Search Plus, the 6x12 enclosed trailer comes with a 5 year Manufacturer's Limited Warranty! EXAMPLE 1: The water tanks are placed on the trailer one one on each side of the axle as far away from the axle as possible. Because Torsion Axles donât have springs to mount, itâs the bracket width (usually meaning the outside dimension of the frame members or Frame Width ) that defines itâs Mounting Position. Would the second case be likely to tow stably, despite being outside the normal rule of thumb? I am including a good picture of the measurements that are required on a tandem axle and a chart that will list the hangar distances on a 2,000-lb axle and a 3,500-lb axle. Payload Capacity 5200 lb. I don’t think there is any magic claimed in the angle used per se. In some cases it makes the tongue load below 10% which borders on dangerous. Another thought — for a tiny house that won’t move almost ever, the exact axle position is of less importance because that is mostly for dynamic (towing) stability. “? There once was a boy who came to his mother and asked “How do rockets get to the moon?” She replied “Ask your dad.” To this, the boy mumbled “I don’t want to know that much about it.”. If there is not enough tongue weight, a change like a bump or turn or steering correction leaves the trailer mass pivoting, and it takes additional energy to get things back to stable. hello MR. mechanic , i have a trucks and trailers spare parts shop and i wanted to know the main component of the trailer so i can have a basic idea if you can , Graciano Diosdado May 24, 2020 @ In straight line action handling won’t be much different, but in dynamics, Example 2 will “feel” heavier because of the inertia moving the load in teeter-totter, and turning. When determining the axle placement on a trailer, an important factor to consider is the tongue weight. They will get you close, but if you have something specific you’re trying to haul, I’d do the calculations and know for sure. When checking for ‘The Pivot Point’, owing to the fact that the wheels and axles are ‘supportive’ weight, and not ‘load’ weight, should they be on or off the trailer, when finding the ‘Pivot Point’? Treat them as a single axle. Here’s the whole answer, from The Mechanic. 4:53 PM. For tandem axles or triple axles, use the center of the axle ⦠This 12-foot trailerâs features include a durable, clean looking gator-tuff powder coat finish, a 7000-pound gross vehicle weight rating, and a heavy-duty designed frame. Leading me further down that thought experiment was helpful. As a thought experiment to illustrate my question, let’s imagine an 8′ utility trailer with an axle set a little back from the centre of the bed, with a tongue length of 4′, loaded evenly, with a result of 15% of the weight being on the tongue at the coupler. Axles are rated at various capacities from 1,000 to 10,000 pounds. Are you ever scared by what you see in tow rolling along? Trying to figure out location for axles. When building your own trailer, run the calculations a few times with different load scenarios, then design for the maximums. Calculate the center point of the two axles by multiplying the trailer's length by 0.6. Thatâs the answer to the customer question above. To be honest I’m not mathematically adept, therefore all this theory is kinda wasted on me and although I usually like things perfect, working this out takes a better mind than I have, therefore I am looking for that ‘quick fix’! Weight of the Toolbox: WT = 300 Lbs @ L1 = 30″ Length of the Tongue: L2 = 42″ Trailer Bed Length: L3 = 96″ Trailer Frame Weight: WF = 450 Lbs @ L4 = 83″ Distributed Load: WD = 2250 Lbs, Center @ L5 = 90″. 3:03 PM. ... from a trailer because of the weight on the rear of fire box is heavy. However, for existing trailers (if you want to check the axle position or maybe move the axles), please read this follow-on article also about Calculating Axle Position.). 2) The axles (via the wheels and tires) are already on the ground, so their weight can be ignored. My experience says when calculating axle position for a loaded trailer, the axle(s) weight will only make a small difference for placement, and it biases the CG back just a little which is good for stability. From the example above, if we remove the toolbox, the calculated axle position changes to 100.9″ Or, using the example, if WT is 15% (instead of 12%), the axle position becomes 97.6″. Utility Trailer Technical Information: * The 6 x 12 utility trailer plans give a deck size 2 inches wider than 6 ft. and 3.5 inches longer than 12 ft. (This allows a true 6 ft load width, and true 12 ft load length clearance.) The 60/40 axle placement formula is a great starting point and does take into account the tongue of the trailer from where the trailer sits on the hitch ball. I’ll be towing camping gear. However, some 12-foot enclosed trailers only have a gross vehicle weight rating of 3,000 pounds. Great article on axle loading. Let’s make a collection of photos here just for a few good laughs — Scary trailers on the road. It improves towing stability, maneuverability, and safety. So, how do you know proper trailer axle position? I’m currently building a twin axle utility trailer 10′ by 5′. I’m trying to give enough of the theoretical for understanding, but focus primarily on the practical because that’s what really matters in the end. Drive onto the scale such that just the trailer wheels are on the scale. The picture is from the product page of the Tandem-Axle Trailer Hanger Kit for Double-Eye Springs, part # APT1 . This is where to start with when picking out axle locations for a tandem axle trailer. I am a big fan of this website. 5:46 AM. Re-connect and drive the tow vehicle wheels off the scale so that only the trailer axles are on the scale and get a ticket with the trailerâs axle weight listed. My point being , have a good long draw bar, just enough weight on the ball to prevent bucking and ease of handling when empty, draw bar weight has little to do with handling, it is more the distance from the load centre to the tongue centre verses road speed. Adding 6′ plus the goose neck will almost certainly require bigger main beams. Steve Arnall October 18, 2019 @ If you think about balancing on a teeter-totter, the balance point does not include the stand that the teeter-totter is mounted on — but, when you pick up the teeter-totter to move it some place else, you also have to pick up and carry the stand it mounts on. When towed minus the sprint car it tended to make the tow car over steer, when balanced with spint car on board it towed like a dream. My Opinion? It’s entirely up to you. Save my name, email, and website in this browser for the next time I comment. Thatâs the answer to the customer question above. If I push to 200kg nose weight and 10% bias then I can only tow 2000kg. Thanks for writing again. 9:20 AM, General rule for a gooseneck trailer is 70% back from the front of the trailer, as far as doing these calculations unless you are putting the same thing in the trailer in the same locations I don’t see where it would help. You are going to have to get the trailer off the ground and onto jack stands with or without the boat on it. (150kg is the weight of 2 people! The Mechanic September 9, 2019 @ Come on over to http://utilitytrailerplans.net/ for a couple free sets of utility trailer plans/blueprints. Nothing. (Let’s also ignore the other inherent stability benefits offered by the longer tongue, for the sake of this thought experiment. Measure the total length of the box(A) and divide that dimension by 2 to find the centerline of the trailer box. If the tongue weight is exactly the same in both examples, how will the trailer handle in both examples. Multiply this length by .4. Or is that the problem? The Mechanic January 20, 2020 @ At some point it’s better to start with a platform that comes closer to your end goals instead of chopping so much. Firstly, you say the wheels and axles are part of the ‘supportive’ weight, so their weight can be ignored. NOTE: The images show a single axle trailer. A long tongue has other nifty advantages too — within reason — though your 12′ tongue will create other issues. 10:43 PM, Hi I have a question, I got 60’ frame it was from amobile home three axels were in the frame I cut 20 feet to the back of the frame cuz I want To make a Tinay home on it, my question is now I need to move the axels since they were place for a 60 feet frame now its only 40 feet frame how can I calculate to where to move the axels now? I have a 16ft car trailer I want to extend 6ft to add sleeping quarters and convert to goose neck. If you have more point loads, just add them in as illustrated. Don’t you hate it when the answer starts with “It depends . So, in this example, simply mount the axle so that the axle center point is four feet from the rear of the trailer. There’s much more to tongue length. Gooseneck, bumper pull, or pintle-eye in various axle configurations. That is on the margin, but can work. 10:36 AM. Or, if we take the toolbox off and went to 15% tongue weight, the desired trailer axle position is 65% of the bed. 8:33 AM. Even if it was normally stable, if something happens for the trailer to move unexpectedly (flat tire, gust of wind, large hole in the road, etc. Trailer length, including the tongue, is 198 inches or so depending on options. Good luck. We have 2 articles that cover positioning of the axle. 5:52 AM. Ok..maybee this was discussed in previous comments but I am new here and I feel my issue is unique…I have a tilt body trailer with a cargo area of 5×10..when trailer is empty it would sway almost out of control..I would drive my golf cart on (forward) and it would still sway..I back it on and no sway. These examples show that the 60% guess-of-thumb is not always best. This method should only be used if you will be hauling evenly distributed loads.Â. approx. Where to Position the Trailer Axle? Interesting question. Deck over wheels, for maximum load surface and strength. Setting the axle at 60% is the lazy way. Improper placement of a trailer axle reduces load capacity, towability and safety. How can it be stated that 3500kg can be towed with 150kg nose weight? 6:57 PM. Subscribe to get special offers, free giveaways, and once-in-a-lifetime deals. ), the tow vehicle can be tossed. ), For rear connecting trailers (traditional), weight of the tongue should be in the 10% – 15% range of total trailer weight. Back axle is at 46” from back and front axle at 78.5” from back. This balance is important to maintain the correct downward force at the tongue. I figured load c.o.g. Utility Trailer 6 ft 10 inch x 12 ft Tandem Axle 7k GVWR. Mechanic January 19, 2020 @ and place the load just forward of centre of the axle group, it’s just a trailer, KISS. Single-Axle Trailers with 3500-lb. So, the Center of Mass is not the Geometric center, nor is it the center of the trailer bed. So making the tongue (your 12′ experiment) long does work like you say, and actually it makes the bump feel (to the trailer load) like it’s half as high. Calculations prior to completing a trailer are a little nebulous (“hit & miss”?) Also written 3000#. So, our Axle position is 94.3″ from the hitch. That axle centerline is where you will attach the middle spring hanger. You are on the right page, or for a different perspective of the same thing, try Calculating Axle Position. It is extremely helpful. Roads are brutal, and momentary loading is much higher, so best not to tempt fate. Thanks. I used to build trailers and there is no set tongue length, it depends on the entire length of the trailer and how far you want to be able to cut it, as far as the axle placement, I always found the center of the trailer and move back one inch for every foot of the trailer, this keep it ⦠This can be confusing, I know. The Center of Mass is where the hammer will balance — say on your finger. Hopefully I’ll do a better job answering this time. The most integral parts of your boat trailers running gear would be the boat trailer axle, and the trailer hubs. You want the tongue weight of the trailer to be approximately 10 percent of the gross trailer weight. That back and forth switching causes some weird dynamics for the driver and he feels like it is “bucking”. Utility Trailers. Brilliant, thanks! The resulting number is the distance from the rear of the cargo box to the center of the axle. Patrick Watts October 31, 2020 @ 18ft trailer centerline of box =9ft center line of axles= 9ft+ one inch for every foot of trailer or 18 inches= 10" 6" axle placement @ 60/40= 10' 8" axle centerline Not a lot of difference, placing the axles 2 inchs further back will only slightly increase tongue weight and raise the rear of the ground a minimum amount for clearance issues. All but one had no more weight on the draw bar than i could lift, for two very good reasons, excessive draw bar weight destroys the jockey wheel over time and renders the trailer almost impossible to manoeuver single handed and buries the jockey wheel in your just laid lawn. Small changes do make a difference, but I don’t personally have any experience with a 36 degree tongue. 8:38 PM. Starting from the front of the cargo box, measure back the distance determined in step two. © 2021 trailerplans I’ve been crunching the numbers for empty vs loaded and wanted to make sure if the 600 lb for axles should be included. I’m getting a full load of firewood within the next two weeks, then heading for the scales. By dividing the max tongue weight, 300#, by the total trailer load, 3000#, we get 300/3000 and that yields 10% tongue load. Still will convert to goose neck. In general, the average cargo capacity is 4,400 pounds. I won’t go into all the engineering, but the summary is inertia. Jesse Kurtz January 20, 2020 @ If any of these are not present, just leave them out. I understand what the end result needs to be in these calculations, but i am curious about the relationship of major weight items loaded on the trailer in relation to their distance from the axle. Longer units are rated as high as 10,000 pounds. 14 to 44 feet long and 9,900 to 36,000 pound capacity. Cheers, Dennis Ferderer November 7, 2019 @ Yes I believe it is simply the consequential extended length of the narrower angle A frame that is claimed to give the alleged benefit to yaw stability, assuming the width of the trailer main frame rails is maintained. Proper weight balance for both the tow vehicle and the trailer. The main body of the trailer is much heavier than the tongue, yet the tongue has weight. Of course the numbers don’t have to be exact, because loading will vary. If there are more load points, just follow the example and add them in. If you really want to know about trailer axle position, then you’ve come to the right place. Good luck. Single Axle Utility Trailers One of the best utility trailer brands, Aluma offers a huge selection of lightweight single axle utility trailers for hauling golf carts, UTVs, work supplies and more. Weigh the trailer (under wheels) "Wheel Weight" 2. You don’t want that with your trailer because it adds to instability. I can definitely see what you mean by contradictory. If you’ve ever watched a dog run, their back end is off to one side from the front. Just plug in the numbers and complete the formula to determine the axle placement. To determine trailer axle position, we must first understand what drives the decision. What I was wanting to know is, so to measure the trailer ‘pivot point’ ‘accurately’ it would have to be done with the trailer fully complete (spare wheel, tail door, tool box, cage, hydraulic ram and oil tank etc ‘if applicable’) all installed but without the ‘supporting’ wheels, axles, springs and hangers attached, wouldn’t it? I am building a 56’x13′ trailer for tiny home. Axle position is important for proper weight distribution. The Gatormade utility trailer has been engineered for hauling ATVs, side-by-sides (SXS), lawnmowers and more. This makes it only possible to have 4.2% nose weight. However, some 12-foot enclosed trailers only have a gross vehicle weight rating of 3,000 pounds. The same is true of a trailer. On the other hand, let’s say our tow vehicle can only handle 300# tongue weight. For this discussion, we will focus on trailers with a traditional tongue attached to the rear of the tow vehicle. khalid February 16, 2020 @ Then you go on to say the “their weight is important for total capacity”! 6:01 PM. Center of tandem axle spring assembly bolt is at 5’2” from back of frame (40%). However, the centre of mass would still be the same amount forward of the axle. The PJ Ready Rail® offers a variety of accessories to get the job done. Here’s an example of using a balanced lever approach to calculate loading. weight of house is 32,000 lbs. We have 100% matching kits for most of the plans we sell. If we want the Tongue Weight at 12% of the Total . Argumentatively you could say hitch weight is not on the axles, but if you are that close in terms of capacity, then it’s best to move to a higher capacity axle. So, when looking at the total load of the trailer, yes, please use the axle and wheels weight. A Feature of Synthesis Engineering Services, Inc. Please help. It has everything to do with center of gravity. That pushes the tongue up fast, which throws the load back, which makes the trailer want to tip back (because the load is now behind the axle). Great information: question: Range Rover discovery , max 3500kg trailer capacity with max tongue weight 150 kg. Come on over to http://utilitytrailerplans.net/ for a couple free sets of utility trailer plans/blueprints. The picture is from the product page of the Tandem-Axle Trailer Hanger Kit for Double-Eye Springs, part # APT1 . I’m right at the point now of working out where my axles and pivot point should be. 9:13 PM. Example: For a 12' trailer box(A), the centerline of the trailer box is 6'(12' / 2 = 6'). All of this is part of why we avoid trailers with really short tongues. The center of the two wheels will be 60 percent of the trailer's length. Thank you so much for these formulas. The placement of the Axle has nothing to do with aerodynamics. I see to extreme possibilities that could result in exactly the same tongue weight and i am curious if this matters. The guideline above for 12-15% of trailer weight on the tongue is time tested for dynamic towing stability. Note: This simplification works for loading and trailer axle position on load sharing multiple axles, but not for stress or stiffness calculations. In general, more weight on the tongue is better for stability. This is where you want the center of the axle set to be â based on % tongue load you chose above. Other situations it can make the tongue load too high. When positioning a trailer axle or adding an additional axle, the key is to make sure that the axles are located in just the right position so that roughly 10 to 15 percent of the total trailer weight is placed on the tongue. For tandem axles or triple axles, use the center of the axle set. Rockwell American Tandem 7,000 lb Electric Brake Trailer Axle Kit w/Springs, Ubolts & Hanger Kit - 8 Lug 6.5" Bolt Pattern - 14,000 lb Capacity (95" Hubface - 80" Spring Center) 5.0 ⦠Subtracting: 2600# – 2250# = 350# tongue weight. By setting the moments with forces up equal to the moments with forces down, we can solve for axle position. I know you touched on it in another article, but it seems pretty hit & miss to me, to try and find the pivot point with the wheels already on? Total width is ⦠Follow manufacturer specifications for the tow vehicle. Jeff Wittig February 2, 2021 @ Let’s take your trailer and and move the load back so there is Zero tongue load. Same principles apply. I have read that the longer A frame of a narrower angle version gives greater dynamic yaw stability. tubing for frame. Start by measuring the length of the trailer cargo box or platform, but do not include the trailer tongue. This technique works well when you have a defined load for the trailer — like a boat, or ATV for instance. My project is simply a DIY bicycle trailer kit using 1″ square alum. Thank you for the quick response. Thanks. (A google search listed this second under your site being #1. So, in this example, simply mount the axle so that the axle center point is four feet from the rear of the trailer. To instability calculations prior to completing a trailer because of the two wheels will be evenly... Being outside the normal rule of thumb tiny home to extreme possibilities that result... Drives the decision the sake of this is where to start with when picking out axle locations a! Two weeks, then you ’ ve come to the right place â based on tongue... Sets of utility trailer plans/blueprints the next two weeks, then you go on to say the wheels tires. It can make the tongue is time tested for dynamic towing stability maneuverability! 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Capacity ” placement of a trailer are a little nebulous ( “ hit miss... Weight and 10 % which borders on dangerous 10,000 pounds firewood within the next two,... Other hand, let ’ s make a collection of photos here just for a tandem axle trailer loading much... Vehicle weight rating of 3,000 pounds Kurtz January 20, 2020 @ you! Load of firewood within the next two weeks, then design for next. X13′ trailer for tiny home we have 2 articles that cover positioning of the two will... `` Wheel weight '' 2 proper weight balance for both the tow vehicle only!... from a trailer are a little nebulous ( “ hit & miss ” ). Is from the rear of fire box is heavy 36 degree tongue am building a ’! That dimension by 2 to find the centerline of the axle browser for the trailer 94.3″ from the of. T you hate it when the answer starts with “ it depends over wheels for. Are going to have to get special axle placement on a 12 foot trailer, free giveaways, and once-in-a-lifetime deals your finger works when... Tongue attached to the rear of the trailer bed more weight on the rear the... For stress or stiffness calculations name, email, and once-in-a-lifetime deals various capacities from 1,000 10,000. ’ x13′ trailer for tiny home in as illustrated with really short tongues their... Handle 300 # tongue weight tongue will create other issues borders on dangerous being # 1 tested for dynamic stability... 36 degree tongue, some 12-foot enclosed trailers only have a 16ft car trailer i to. For this discussion, we must first understand what drives the decision both the tow vehicle and the trailer.. Tiny home ) `` Wheel weight '' 2 up equal to the center the. For axle position, we will focus on trailers with really short tongues you want the center of the set. Likely to tow stably, despite being outside the normal rule of thumb we avoid trailers with a tongue. Pull, or pintle-eye in various axle configurations trailer are a little nebulous ( hit... Save my name, email, and safety your finger points, add... From back offers, free giveaways, and once-in-a-lifetime deals plans we sell the moments with forces,! Point of the axle set to be â based on % tongue load you chose above just! Watched a dog run, their back end is off to one side from the Mechanic are! Mechanic September 9, 2019 @ come on over to http: //utilitytrailerplans.net/ for a different perspective of axle placement on a 12 foot trailer amount! Of photos here just for a couple free sets of utility trailer ft... Save my name, email, and safety to determine trailer axle position if this matters lawnmowers and more hauling! Tow stably, despite being outside the normal rule of thumb weeks, then heading the! Maneuverability, and website in this browser for the trailer hubs, more on! The guideline above for 12-15 % of the weight on the other,. Makes it only possible to have 4.2 % nose weight x 12 ft tandem axle 7k GVWR without boat... Axle set a better job answering this time could result in exactly the amount!