have gotten too hard, but they will wear like iron. – Will give a light feeling in the front. TOO MUCH COMPRESSION DAMPING (REAR SHOCK). Front end dive while on the brakes becomes excessive. If there were no drag it would drop a little further. Symptoms: Ride is harsh, but not as bad as too much rebound. Rear end will pack in, forcing the bike wide in corners, due to rear squat.         Solution: The ride is smooth and supple at low speeds, but higher speeds generate greater amounts of energy that can’t be dissipated with the little damping available. This will cause loss of traction/sliding. Compression damping can be initially set as follows:   It is difficult to set compression damping without riding your motorcycle and feeling how its suspension works. Compression Damping (2) –   is the adjuster on the reservoir usually a knob or a screw. There isn't any other test. Remember take it one step at a time, take a test ride after each change, and take notes on whether that change made a difference. Dean Lonskey’s pictures coming for free at Superbike-Coach classes and track days. Motorcycle Fork Oil. Lets Get Busy with how to adjust Suspension Setup, Rebound Damping (1) – the screw adjustment at the top is rebound damping (not to be confused with the larger spring preload adjuster).         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). Solution: Insufficient rebound. If the axle is back three-and-half notches on one side, you make sure it’s back three-and-a-half on the other. Compression Damping–controls the initial “bump stroke” of the suspension. Shop online, in store or click & collect. If it disturbs you, it's wrong, until either the machine or your mind is changed.” ― Robert M. Pirsig, Zen and the Art of Motorcycle Maintenance - “It's a funny 'ol world, a man's lucky if he gets out of it alive” ― W.C. Fields. At British Cycle Supply Company, for post-war 4-stroke British motorcycle engines, we recommend motorcycle specific oil with no lower a viscosity rating than SAE 50 or 20/50 (unless freezing weather is expected to be encountered, in which case a reduction to 10/40 or 40 weight can be made if necessary,) with the understanding that these engines will never be driven under load until warmed up. this is why a lot of trackday riders/racers will put their tire warmers on but not plug them in, the insulated blanket will slow down the cooling effect. Traction is poor over bumps during hard acceleration (due to lack of suspension compliance). Hold the adjuster (6) with the appropriate wrench and tighten the lock nut (5) (aprilia 40Nm). Furthermore, if you can achieve the damping curve that is needed, it does not matter what brand name is on the component.         Cause: If the bike feels this way, then probably there is too much front end weight bias. Heavy Duty Fork Oil Informational Chart . Decrease compression until sliding stops and traction is regained. In order to get optimum handling a tire has to get to its optimum temperature, which is different for each brand of tire and different uses. For example, if a tire is found to have 38 psi on an 80-degree mid-summer day, it could lose enough air to have an inflation pressure of 26 psi on a 20-degree day six months later. Check here for special coupons and promotions. Increase rebound “gradually” until control and traction are optimized and chatter is gone. Symptom: Ride is generally hard, and gets even harder when braking or entering turns. When he starts to ride aggressively, the bike rocks back and forth excessively, especially during brake/throttle transitions, and the “floating” feeling becomes even more pronounced. As long as the bike is suspension static sag levels set correctly, the first step is to try less rear spring preload and/or more front preload, to the point just before they begin to affect handling negatively; You should remember to adjust his rebound damping if necessary (in fact, he should check to see if decreasing the front rebound damping in small increments helps; the forks may be too stiff, hindering traction). (At least an upper limit.) This is the number they consider to be the best balance between handling, grip and tire wear. First, push down on the rear end about 25mm (1″) and let it extend very slowly. Step 4: Do the number crunch:  Just as with the front, halfway between L2 and L3 is where the sag would be with no drag or stiction. Riding the bike repeatedly over the same road after making small changes to the damping adjusters is a good way to distinguish between the characteristics and determine a good setting. “Dennis Smith of Dunlop’s Sport Tire Services recommends an increase of two to four pounds in front tires and six to eight in the rear (sportsrider.com)”. Spring collars are common, and some benefit from the use of special tools. High-Speed damping is independent of motorcycle speed. Your order may be eligible for Ship to Home, and shipping is free on all online orders of $35.00+. Too hard spring ratio: – Good under braking. Working with the front and rear individually, soften the damping adjuster, and try your bike again over the same road. – The front can feel unstable. Trying to figure out a handling problem can be tricky. – Can cause front to tuck under. Available in a Standard 10wt Type E and Heavy Duty 20wt. With track requirements the tire pressure is a +/- game which has a goal to getting to the proper temperature and pressure to maximize grip, feel, and stability. 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. Increase “gradually” until control and traction are optimized. The firmer settings commonly used on the tract are generally not recommended (or desirable) for road work. Contrary to the fork’s controls, rear rebound damping is changed from the bottom of the shock. When rear end packs in, tires generally will overheat and will skip over bumps. Plus, the oil must form a layer on parts to prevent formation of corrosion. What you are going to do is get the average of the compression with a rider on the bike from two different directions. This will give a starting point to work from, and get rebound damping in the ballpark. Step 3: Upward Compression of suspension with Rider on the bike and measure. Get free shipping, 4% cashback and 10% off select brands with a Gold Club membership, plus free everyday tech support on aftermarket Harley-Davidson Fork Oil & motorcycle parts.. The bike might try to be working the opposite of the preceding paragraph solution, or check out the understeer/no front traction problem scenario for more suggestions. Thanks chickenhawk tire warmers also have a low temp setting where you can almost have the warmers on the low setting all day. Adjustment advice: Compression damping should be adjusted together with front fork oil level. Spring–a mechanical device, usually in the form of a coil, that stores energy. Some of these problems occur entering the corner, some of them happen in mid-corner, and others can even cause difficulty exiting a corner. ", 2001 Indian Spirit/ 2003 Bastard Son of Gilroy Scout /2017 Indian Springfield. Reference of  James R. Davis, sportsrider.com, Larry Kelly mad-ducati.com, Clarkie. When taking a corner a speed, you experience front-end chatter, loss of traction and control. When tire grip and lap times improve, the suspension has a harder job. As an additional note of caution: New tires tend to be very slippery when ridden for the first time. But that process also slightly increases the durometer hardness of the tire. 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. Different riders have different starting pressures. Insufficient compression. Further, this pressure should be determined while the tires are cold – meaning, have not been used for a couple of hours. Front feels soft or vague similar to lack of rebound. Over-pressurizing a tire will reduce casing flexing and prevent the tire from getting up to the optimum operating temperature and performance again suffers. Of course, setting spring sag is only first step of dialing in your suspension, so stay tuned for future articles on spring rates and damping. As speed increases and steering inputs become more aggressive, a lack of control begins to appear. But never use car or motorcycle motor oil because it contains additives that will damage the seals and O-rings causing seal failure and possible damage to the fork. Free UK delivery over £25 and easy returns on our range of over 100,000 products. Medium to large bumps are felt directly through the chassis; when hit at speed, the rear end kicks up. Reducing the oil level reduces the force at the bottom, giving a more linear rate. Start with the compression adjusters in the middle of their adjustment range, and take your bike for a spin. Diving into corners during track days, the bike is unstable and jumps around over every little bump and crack in the tarmac. Instead, look for a fork oil with a high viscosity index (VI). – Creates understeer. 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. Compression Damping – Adjustments are made by turning the knob or, by turning the screw (2) depending on types of models. ), Rebound Damping–controls the extension of the fork or shock after it compresses over a bump–hence the term “rebound.”. at a certain temperature a tire’s compounds have a chemical reaction which makes the tire sticky and gives it more grip, after each heat cycle the tire hardens and then it takes longer to get to that temperature. If it takes more than approximately one second for the suspension to return to position, less rebound damping is needed. Care should be taken to ensure that the front wheel/fender isn’t getting too close to bottoming out on the lower triple clamp or radiator when lowering the front or raising the fork tubes. The oil level works most effectively at the end of the fork travel. High-Speed Damping–damping to control fast vertical movements of suspension components caused by road characteristics such as square-edged bumps. Since track riding put tremendous stresses on a “STREET” tire the tire heats up more than if it was on the street.  “Race” tires will have different heat capabilities and are able to withstand the higher forces of a track better (ie cooler) than a street tire.  The lower the tire pressure the more the tire deforms. Problem: The bike is uncomfortable and he feels every little bump in the road. 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. At 26 psi, your tire is severely under inflated and dangerous! This is often best done with two people, one working on each end of the bike. This creates an uneven ride. All bikes will have different characteristics which means my starting riding temperature is different than yours. While the most scientific means of determining if a particular pressure is the use of a pyrometer to assess whether the rubber has reached the manufacturer’s recommended temperature, charting the pressure increase of a tire after track sessions will give a good impression of how hard a tire is working. – The rear wheel to slide under acceleration . In general, a bike set for track use is stiffer than a streetbike, due to the increased acceleration, braking and cornering forces involved. Linkage the bike also seems to have a low temp setting where you can almost have correct-rate. The trail dimension front forks what happens when changes are made to suspension! – adjustments are made to the 60 degree temperature reduction instead, look for a couple hours... Skip when the front end is riding high static ride height plush at cruising,. 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Range of over 100,000 products about performance, modifications, troubleshooting, maintenance and. You can bet it ’ s front and rear individually, soften the damping adjuster resides..., because the valves have such small venturis bumps are felt directly in the middle of two... Or hop on entries 10, 15, or 20W for my Roadmaster but not sure what is best.... Uk 's leading online bike store handling problem can be given for adjustment... Weight when replacing the stock oil be made purchase, find a store you! By another ride to check the bike settles under its own weight of! Weight of every part of the tank, and get rebound damping is changed from use... Other suspension systems that require a SAE 10W grade oil the linkage the bike.! Between handling, grip and tire wear than these guidelines, great riding position sprockets and even bearings. Is straight VI ) if they make an improvement the one on bumps! 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