Loader Specification Primer
Image from New Holland
How critical of an eye do you have when looking at tractor specifications? Do you pickup on things like pivot pin and bucket center measurements? How much work can these tractors really do anyway? These factors are important when analyzing and comparing all the different products offered in the compact equipment market. In a competitive world with dozens of companies fighting for your dollar each may choose to employ a few tricks of the trade to win your business.
For years loader measurements have always been taken at a point called bucket center. On our diagram above that's point V, right at 500mm forward of where the bucket mounts onto the loader arms. This point of used as it represents the center of most loads that the machine may lift. Regardless if you have pallet forks, a bale spear, or an oversized bucket of snow, this measurement is a good estimate of what you can expect to lift with a tractor. There are industry standards that regulate how this measurement is taken and our own testing confirms that you can expect these numbers to be true to real world performance.
Its becoming more common for sly marketing departments and salespeople to use pivot pin measurements instead of the tried and true bucket center. Generally pivot pin ratings are about 30% greater than those taken 500mm forward. On our chart the pivot pin is marked with a U. This measurement is also backed by industry standards, but it has no real world use since tractors do not lift any loads from this point. Its a largely useless figure, but its bigger, and big numbers sell.
Both bucket center and pivot pin measurements are taken at the full lift height of the loader. Its very uncommon to see measurements taken from lower heights. These figures can also show exaggerated results as loader capacity decreases are height increases. Loader and bucket breakout forces are taken at ground level and reflect this. These measurements should be taken at point Z on our chart, but are sometimes also taken back at the bucket pin.
The same skewing of numbers can be done at the three point hitch. Most times the 24" measurement is used which gives an approximation of where a load would be centered on the back of the tractor. Just as with the loader as you move the load to the rear physics dictate that the capacity drops sharply. Three point hitch ratings are occasionally seen at the ball joints and reflect inflated numbers.
There are many culprits who use deceptive specifications. Without pointing fingers the biggest offenders tend to be foreign companies trying to get a foothold in the US market. These tactics offer a quick way to make it appear as if you are offering more than the large contenders. As of now the only companies who are still 100% honest with every specification are Case / New Holland and Kubota Tractor. These companies are surly feeling the pressure to take the same route are their competition.
An excellent write up on this topic has been done by Bob Surka, reposted with permission.
FOR EXAMPLE, I just pulled up tractor specs for 3 small frame compacts. One from a Big 3 company, 2 from popular minor brand companies. This EXAMPLE just to show how the numbers APPEAR on the surface!
Big 3 Stats in their MARKETING stuff:
FEL capacity = 750#
Breakout = 1220#
3pt capacity = 1265#
Minor Brand #1 stats in their MARKETING stuff:
FEL capacity = 1074#
Breakout = 1511#
3pt capacity = 1109#
Minor Brand #2 stats in their MARKETING stuff:
FEL capacity = 915#
Breakout = 1828#
3pt capacity = 1400#
NOW IF WE EQUALIZE ALL THESE NUMBERS to the SAME MEASURING POINTS, the numbers look something like this:
Big 3 brand capacities =
FEL capacity = 1090# @ the pivot point . 340# MORE than their "marketing" claims
Breakout = 1720# @ the pivot point . 500# MORE than their "marketing" claims
3pt capacity = 1265 @ 24" behind the ball eyes
Minor Brand #1 capacities =
FEL capacity = 1074# @ the pivot point
Breakout = 1511# @ the pivot point
3pt capacity = 1109# @ 24" behind the ball eyes
Minor brand #2 capacities =
FEL capacity = 915# @ the pivot point
Breakout = 1828 @ the pivot point
3pt capacity = 980# at 24" behind the ball eyes. 420# LESS than their "marketing" claims
The above "Marketing" numbers are based on the marketing materials I was able to find on the various websites (the 980# capacity was listed on a competitive site, it is not a calculated number).
Now if we want to make the FEL numbers HONEST and we can calculte them DOWN. Doing so will make the numbers look like these (these are calculated so all the capacities drop the same % with the same distances)
FEL capacities @ 500mm forward of the pivot point (calculated if not claimed)
Big 3 FEL capacities =
FEL capacity = 750# as claimed in their marketing material
Breakout force = 1220# as claimed in their marketing material
Minor Brand #1 capacities =
FEL capacity = 739# 335# less than their marketing material
Breakout force = 1072# 439# less than their marketing material
Minor Brand #2 capacities =
FEL capacity = 630# 285# less than their marketing material
Breakout force = 1296# 532# less than their marketing material
--- My point with all of this is that this is DECEPTIVE and ANTI-CONSUMER. ---
While I pulled an example of 1 "Big 3" brand and showed it against 2 similar tractors from "Minor" brands in this particular example, that is only to illustrate my point. I think there has been ample evidence to suggest that at least 1 "Big 3" brand uses confusing data in at least SOME of its marketing stuff. And this example also shows that the "Minor" brands do not agree on how to measure 3pt capacity because Minor Brand #1 measured at 24" behind, while Minor Brand #2 measured at the ball eyes. So it just further illustrates the confusion.
Now to address your question of HOW to calculate it, the absolute best answer is NOT to calculate it at all but to find the actual numbers. Sometimes those are VERY elusive indeed. So if you have to calculate it, it is safe to reduce capacity by 30% to 35% as you go from the PIVOT POINT to the center of the FEL bucket. It is also safe to reduce capacity by roughly the same amount as you go from the ball eyes to 24" behind the ball eyes on the 3pt hitch. The ACTUAL decrease will vary slightly from manufacturer to manufacturer, but 30% puts you in the ball park, 35% may give you some safety margin. When calculating BREAKOUT FORCE, again, figure 30%.
Now if you ask where these 30+% numbers came from that I keep throwing out, then go back to the DETAILED spec sheets that SOME of the manufacturers provide. I looked over several different brands, I did the math myself (subject to my error) but when I used the manufactuer's numbers, the capacity drops were roughly 30% some were higher, occasionally some were as low as 29%! And it varied with tractor models and loader models and 3pt hitches within any given manufacturer and I did not calculate every tractor by every manufacturer, I simply picked a couple popular models dug until I could find what I was looking for.