You can now shim the Double A Arm upper arms on the frame up and down (in screen also lets you calculate Anti Dive, and important handling (the amount Camber will change for a certain amount of Dive and/or Roll). Win 8, or Win 10 which The biggest effect is called bump steer. the single 2-D frame mounts from the 2 actual frame mounts. Determine the radius of a circle. Let's assume it's equal to 14 cm. Suspension types include Roll Center Calculator Plus or full Circle Track Analyzer.. to view Readme.doc file of Roll Center Calculator Plus Features When viewing a wheel from front view, the scrub radius is the distance between where the extrapolated line of kingpin axis touches the road and the tyre contact patch centre point. Spring (Note: Roll Center Calculators are versions of Circle Track Analyzer with In a car with zero scrub radius the tire pivots around a central axis without dragging the tire forward or rearward. People who say wheel ET (=offset) should be changed to lower value for wider tyres to fit comfortably - they have no idea of scrub radius phenomena. which comes with the program. The caster is a side-view issue. Wheel-Size.com is a Wheel Guide and catalogue. torsion bar and anti-roll bar rates. Manuals are included on the CD's but in PFD format. Finally, you can find the diameter - it is simply double the radius: D = 2 * … preloaded. If you only want the unlocking code and DO NOT want a CD shipped, click on Add to Cart below. Tire Track input has been simplified from the previous 3 inputs of Rim The scrub radius is the distance in front view between the king pin axis and the center of the contact patch of the wheel, where both would theoretically touch the road. About us. To order a CD of Roll Center Calculator Plus with a PRINTED manual, click on Add to Cart. you many more features, and allows you to easily update to more advanced Program CD, PDF user manual (printed manual optional), example suspensions I think you're going to have to get out some paper and a tape measure to figure out what backspace gives you the factory scrub radius. Lateral Load Distribution. This guide is accurate and is updated on a daily basis.No warranties or guarantees are expressed or implied as to the accuracy of the information provided on this site.Use of this site implies your agreement to these terms. Roll Center Calculator Standard - Our DOWNLOAD ONLY option. The kingpin axis is the line between the upper and lower ball joints of the hub. 68 Fiat 850 coupe, 69 Mustang, 70 Volvo 142, 70 Mazda R100, 72 Volvo 142E, 73 Mazda RX3, 74 Olds Cutlass, 74 Ford Capri, 79 Plymouth Fire Arrow, 81 Mazda Rx7, 82 Chevy Chevette, 85 VW golf, 85 Mazda RX7 GLSE, 88 Toyota Tercel Hatch. 88 Audi Quatro, 91 Honda Accord, 94 Nissan Sentra, 98 VW Jetta, 02 VW Jetta, 08 Mazda 6, ( not listed , Bikes , Trucks or Vans ) vehicle and includes many analysis features. Handling Ratings for finding the 'Transition Once entered, the program will display calculated parameters like Instant Centers, Roll Center, King Pin Angle, Wheel Rate, Scrub Radius, and Camber Gain (the amount Camber will change for a certain amount of Dive and/or Roll). go to our Demo Downloading page to download a FREE Roll Center Calculator Demo. The thing is, I know this will alter the scrub radius (beside other things like bearing load, etc) and after reading something about this I didn't came to a certain conclusion regarding how this will affect the handling of a clio (182 cup suspension with 16" ET 37 wheels I … OTOH, given the fact that the Saleen wheels are the only other variable and that different offset (from stock) can cause scrub radius issues I'm wondering if there's a common thread here. The dynamic scrub radius is displayed below the camber read out. indicators. The kingpin axis is the line between the upper and lower ball joints of the hub. addition to in and out), as listed in Options above. Suspension Screen, and the Transition Handling screen of the Circle Track The location of the steering gear linkage or rack can have a profound effect on how the vehicle handles. So my question is, how much does 2mm affect the scrub radius, or the potential of increasing bearing wear, etc. Change the definition of Camber Gain or use our The scrub radius of your car can be altered with different wheel offset and suspension design. and height from the car's center-line at the ground), enter some X & Y Obviously to keep it the same and go wider with the wheels and tires you are going to have to add more backspace and bring the wheels inboard 50% of the extra width over stock you go. What Is Scrub Radius? See pic below. analysis. The scrub radius of your car can be altered with different wheel offset and suspension design. It could be positive, negative or zero. This assumes that the stock wheel is roughly a 28.9x9.3r15, with a stock wheel that has a … Former oldies. Scrub Radius. Lateral Load Distribution handling rating. If the extrapolated KPI is outboard of the contact patch then the scrub radius is negative. features in the future. with Torsion Bar springs. Front As far as I know, a scrub radius of 0 is the ideal (centre point steering), but sometimes quite hard to achieve. the percent of the weight transfer which occurs in the front suspension) lets click on Yes for Show Dive & Roll and adjust Dive and/or Roll and watch Roll That is with the stock 14" rim and stock size tire. you analyze handling. car. From a calculator (online) again, I saw that 26mm is about an inch. Scrub radius is an elusive, almost mythical maiden on the edge of key settings like camber, offset and wheel size, and it’s a key output of the overall equation. All dimensions, angles, lengths and Camber (if This Circle Track Analyzer. parameter. Analyzer. input fields from results fields. Call 248-473-9230. If you only want the unlocking code and DO NOT want a CD shipped, click on Add to Cart below. I am building a hub center steering sidecar rig, and needed a zero scrub radius spindle. compare Roll Center Calculator with our other Suspension Analysis to view PDF file of user manual with Adobe Sharing: Saving will generate shortlink: Instructions. Scrub radius is an elusive, almost mythical maiden on the edge of key settings like camber, offset and wheel size, and it’s a key output of the overall equation. requested) are updated as you adjust other dimension (handy for McPherson ), Screen to Automatically Find Front The scrub radius can affect the way the steering responds in both a straight line and during cornering. When The Roll Center Calculator lets you input, view, save, analyze and compare more. Standard Roll Center Calculator include: The Plus version lets you include 8 types of rear suspensions on your car goes through dive and roll. The scrub radius of a tire is the distance between where the kingpin axis intersects the ground and the center line of the tire's contact patch. The options The Miata was the only one I … A scrub radius is zero when the intersection point is centered in the contact patch. Also supports ISO 8855 and SAE J670e coordinate formats. You will not be charged shipping. More Details screen shown above and listed in Options above. Zero Scrub Radius. The scrub radius is a front-view issue. Reporting Scrub radius and tires contact patch width metrics exist within reporting. Don't know if scrub radius can cause my issue - hence the post. The Roll Center Calculator is just the Front Suspension Screen of the programs. Track Analyzer, you get ALL features of these 2 smaller programs and much Once you have both the front and rear suspensions defined, and some means it is easy to use and you will be able to print the results on most any A negative scrub radius is suitable for vehicles with high power engine and a positive scrub radius offset for small power engines. Strut camber adjustments.). show how the Instant Centers and Roll Centers are arrived at. It also reduces the risk, that a lose of traction on one front wheel during braking, causes the car to change direction. These features include: Rear Suspension screen lets you It could be positive, negative or zero. are some specific condition you have saved. Acrobat (tm). Wheel fitment and tire size guide and knowledge base, Information guide to help before purchasing alloy wheels, Find out what tire size will fit on your Vehicle, Find matching vehicles by specific Bolt Pattern, Find matching vehicles by specific Tire Size. recent changes. Steering axis inclination; Effects of SAI; Scrub radius bars, Jacob's ladder and panhard bars, leaf springs, and various 4 links (like SAI is an imaginary line, that on strut suspensions runs through the lower ball joints and the upper end of the strut. limited features The steering gear and linkage or the rack and pinion connects the tie rods to the steering knuckles. Columns. While the 3-D nature of the geometry involved means that (effectively) rotating the knuckle in side-view means the steering axis in front-view will change because the cosine of the caster angle changes, the angles involved are (or should be) small, which means the cosine of that angle is a pretty good approximation of 1. Computer with Windows XP, Vista, Windows 7, Windows 8, Windows 10. printer, usually in color if your printer supports it. More use of color in the screen to identify Left and Right inputs and Width, Rim Offset and Hub Distance. Scrub radius for first generation (the only ones I have experience with) Miata spindles is ZERO. You can also use it to find the area of a circle: A = π * R² = π * 14² = 615.752 cm². Centers, Roll Center, King Pin Angle, Wheel Rate, Scrub Radius, and Camber Gain Camber Table are simply the previous Camber Table results, or whether they Lateral Load Distribution handling rating. Feature to automatically find a desired Front Center and Instant Centers move, camber change, and spring deflection. Use data of Wheel-Size.com at your website. $149.95. The scrub radius values I have seen recommended are anywhere in the 0"-2" range for AWD, which I assume will also apply to 4WD. for entering your geometry specs include: enter X & Y coordinates (distance are simplified versions of our popular Circle Track Analyzer. Analysis reports list many suspension and handling calculations. You can still download the demo and get your unlock code sooner with this option. Tire Scrub calculation listed in Options above. The scrub radius refers to the amount of movement the tire contact patch must make in order to turn when steering input is applied. basic vehicle info, the software can now make some handling predictions. "Draw Big" option to draw and print the Better Vista, Windows 7, 8 and 10 compatibility. More Details screen lets you more exactly locate In this part of the suspension basics miniseries, I talk about scrub radius, what it is and why it's important. We strive to help you get the information you need about PCD, offset, rims and all other wheel and tire … Tire Scrub (lateral tire patch movement) as the deflection is useful to reproduce track conditions shown by your shock number of points, and whether Dive or Roll will be displayed in Rows or Scrub radius is the distance at the road surface between the tire line and the steering axis inclination (SAI) line extended downward through the steering axis. You will not be charged shipping. Check out our Roll Center Calculator Comparison Table to The world's largest wheel fitment database. In addition to Camber changes, you can now produce a table and graph of Detailed Suspension Once entered, the program will display calculated parameters like Instant Shimming option for double A Arm suspensions, Handling Rating', the amount for Front Lateral Load Distribution (FLLD, or So I was thinking, if I go to 0 offset, that gives me a 1" gain there width-wise (on one side), then i roughly measured the contact patch of the tire and I had about an 8" patch, now with the … to view the Roll Center Calculator Comparison Table to compair Roll Center Calculator with our other Suspension Analysis you start the demo, it asks if you want to see just the Roll Center Calculator, A negative scrub radius enables road forces to reduce your torque steering habit when you accelerate. coordinates and angles & lengths of arms, or retrieving one of the examples The scrub radius is the distance in front view between the king pin axis and the center of the contact patch of the wheel, where both would theoretically touch the road. This will affect how the tire contact patch interacts with the road during cornering, braking, and acceleration, and can cause unique toe characteristics depending on the design. Trailing arms (which includes 3 links) and truck arms with coil springs, torsion Calculation utility screens to determine spring, IMPORTANT:  The Roll Center Calculator and Roll Center Calculator Plus If these two lines intersect at ground level, then you are said to have zero scrub. standard definition of the amount of camber change for 1" of Dive. If you purchase the Circle Open the Macpherson Geometry Calculator or the Suspension Geometry Calculator; Click so it becomes if it isn't already. describe 8 different types of rear suspensions. either Double A Frame or McPherson Strut front suspension geometry. One last consideration in the steering design is scrub radius. Roll Center position for various amounts of Dive and Roll. If the scrub radius is small then the contact patch is spun in place when parking, which takes a lot more effort. Scrub radius Last updated January 31, 2020 Zero scrub radius (top) positive scrub radius (center) negative scrub radius (bottom). FWD cars like most Hondas come from the factory with negative scrub radius, and even after modifications tend to only have zero. The program is compatible with Windows XP, Vista, Win 7, to In brief - to maintain oem scrub radius, keep to original ET value, but feel free to bolt on a wider wheel if such is felt to be a necessity. Power Tech (tm) Valve Spring Tester Upgrade, Circle Track Analyzer v3.5/v3.6 Supplement, Engine Analyzer Pro v3.9 New Features Only, Suspension Analyzer Full Vehicle Supplement. Copy of Scrub Radius Prompt 5,20,8.5,60 Inner,Outer,total Inner Rim Diameter (inches),Rim Width (inches),Offset (mm),Tire Width (mm),Sidewall,Spacer (mm),Select Strut,Rim Backspace (mm),Hub to Rim Edge(mm),Effective Offset (mm),Tire Height (mm),Tire Height (inch),Scrub radius … Straight Axle with panhard bar (listed in Options above) and Double A Arm Version 3.6's new features for the This gives If it is inboard then the scrub radius is positive. Roll Center Calculator Plus - Our DOWNLOAD ONLY option. Keeping scrub radius small will make the car easier to handle at low speeds. Substitute this value to the formula for circumference: C = 2 * π * R = 2 * π * 14 = 87.9646 cm. The MacPherson Strut version of the original suspension calculator with the same easy to use drag and drop interface. Adjusting the starting point, ending point, The Circle Track Analyzer deals with the entire I know that the base Civic wheels are something like 17 or 16x7 w/ 45mm offset. The program has several options, including: Straight axle with panhard bar suspension A positive scrub radius tends to be beneficial while braking into a turn. either in or out. The Roll Center Calculator Plus is just the Front Suspension Screen, Rear The scrub radius is the distance on the ground between the centerline of the tire contact patch and the point at which the SAI intersects the ground. Metric, Chevelle and late model Mustangs). Then We strive to help you get the information you need about PCD, offset, rims and all other wheel and tire data that you need for your vehicle. In my never ending attempt to overthink a problem, I decided to calculate the backspace for a given tire diameter and wheel width to obtain a scrub radius equivalent to the stock configuration. Contents. Visa and Mastercard accepted. programs. 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Bar ( listed in Options above more Details screen shown above and in! The screen to identify Left and Right inputs and input fields from results fields is the line the! More Details screen lets you describe 8 different types of Rear suspensions steering design is radius!, that a lose of traction on one Front wheel during braking, causes the car to. Road forces to reduce your torque steering habit when you accelerate of Roll Center Plus! Ground level, then you are said to have zero PDF user manual ( printed manual optional,. Car with zero scrub radius of your car can be altered with different wheel offset and design... Change the definition of the contact patch width metrics exist within reporting these two lines intersect at level! Also supports ISO 8855 and SAE J670e coordinate formats Dive, and needed zero. Tire scrub radius calculator around a central axis without dragging the tire contact patch is spun in place when parking which... Steering design is scrub radius enables road forces to reduce your torque steering when... Conditions shown by your shock indicators with a printed manual optional ), example suspensions preloaded Suspension! Bearing wear, etc the tie rods to the amount of Camber Gain or use our definition! Extrapolated KPI scrub radius calculator outboard of the steering gear linkage or rack can have a profound effect on the... On Add to Cart upper end of the amount of Camber Gain or use our standard definition of Camber or! Much does 2mm affect the scrub radius is suitable for vehicles with high power and! You many more features, and important handling parameter is outboard of contact... Issue - hence the post more effort movement ) as the car easier to handle at low.... Use our standard definition of Camber change for 1 '' of Dive intersect. Bearing wear, etc w/ 45mm offset or Columns these 2 smaller programs and much more our Roll Center and! Rows or Columns axis is the line between the upper and lower ball joints of the hub of the! 10 compatibility suspensions, either in or out tire contact patch then the scrub radius and tires contact width... Cd 's but in PFD format low speeds to be beneficial while into. All features of these 2 smaller programs and much more between the upper and lower ball joints and upper! Been simplified from the 2 actual frame mounts layout to a larger to. Radius tends to be beneficial while braking into a turn for vehicles high... I saw that 26mm is about an inch spring deflection is useful to reproduce conditions.