distance a tire travels in one revolution. The easiest way to measure this distance is using a string. Tire Size Calculator calculates tire dimensions, diameter, circumference, revolutions per mile/km from the tire size designation. Thanks for any help on this matter. Calculations are to be treated as approximate only, due to possible and probable variations in how tires are manufactured, as well as usage and wear. Tire Size Chart - Metric - by Rim/Wheel Diameter displays the metric tire size designations with belonging tire measures: OD - Overall Tire Diameter, SW - Section width, AR - Aspect Ratio, RD - Rim diameter, SH - Section height, CI - Tire circumference, RE - Revolutions per mile/km; in metric and English units.. Follow Group Number Column Right until reaching Row Spacing or Application. I am currently ruunning a 18.4 x 30 rear and a 12.4 x 24 front (bias) on a NH TL100. 380/90R46) Find Group Number for Front and Rear Axle on RCI chart (E.g. When selecting tires for your MFWD tractors, you want to make sure to maintain the proper ratio of rolling circumference for your tractor. Secure the end of the string at the starting point and wrap it around the tire. Ag Tire Talk does not recommend anyone conduct tire service work with exception of Certified Ag Tire Dealer Professionals. Several sizes are often possible with a particular type of tractor, as long as one remains within the lead range. The standard method of size expression is relatively simple, but not as descriptive as metric.An example of tractor tire sizes expressed in the standard format would be “14.9-42”. × OK. Join Our Mailing List for special offers! www.sacoronavirus.co.za. RCI Group, within RCI Chart, is used to make changing tire widths easy, with all tires in same group maintaining virtually same overall diameter, displaying size options that will fit equipment along with application. The calipers will allow you to extend down the sidewall to measure the maximum width of the tire. Posted by James Tuschner | May 12, 2016 | Size Options | 10 |. 80 mph. OPTITRAC . Tractor Tire Size Conversion Chart Tractor Tire Sizes and their Metric Equivalent. Standard, Radial, and Metric Tractor Tire Sizes. Because your measurements are of a used tire, you may not find a new tire with the exact same dimensions. Rears are 13.6 x 16 with calcium. 2 List of Tyre Sizes TYRE SIZE TREAD PATTERN PAGE TREAD PATTERN PAGE TREAD … Use the formula given below: front tyre rolling circumference x gear ratio % front wheel lead = - 1 x 100% rear tyre rolling circumference Determining the gear ratio View details. Wishlist; Login or Sign Up; Shipping & Returns; Quick Links. Thank You, If you do not have a wide set of calipers, you can recruit a friend to hold a pair of straight edges like a 2x4 on both sides of the tire and have the gap extend past the tread area. and 1546 mm (60.9 in.). If you can’t read the tire size from the sidewall, you can manually measure the tire. For more information on what cookies we use and how to manage these cookies please visit our. Check out five reasons your farm should switch from bias to radial tires. Which front and rear would you put on? Rolling circumference can be defined as the . © 2020 Bridgestone Americas Tire Operations LLC All Rights Reserved, This site uses cookies to enhance your user experience. Mark the string where it intersects the starting point. Thank you for comment, Required fields are marked *, Designed by Elegant Themes | Powered by WordPress. I want to go to a 380/85R24 radial (front) and possibly a 480/70R34. You can calculate forward movement if you know the circumference of the front and rear tyres, as well as the transmission ratio of the tractor. Even the best tractor you own can be rendered useless, if the wrong tire size is installed. As you are wanting to increase overall diameter of tires, along with increase section width of front tires, I cannot tell you with certainty combination will work- you may have clearance issues with rear fender overhang, along with possibility of tire rubbing under tight steer with wider profile. Below is Example of Group 46 Alternate Sizes: As shown above, in Group 46 (73″ overall diameter): Below is an example of an RCI Chart from Goodyear Titan: *Please note manufacturer RCI Charts only contain tires sizes produced by that specific manufacturer. Once you find a tire size the last decision you will need to make is if you want the tire in a bias or a radial construction. I have a JD 750, 20yrs old with turf tires on it that need replaced. Could you please provide year and model number of your Spra-Coupe? On pavement, radial tires have shown up to 33% better wear life than the same size bias-ply tire. If you fit a tyre size to your vehicle that has a larger or smaller rolling circumference it will make your vehicles speedometer read incorrectly. Will a 380/85R24 fit on the same rim? See complete definitions of rolling circumference and section width at https://agtiretalk.com/ag-tire-glossary/. By continuing to browse our website, you agree to use these cookies. All information is provided in this blog solely to provoke thought. Let’s take the typical (MFWD) tractor with 480/80R50 rears and 420/85R34 fronts. Tire Circumference Chart Please use this chart for your reference. BK 823 is a tire designed for tractors, implement and trailers mainly in soil tillage and haulage applications both in the fields and on the road. UNDERSTANDING ROLLING CIRCUMFERENCE. Once you have these measurements, you can use the Databook to find a tire that has a similar diameter and section width. Sign up to receive emails about product information, special offers and events. For the section width of the tire, you want to measure the maximum width of the tire which is usually found in the sidewall not the tread. Email Address. BIAS . we have a 1987 CIH 7120 with 13.6R28 on the FWA front and 18.4R38 on the rear. The approximate overall diameters for each group are shown in the table. Just type in a metric or standard size tyre and click calculate. It is acceptable to increase or decrease the overall diameter on the rear tires, but the front tires will also need to be changed. The difference in rolling circumferences between the front and rear tires must be between 1018 mm (40.1 in.) Bias-ply tires have a stiffer sidewall that is less prone to lateral deflection and are less expensive. For example, Goodyear Titan RCI Chart will only contain Goodyear Titan sizes. On Mechanical Front Wheel Drive (MFWD or FWD) tractors, the rear and front tires must maintain a proper rolling circumference ratio. To maximise the potential of four-wheel drive, the rolling circumference of the front tyres must be less than that of the rear tyres; the so-called lead. The level to which it is being misrepresented is based on how much different the new rolling circumference is. 225/45-R17. Use the Rolling Circumference Index (RCI) Chart! Fronts are 25 x 8.50-14 Will this combo work on my TL100? Tyres. On a Magnum 340 RT with 21 inch tracks can you put a 520 85 R38 on the front. The Traxion+ tyres in the “low section” category are wider tyres with the same rim diameter as the standard Traxion85. VersaBuilt tires have built-in advantages. The special dual-angle lug design pro ... Construction. Tredz Central 3200 US Hwy 77 Cortland, Ne 68331. As if the gibberish wasn’t cryptic enough, there are actually two ways that manufacturers can express their tractor tire sizes. On Mechanical Front Wheel Drive (MFWD or FWD) tractors, the rear and front tires must maintain a proper rolling circumference ratio. One method uses the “standard” format and the other is the “metric” format. We are going down to 20 inch rows. Use this page to work out the radius, circumference and diameter of any size tyre. Please contact your Local Certified AG Tire Dealer to assist with options. Tires are given the same RCI number or group size designation (regardless of tire width or rim diameter) if their rolling circumferences are similar. Since this measurement is hard to measure with just a tape measure, a wide pair of calipers is recommended. I am wanting to run single rubber for 30 inch middles plus have extra flotation for rice ground without always switching my duals on and off. Whatever the machines you work with, tractor, trailer, combine harvester, spreader, sprayer, tank trailer or machines for harvesting, treatment or maintenance, take advantage of the Michelin group’s full and specialised range of agricultural tyres. Tractor Tire Size Conversion & Tube Chart This chart is meant to be used as a reference only as to how tractor tire sizes have changed and convert. You are correct, keeping same overall diameter of tires is critically important. Mitas tractor tyres are the most numerous group with new radial products such as tyres in the VF (Very High Flexion Tyres) category, the SFT tyres where you can find the largest mass-produced Mitas tyre – the 1250/50R32, and Mitas SST (Silent Speed Tyres) with their special reinforced steel construction. Rolling circumference is the measurement of the distance a tire travels in one revolution. The rolling circumference (RC), in turns, is further considered as input in various vehicle dynamics calculation like traction force calculation and grade ability calculation.The formula used here is … Tractors are normally accompanied by information about the most suitable standard tyres. Now measure the length of the string which will be the tire’s circumference. AG TIRE SIZE OPTIONS / CONVERSIONS: Why, When, How ? RD Tractor Radial Drive.....8 TD Tractor Drive (diagonal).....16 AR Agricultural Radial .....20 IM Implement Non Traction.....22 TR Implement Traction.....26 TS Tractor Small .....30 TF Tractor Front .....34 B Bantam .....36 Contents 1 Mitas AGRI-08-GB.qxd:Mitas AGRI-08-GB 25.11.2008 14:35 Page 4. I reviewed the RCI Charts. Thank you for asking, as long as different ag tread design is the EXACT SAME SIZE TIRE, along with EXACT SAME PLY RATING (load carrying capacity), this should work no problem with your existing wheels. This measurement will be the section width of your tire. The information in the Required area is needed to perform the comparison. 44. Dimension of original tire / Dimension of new tire / 195/65-R15. Inch measurement tyres are fairly easy to understand however metric tyres use a more difficult system to read. Find out more by reading this article on Tube-Type and Tubeless Tyres. Rolling Circumference Index Chart, or RCI Chart categorizes farm tires in accordance with overall diameter / rolling circumference along with section width / row spacing. Accounts & Orders. As always, we recommend you take recommendations to a Certified AG Tire Dealer to confirm all, and set up properly: ballast, clearances, air pressures, check wheel for damage, etc. Ascertain the Following Data 1. Due to the increase in mechanical front wheel drive (MFWD) tractors in the marketplace, it is very important to understand rolling circumference when trying to determine the proper tire setup for your tractor. Calculator; 4x4 Driving Tips; Testimonials ; UPDATE - ADJUSTED Level 3 From Tuesday 29th December 2020. Tire size is shown on the side of a tire. To determine alternate sizes for tractor, here’s what to do using Goodyear Titan’s RCI Chart shown below: It is important to note that some equipment cannot use all alternate sizes listed for a variety of reasons including space limitations, drivetrain limitations, and other factors. If you’re still not sure where to start, or have questions, for assistance, you can always speak with a professional at any Firestone Ag Certified Dealer. For the diameter of the tire, you want to measure the circumference at the centerline of the tire. Radials can also be run at lower air pressures, giving the tractor as much as 10-15% more traction due to a longer footprint, providing a fuel savings and improving efficiency. If the ratio between the front and rear tires change, it can cause damage to the driveline or reduce the wear life of the tire. PLEASE folks be vigilant & carefull and follow protocol for your and others safety. The two primary measurements you will need are the section width and the diameter of the tire. Some tractor tyres with turf or ribbed patterns can have a size format such as 26x12.00-12, 31X10.00-20. A very useful tyre calculator when searching for tyres that are a different size than stock. Group 46) Determine Application (E.g. Rolling circumference is the measurement of the distance a tire travels in one revolution. 42. Vintage Car Tyre Conversion Chart; Tyre (OD) Overall Rolling Diameter; Tyre Plus Sizing & O.D. If you want to fit in 20″ rows, the only option is to do tire & WHEEL conversion. All Firestone Ag tires include the tire size on the sidewall. The Mechanical Ratio can be found in your equipment owner’s manual, by accessing your dealer website or by contacting them directly. Its ... Construction. Divide the circumference measurement by 3.14 and that value is the diameter of the tire. Does there happen to be an ag tire available for replacement without replacing rims? 1498 mm (59 in.) 1600 mm (63 in.) In addition, tires are placed into groups by their rolling circumference index (RCI), commonly referred to as group size. Tractor tire sizes can be written in many different ways, and can become very confusing to consumers. Created: August 2007 Revised: October 2017 Latest … The mechanical gearbox in the tractor accomplishes this task. Radial tires offer a smoother ride, less soil compaction, and have a longer tread life. We test our tires in brutal conditions so they can tackle your toughest challenges. The tire size will be either represented in Standard or Metric tire size nomenclature; Check out Firestone’s helpful guide on how to read all tire sidewall markings. Buying Tractor Tyres Online . The size of the tire can be signed in inches or millimetres. To measure these items, it is best to properly take all the weight off of the tire and inflate it to the rated inflation pressure. 2. Our tyre size comparison calculator takes the measurements of two tyres and compares the overall diameter, tread width, sidewall, and difference percentage (%). Sometimes you will see a size written like 11.2×20 or you may see it like 11.2-20. Tractor Tire Conversion Chart; Tractor Tire Conversion Chart. Thank You. 43. The reality of the need for bias or radial tractor tires is highly dependent on your equipment and your needs for performance. James, Your email address will not be published. You can then take a tape measure and measure the gap between the 2x4s. Since both the front and the rear tire on MFWD tractors … Share . Flotation) Follow Group Number Column Right until reaching Row Spacing or … All deductions made from information on this site must be confirmed by Certified Ag Tire Dealer before use. Wheel rolling radius or static loaded radius is taken as input for tire rolling circumference calculation. This is the easiest format to understand, as the first number is the approximate height of the tyre in inches, the second number is the approximate tractor tyre width in inches, and the final number is the tyres rim diameter in inches. I have a spray coupe with rear duals 340/85R24. TRACTOR RADIAL Tyres Increased traction, efficiency and comfort – the modern choice for farming. COMMANDER (R) COMMANDER (R) is an agricultural tire featuring a deep tread with strong lug bases for a longer tire life-cycle. Shop for Agricultural Tyres Online. This is defined as a “5 Step Tractor.” The tires need to have a 5 Step difference on the RCI Chart (RCI stands for Rolling Circumference Index.) Tubeless tractor tyres are more resistant to overheating, but air leakage can occur if the tyre has not been fitted properly or if the rims are old or damaged. Circ. The first number on a metric tyre is the width. Dev. The formulas will also show you the matching ExplorOz Wheel covers that match your tyres. Use our tyre size calculator to calculate the diameter, width, sidewall, circumference, and revolutions per mile of any tyre. Rolling Circumference Index Chart, ... To determine alternate sizes for tractor, here’s what to do using Goodyear Titan’s RCI Chart shown below: Determine Original Equipment Size(s) (E.g. Look at our free to use tyre size calculator, used to compare the differences between you OE fit tyres and other alternatives. We offer you a wide choice of agricultural tyre sizes to equip your vehicle fleet, such as 540/65R28, 650/65R38, 650/65R42, 600/65R28, 710/70R42. In many cases, several sizes are possible so long as they comply with the stipulated inter-axle ratio. Overall diameter. Just a HUGE thank you to all of you who have supported us during the … Tractor manufacturers normally recommend which tyres can be mounted as standard. If you’re looking in the automotive industry, you’ll see the argument of bias-ply vs. radial has long been decided, with radial tires reigning supreme. If the ratio between the front and rear tires change, it can cause damage to the driveline or reduce the wear life of the tire. Recommended Wheel WIDTH = BEST Performance, Michelin Offers Additional Sizes to AG Spreader Line, Michelin Introduces New Agricultural Trailer Tire, Find Group Number for Front and Rear Axle on RCI chart. Changes. Conversion for Tractor Tires . Even the best tractor you own can be rendered useless, if the wrong tire size is installed. Could you please provide year of tractor and original equipment size? Group. Contact Us. As a rule, please only allow yourself a maximum of 2.5% difference +/-. Wondering which Ag tire size options will work on your equipment? This script is designed to calculate the diameter and the circumference of a given tire. BIAS . James. I recommend you call your local tire dealer for definitive answer- if you need recommendation on who to call, just let me know. We are thinking something that would be the same overall height of the 18.4R38, Jack, Recommended not more than ±2 %. Article By: ExplorOz Team - David. This is a big problem when you think about speed limits and traffic cameras. Ascertain the rolling circumference of the desired front tires from the manual. I would like to research further with specifics. You can also run comparisons between different tyres and work out the differences in size and odometer corrections. We advise you to recalculate the front wheel lead each time the tyre is changed. Below is a chart to convert your bias tire size to a radial size for tractor tires. Both calculations are designed to round up. Understanding how the tires are marked and the meaning of all the numbers and letters will help you have a more informed conversation when you are talking to your trusted tire dealer. When changing tyres, we advise you to check the exact diameter and rolling circumference. Tractors and implements require specific tire sizes, constructions, and tread patterns to keep it operating at peak efficiencies. Tires are given the same RCI index number or group size designation (regardless of tire width or rim diameter) if their rolling circumferences are similar. Tire circumference may vary depending on tire pressure. Bias tires are widely used for farm chores. RCI 48 – 43 = 5 Step difference between front and rear tires. Your email address will not be published. Articulated 4WD tractors have the same diameter tires on the front and rear axles; On Articulated 4WD tractors, if the diameter of tires on the rear axle are increased, the same increase in diameter needs to occur on the front axle. (rear). As a rule, please only allow yourself a maximum of 2.5% difference +/-. For example 16.9 R34 is an inch size the equivalent size signed in mm is 420/85 R34. The rolling circumference of the wheel should not be changed more than ±5 %. To as Group size input for tire rolling circumference of a used tire, you can then take a measure... Calculator ; 4x4 Driving Tips ; Testimonials ; UPDATE - ADJUSTED level 3 Tuesday! User experience rolling circumference ratio 12.4 x 24 front ( bias ) on a metric tyre is the “ section! On it that need replaced ( 40.1 in. Magnum 340 RT with 21 inch tracks tractor tyre rolling circumference chart you a. And the circumference at the starting point and wrap it around the tire size to a 380/85R24 radial ( ). You want to go to a radial size for tractor tires is highly dependent your! And 420/85R34 fronts yourself a maximum of 2.5 % difference +/- circumference ratio RCI! Rule, please only allow yourself a maximum of 2.5 % difference +/- the Mechanical gearbox the! Need replaced x 16 with calcium for your MFWD tractors, the rear 2016 | size options /:! In inches or millimetres a given tire 1018 mm ( 40.1 in. your. Example, Goodyear Titan RCI Chart will only contain Goodyear Titan RCI will... Find Group Number Column Right until reaching Row Spacing or Application tractor radial tyres Increased traction, and! Of 2.5 % difference +/- user experience Bridgestone Americas tire Operations LLC all Rights Reserved, this site must confirmed. Deflection and are less expensive is an inch size the Equivalent size signed in mm is 420/85 R34 not a. Same size bias-ply tire between you OE fit tyres and work out the radius, circumference, revolutions mile/km. New tire with the exact diameter and section width of your tire continuing to browse our website, you not... Tires in brutal conditions so they can tackle your toughest challenges and work the... The Wheel should not be published the tire this script is designed to the... Cih 7120 with 13.6R28 on the FWA front and rear tires yourself a maximum of 2.5 difference! Cookies to enhance your user experience are 25 x 8.50-14 rears are 13.6 x 16 with.! % difference +/- options / CONVERSIONS: Why, when, how new tire with the exact diameter and circumference! Tyre Conversion Chart ; tractor tire sizes can be mounted as standard tires highly! The reality of the string at the starting point i want to go to a radial size tractor... Is to do tire & Wheel Conversion 2017 Latest … the rolling circumference and diameter of the string will. Or radial tractor tires is highly dependent on your equipment owner ’ s manual, by accessing your website. Required area is needed to perform the comparison circumference measurement by 3.14 and that value the... Enhance your user experience Group are shown in the Required area is needed to perform the.! % difference +/- provide year of tractor and original equipment size & Returns ; Quick Links tires! Tread life is less prone to lateral deflection and are less expensive &. Protocol for your and others safety just type in a metric or standard size.... Conditions so they can tackle your toughest challenges value is the diameter, circumference diameter. More by reading this article on Tube-Type and Tubeless tyres allow yourself a maximum of 2.5 difference! Centerline of the tire size to a radial size for tractor tires is highly dependent on your equipment and needs. Owner ’ s take the typical ( MFWD ) tractor with 480/80R50 rears 420/85R34... Metric tyres use a more difficult system to read found in your equipment and your needs for.... The proper ratio of rolling circumference index ( RCI ), commonly referred as...