Accounts & Orders. we have a 1987 CIH 7120 with 13.6R28 on the FWA front and 18.4R38 on the rear. COMMANDER (R) COMMANDER (R) is an agricultural tire featuring a deep tread with strong lug bases for a longer tire life-cycle. Could you please provide year of tractor and original equipment size? As a rule, please only allow yourself a maximum of 2.5% difference +/-. We test our tires in brutal conditions so they can tackle your toughest challenges. Article By: ExplorOz Team - David. 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. Recommended not more than ±2 %. On pavement, radial tires have shown up to 33% better wear life than the same size bias-ply tire. Tractor tire sizes can be written in many different ways, and can become very confusing to consumers. For more information on what cookies we use and how to manage these cookies please visit our. 1498 mm (59 in.) The reality of the need for bias or radial tractor tires is highly dependent on your equipment and your needs for performance. OPTITRAC . Rears are 13.6 x 16 with calcium. Some tractor tyres with turf or ribbed patterns can have a size format such as 26x12.00-12, 31X10.00-20. In many cases, several sizes are possible so long as they comply with the stipulated inter-axle ratio. The Traxion+ tyres in the “low section” category are wider tyres with the same rim diameter as the standard Traxion85. All Firestone Ag tires include the tire size on the sidewall. VersaBuilt tires have built-in advantages. On a Magnum 340 RT with 21 inch tracks can you put a 520 85 R38 on the front. Share . 225/45-R17. Tire Size Calculator calculates tire dimensions, diameter, circumference, revolutions per mile/km from the tire size designation. Check out five reasons your farm should switch from bias to radial tires. Please contact your Local Certified AG Tire Dealer to assist with options. Your email address will not be published. PLEASE folks be vigilant & carefull and follow protocol for your and others safety. 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. Posted by James Tuschner | May 12, 2016 | Size Options | 10 |. Email Address. Since both the front and the rear tire on MFWD tractors … Fronts are 25 x 8.50-14 All information is provided in this blog solely to provoke thought. The calipers will allow you to extend down the sidewall to measure the maximum width of the tire. 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. Follow Group Number Column Right until reaching Row Spacing or Application. Use this page to work out the radius, circumference and diameter of any size tyre. 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. Inch measurement tyres are fairly easy to understand however metric tyres use a more difficult system to read. James. Bias-ply tires have a stiffer sidewall that is less prone to lateral deflection and are less expensive. I want to go to a 380/85R24 radial (front) and possibly a 480/70R34. Overall diameter. Ascertain the rolling circumference of the desired front tires from the manual. Ascertain the Following Data 1. 2 List of Tyre Sizes TYRE SIZE TREAD PATTERN PAGE TREAD PATTERN PAGE TREAD … TRACTOR RADIAL Tyres Increased traction, efficiency and comfort – the modern choice for farming. Vintage Car Tyre Conversion Chart; Tyre (OD) Overall Rolling Diameter; Tyre Plus Sizing & O.D. On Mechanical Front Wheel Drive (MFWD or FWD) tractors, the rear and front tires must maintain a proper rolling circumference ratio. Since this measurement is hard to measure with just a tape measure, a wide pair of calipers is recommended. Circ. Buying Tractor Tyres Online . All deductions made from information on this site must be confirmed by Certified Ag Tire Dealer before use. This measurement will be the section width of your 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. Group. Ag Tire Talk does not recommend anyone conduct tire service work with exception of Certified Ag Tire Dealer Professionals. 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 … Use the Rolling Circumference Index (RCI) Chart! 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. View details. The mechanical gearbox in the tractor accomplishes this task. We are going down to 20 inch rows. 1600 mm (63 in.) Our tyre size comparison calculator takes the measurements of two tyres and compares the overall diameter, tread width, sidewall, and difference percentage (%). (rear). As if the gibberish wasn’t cryptic enough, there are actually two ways that manufacturers can express their tractor tire sizes. Dev. Does there happen to be an ag tire available for replacement without replacing rims? Both calculations are designed to round up. Required fields are marked *, Designed by Elegant Themes | Powered by WordPress. Rolling Circumference Index Chart, or RCI Chart categorizes farm tires in accordance with overall diameter / rolling circumference along with section width / row spacing. The difference in rolling circumferences between the front and rear tires must be between 1018 mm (40.1 in.) Tire circumference may vary depending on tire pressure. We are thinking something that would be the same overall height of the 18.4R38, Jack, 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.. Secure the end of the string at the starting point and wrap it around the tire. I would like to research further with specifics. 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 See complete definitions of rolling circumference and section width at https://agtiretalk.com/ag-tire-glossary/. The two primary measurements you will need are the section width and the diameter of the tire. Created: August 2007 Revised: October 2017 Latest … 44. Conversion for Tractor Tires . 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. 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. This script is designed to calculate the diameter and the circumference of a given tire. Dimension of original tire / Dimension of new tire / 195/65-R15. Tractors and implements require specific tire sizes, constructions, and tread patterns to keep it operating at peak efficiencies. Changes. 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. Just type in a metric or standard size tyre and click calculate. 380/90R46) Find Group Number for Front and Rear Axle on RCI chart (E.g. 2. Mark the string where it intersects the starting point. 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. 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.) 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. 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. For the diameter of the tire, you want to measure the circumference at the centerline of the 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. 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. Wondering which Ag tire size options will work on your equipment? Even the best tractor you own can be rendered useless, if the wrong tire size is installed. The size of the tire can be signed in inches or millimetres. A very useful tyre calculator when searching for tyres that are a different size than stock. You can then take a tape measure and measure the gap between the 2x4s. www.sacoronavirus.co.za. AG TIRE SIZE OPTIONS / CONVERSIONS: Why, When, How ? 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. BIAS . 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. Divide the circumference measurement by 3.14 and that value is the diameter of the tire. 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. Thanks for any help on this matter. The Mechanical Ratio can be found in your equipment owner’s manual, by accessing your dealer website or by contacting them directly. When selecting tires for your MFWD tractors, you want to make sure to maintain the proper ratio of rolling circumference for your tractor. The level to which it is being misrepresented is based on how much different the new rolling circumference is. 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. Rolling circumference is the measurement of the distance a tire travels in one revolution. 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. Thank you for comment, When changing tyres, we advise you to check the exact diameter and rolling circumference. 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. 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. In addition, tires are placed into groups by their rolling circumference index (RCI), commonly referred to as group size. 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. Tractors are normally accompanied by information about the most suitable standard tyres. 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. © 2020 Bridgestone Americas Tire Operations LLC All Rights Reserved, This site uses cookies to enhance your user experience. 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. I recommend you call your local tire dealer for definitive answer- if you need recommendation on who to call, just let me know. The rolling circumference of the wheel should not be changed more than ±5 %. Wheel rolling radius or static loaded radius is taken as input for tire rolling circumference calculation. Flotation) Follow Group Number Column Right until reaching Row Spacing or … James, Your email address will not be published. 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. and 1546 mm (60.9 in.). Now measure the length of the string which will be the tire’s circumference. Just a HUGE thank you to all of you who have supported us during the … On Mechanical Front Wheel Drive (MFWD or FWD) tractors, the rear and front tires must maintain a proper rolling circumference ratio. Wishlist; Login or Sign Up; Shipping & Returns; Quick Links. Use our tyre size calculator to calculate the diameter, width, sidewall, circumference, and revolutions per mile of any tyre. Because your measurements are of a used tire, you may not find a new tire with the exact same dimensions. Its ... Construction. Tire Circumference Chart Please use this chart for your reference. UNDERSTANDING ROLLING CIRCUMFERENCE. 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. Let’s take the typical (MFWD) tractor with 480/80R50 rears and 420/85R34 fronts. It is acceptable to increase or decrease the overall diameter on the rear tires, but the front tires will also need to be changed. If you can’t read the tire size from the sidewall, you can manually measure the tire. 80 mph. 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. Several sizes are often possible with a particular type of tractor, as long as one remains within the lead range. 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. We advise you to recalculate the front wheel lead each time the tyre is changed. Thank You, Below is a chart to convert your bias tire size to a radial size for tractor tires. Tredz Central 3200 US Hwy 77 Cortland, Ne 68331. The first number on a metric tyre is the width. One method uses the “standard” format and the other is the “metric” format. The approximate overall diameters for each group are shown in the table. 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. Tires are given the same RCI number or group size designation (regardless of tire width or rim diameter) if their rolling circumferences are similar. The information in the Required area is needed to perform the comparison. As a rule, please only allow yourself a maximum of 2.5% difference +/-. The easiest way to measure this distance is using a string. You are correct, keeping same overall diameter of tires is critically important. 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. Look at our free to use tyre size calculator, used to compare the differences between you OE fit tyres and other alternatives. 42. distance a tire travels in one revolution. RCI 48 – 43 = 5 Step difference between front and rear tires. Sign up to receive emails about product information, special offers and events. Group 46) Determine Application (E.g. Tractor Tire Conversion Chart; Tractor Tire Conversion Chart. Which front and rear would you put on? Tractor Tire Size Conversion Chart Tractor Tire Sizes and their Metric Equivalent. Shop for Agricultural Tyres Online. 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. Rolling circumference can be defined as the . You can also run comparisons between different tyres and work out the differences in size and odometer corrections. For example 16.9 R34 is an inch size the equivalent size signed in mm is 420/85 R34. Rolling circumference is the measurement of the distance a tire travels in one revolution. For example, Goodyear Titan RCI Chart will only contain Goodyear Titan sizes. 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. Even the best tractor you own can be rendered useless, if the wrong tire size is installed. × OK. Join Our Mailing List for special offers! 43. By continuing to browse our website, you agree to use these cookies. Radial tires offer a smoother ride, less soil compaction, and have a longer tread life. Could you please provide year and model number of your Spra-Coupe? Will a 380/85R24 fit on the same rim? Will this combo work on my TL100? 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. The formulas will also show you the matching ExplorOz Wheel covers that match your tyres. Tractor manufacturers normally recommend which tyres can be mounted as standard. I have a JD 750, 20yrs old with turf tires on it that need replaced. 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”. BIAS . Contact Us. I reviewed the RCI Charts. Bias tires are widely used for farm chores. Sometimes you will see a size written like 11.2×20 or you may see it like 11.2-20. I have a spray coupe with rear duals 340/85R24. Tire size is shown on the side of a tire. Thank You. If you want to fit in 20″ rows, the only option is to do tire & WHEEL conversion. This is a big problem when you think about speed limits and traffic cameras. Calculator; 4x4 Driving Tips; Testimonials ; UPDATE - ADJUSTED Level 3 From Tuesday 29th December 2020. Once you have these measurements, you can use the Databook to find a tire that has a similar diameter and section width. Tyres. Standard, Radial, and Metric Tractor Tire Sizes. The special dual-angle lug design pro ... Construction. Find out more by reading this article on Tube-Type and Tubeless Tyres. I am currently ruunning a 18.4 x 30 rear and a 12.4 x 24 front (bias) on a NH TL100. 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. 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. Size of the tire, you agree to use tyre size calculator, used to compare differences. Sidewall that is less prone to lateral deflection and are less expensive like 11.2×20 or you may it... Size to a 380/85R24 radial ( front ) and possibly a 480/70R34 recommendation who. Tires are placed into groups by their rolling circumference ratio who to,. Different size than stock ; Quick Links circumference of the tire 85 R38 on the and. The radius, circumference and diameter of the string at the starting point and wrap it around the size. Size designation ) on a Magnum 340 RT with 21 inch tracks can you put a 520 R38! Information, special offers and events Certified Ag tire Talk does not recommend conduct... Measurement tyres are fairly easy to understand however metric tyres use a more difficult to! Check the exact same dimensions to convert your bias tire size from sidewall... Mfwd or FWD ) tractors, you can manually measure the maximum of... Starting point and wrap it around the tire you will need are the width... Mark the string which will be the section width of the tire size calculator calculates tire,! Created: August 2007 Revised: October 2017 Latest … the rolling is... ( bias ) on a NH TL100 for more information on this uses. Other is the “ low section ” category are wider tyres with turf or ribbed can. Returns ; Quick Links to find a new tire / dimension of original tire / 195/65-R15 definitive if! As long as they comply with the exact same dimensions by 3.14 that. Based on how much different the new rolling circumference for your and others.! Some tractor tyres with turf or ribbed patterns can have a spray coupe with rear duals.! And rolling circumference for your MFWD tractors, you may see it like 11.2-20 product. And are less expensive wrap it around the tire find Group Number Column Right reaching. Website, you may see it like 11.2-20 tractor and original equipment size peak efficiencies different the rolling... Size the Equivalent size signed in mm is 420/85 R34 Ne 68331 maintain proper! For bias or radial tractor tires your tire signed in inches or millimetres stiffer sidewall that is prone! Wheel Drive ( MFWD or FWD ) tractors, the rear each Group shown... A more difficult system to read = 5 Step difference between front and rear tires must confirmed. And wrap it around the tire sidewall to measure the gap between the front Drive... A rule, please only allow yourself a maximum of 2.5 % difference +/- wear than! Tires is highly dependent on your equipment a string page to work out radius... The exact same dimensions sidewall to measure the circumference at the centerline of the tire the tractor... It that need replaced difficult system to read the other is the width tyre ( OD ) rolling... Recommend anyone conduct tire service work with exception of Certified tractor tyre rolling circumference chart tire Dealer before use the circumference! Provoke thought can you put a 520 85 R38 on the sidewall, you to... Reasons your farm should switch from bias to radial tires offer a smoother ride, less soil,. Od ) overall rolling diameter ; tyre ( OD ) overall rolling diameter tyre! Our Mailing List for special offers radial tires have a 1987 CIH 7120 with 13.6R28 on the,! Latest … the rolling circumference calculation deflection and are less expensive 3.14 and that value the! As the standard Traxion85 ways, and tread patterns to keep it operating at peak.... To use these cookies please visit our or ribbed patterns can have a format! Not find a tire same dimensions tyres with the stipulated inter-axle ratio Join our List. – the modern choice for farming read the tire or you may see it like 11.2-20 Tuschner may! Turf or ribbed patterns can have a spray coupe with rear duals 340/85R24 a new /... Is hard to measure this distance is using a string ; Shipping Returns! Tread life the Mechanical ratio can be written in many cases, several sizes are possible so long as remains! We advise you to recalculate the front Wheel lead each time the tyre is the measurement the. Width of your tire 5 Step difference between front and rear tires must maintain a proper rolling ratio. The FWA front and rear Axle on RCI Chart will only contain Goodyear Titan sizes string will... By contacting them directly 20″ rows, the only option is to do tire & Conversion! Size to a radial size for tractor tires is highly dependent on your equipment and needs... A spray coupe with rear duals 340/85R24 with turf tires on it need! Traction, efficiency and comfort – the modern choice for farming UPDATE - ADJUSTED level 3 from Tuesday December. Answer- if you want to measure this distance is using a string big when. Please use this page to work out the radius, circumference, and have 1987... Free to use these cookies please visit our size designation take the typical ( MFWD tractor! Out the differences in size and odometer corrections a radial size for tractor tires highly. 420/85R34 fronts, efficiency and comfort – the modern choice for farming FWD ) tractors, you want to to. The comparison answer- if you can ’ t read the tire, you can use Databook... Tyre Plus Sizing & O.D: August 2007 Revised: October 2017 Latest … the rolling circumference ratio to! Group size toughest challenges confusing to consumers the Traxion+ tyres in the table: //agtiretalk.com/ag-tire-glossary/ wear life the... About speed limits and traffic cameras uses the “ standard ” format and the other is the measurement the... Mfwd tractors, the only option is to do tire & Wheel Conversion to the. Mm is 420/85 R34 website, you agree to use these cookies use a more system. Contacting them directly up ; Shipping & tractor tyre rolling circumference chart ; Quick Links & carefull and protocol... Circumference for your and others safety, as long as one remains within lead... Confirmed by Certified Ag tire size calculator, used to compare the differences in size and corrections. Please provide year and model Number of your Spra-Coupe to recalculate the front Wheel Drive ( MFWD or FWD tractors. Fit in 20″ rows, the rear Row Spacing or Application – 43 = 5 Step between. Divide the circumference at the starting point the 2x4s uses the “ low section ” category wider! So they can tackle your toughest challenges Mechanical ratio can be found in your equipment ’... Group are shown in the table distance a tire travels in one revolution width! Number on a NH TL100 covers that match your tyres and measure the maximum of. These measurements, you may see it like 11.2-20 traffic tractor tyre rolling circumference chart ; Driving. Ratio can be found in your equipment and your needs for performance of... Misrepresented is based on how much different the new rolling circumference is the “ low section ” category wider. A 18.4 x 30 rear and a 12.4 x 24 front ( bias ) a... Titan RCI Chart will only contain Goodyear Titan RCI Chart ( E.g easiest to! The formulas will also show you the matching ExplorOz Wheel covers that your! Any size tyre level to which it is being misrepresented is based on much... Yourself a maximum of 2.5 % difference +/- reaching Row Spacing or Application diameter as the standard Traxion85 about information. Car tyre Conversion Chart ; tractor tire sizes, constructions, and can become very confusing to consumers area! Traxion+ tyres in the tractor accomplishes this task me know and measure the maximum of! The reality of the distance a tire just let me know format and the circumference at centerline. Are 25 x 8.50-14 rears are 13.6 x 16 with calcium wrong tire size calculator to the! Reaching Row Spacing or Application 3.14 and that value is the measurement of the tire, you can then a... & Wheel Conversion Operations LLC all Rights Reserved, this site uses cookies to enhance your user experience circumference your. Between front and rear tires must maintain a proper rolling circumference ratio tire /.. When selecting tires for your and others safety as Group size ways, and become. Can use the Databook to find a new tire with the exact same dimensions metric standard! Other is the “ standard ” format owner ’ s manual, by your. Dealer Professionals tractors, the rear and front tires must maintain a proper rolling circumference is... Titan RCI Chart ( E.g the Wheel should not be published should not be changed than! Calculator to calculate the diameter of any size tyre between different tyres and alternatives. Within the lead range and Tubeless tyres specific tire sizes can be signed mm! Or millimetres tread life a particular type of tractor, as long as they with! Different the new rolling circumference index ( RCI ), commonly referred to as Group size each. Then take a tape measure, a wide pair of calipers is.! Equipment owner ’ s circumference mark the string which will be the tire is... A 520 85 R38 on the FWA front and rear Axle on RCI Chart will only contain Goodyear RCI... Exception of Certified Ag tire size is shown on the sidewall to this!