Axle capacity 1" spindle

[Moody Blue]

Have searched for info on axle capacity for 1" spindles but found nothing.

Anyone know for certain what the load rating is for 1" spindle size?

 

[Mark_VTfisherman]

Re: Axle capacity 1" spindle

That is an odd question.

Tires that fit the wheels made for that size bearing/hub have a rating. I would think any load that does not exceed the cumulative tire rating per tire would be fine. The registered gross weight of a trailer can't exceed the combined tire capacity.

 

[kandil]

Re: Axle capacity 1" spindle

Leaf spring has to do with the axle capacity

 

[Moody Blue]

Re: Axle capacity 1" spindle

Both statements are somewhat true but not technically right.

Tires of any given size come in multiple load ratings. In some cases you can install larger tires onto the same hubs (bolt pattern). Tire size does not determine the axle capacity but merely indicates the capacity of the tire.

The same is true of leaf springs. I could install leaf springs rated at 4000Lbs that could easily exceed the axle capacity.

The true axle capacity is determined by the spindle/bearing sizes.

 

[Mark_VTfisherman]

Re: Axle capacity 1" spindle

http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200334714_200334714
1250 lbs

 

[Boatdood]

Re: Axle capacity 1" spindle

Typically the rated capacity of a 1" spindle is 1000 lbs. You can connect springs and tires and even a hub that can carry more than that but the weakest link would still be the spindle.

 

[Mark_VTfisherman]

Re: Axle capacity 1" spindle

Typically the rated capacity of a 1" spindle is 1000 lbs. You can connect springs and tires and even a hub that can carry more than that but the weakest link would still be the spindle.

The bearing is the determining factor here...

A 16 penny nail is .135" in diameter and will support over 190 pounds. It is usually rated in application around 118 pounds shear. 8 of them equal about 1" if stacked up side by side- about 1000 pounds of combined shear strength. A 1" spindle has substantially more steel in cross section- the spindle itself is naturally much greater in strength than the 1250 lbs. given.

Therefore the bearing is the determinant excluding tires and springs. Tires, however, are most often the weakest link on small trailers in my opinion.

 

[reelfishin]

Re: Axle capacity 1" spindle

Most trailer axles advertised as being 2000 lb capacity use 1" spindles, some newer ones have gone to 1 1/16" for that rating.
Not many axles use a spindle under 1" these days, even my 800lb capacity trailer has 1" spindles, and that is only sprung for a 12' aluminum boat.

Actually capacity can vary by the tubing size and how it's built.
I had a tandem axle trailer rated at 4200 lbs and it used 1" spindles and 2" square axle tubes.

 

[Boatdood]

Re: Axle capacity 1" spindle

The bearing is the determining factor here...

A 16 penny nail is .135" in diameter and will support over 190 pounds. It is usually rated in application around 118 pounds shear. 8 of them equal about 1" if stacked up side by side- about 1000 pounds of combined shear strength. A 1" spindle has substantially more steel in cross section- the spindle itself is naturally much greater in strength than the 1250 lbs. given.

Therefore the bearing is the determinant excluding tires and springs. Tires, however, are most often the weakest link on small trailers in my opinion.

Interesting analogy Mark. Remember though that we are not considering the shear strength of the spindle, but rather its resistance to bending, which is considerably less. You know how easy it is to bend those nails.

 

[Silvertip]

Re: Axle capacity 1" spindle

The spindle referenced in the link above is rated at 1250# so that times two = 2500 pounds. That is however a real push on an axle with one inch spindles. That's over a ton on a spindle that is about the size my thumb. Look for a tag on the axle itself. If it's a newer axle it will indicate the actual "axle capacity" on the tag. Even though the spindle is rated for 1250#, it may be welded to a tube that has a capacity of only 2000# or worse 1500#.

 

[Boatdood]

Re: Axle capacity 1" spindle

The spindle referenced in the link above is rated at 1250# so that times two = 2500 pounds. That is however a real push on an axle with one inch spindles. That's over a ton on a spindle that is about the size my thumb. Look for a tag on the axle itself. If it's a newer axle it will indicate the actual "axle capacity" on the tag. Even though the spindle is rated for 1250#, it may be welded to a tube that has a capacity of only 2000# or worse 1500#.

The link referenced above takes us to a hub assembly designed to fit a 1" spindle. The capacity of that hub is rated at 1250 lbs., not the spindle it's designed to fit on. Here's a link referencing an axle equipped with those hubs.

http://www.northerntool.com/webapp/...en=natural&cm_cat=netconcepts&cm_pla=&cm_ite=

As you can see in this link even though the hubs have a 1250 lb capacity, the axle with those 1" spindles is limited to 2000 lbs.

Think about it guys. You have an axle and then you have a list of variables. You can put hubs on it with more or less capacity. You can put springs on it with varying capacity. You can even put tires and wheels on it with more or less capacity, but nothing you can do after the axle is built will alter the capacity of those spindles. Typical axles used for many years in boat trailers were rated at 1000 lbs for a 1" spindle and 1250 lbs for a 1 1/16" spindle. That rating takes into account the expected margin of safety required for potholes and such. We can have exceptions to this rating but then we wouldn't have typical axles.

 

[Mark_VTfisherman]

Re: Axle capacity 1" spindle

...You know how easy it is to bend those nails.

And I really hope they don't use that steel making the spindles either

...You have an axle and then you have a list of variables

That was why I stated right off that that was an odd question

A 1" spindle even of different alloys and manufacturers may even have a different rating. Silvertip was right when he pointed out axle construction, too.

I couldn't find a 1" spindle but didn't look extensively either. Tie Down Spindle Manual shows 1-1/16" as sold here: http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200365154_200365154

Good luck!

 

[reelfishin]

Re: Axle capacity 1" spindle

1" spindles are slowly going away and being replaced by 1 1/16" size on most boat trailers. Only the super light duty trailers usually come with 1" spindles now as a rule.

A lot has to do with how and to what that spindle is attached to. a short length of 1" bar stock will take quite a bit to bend or shear.
Most axles I've seen damaged by overloading have bent either over their entire length or just beyond the spindle.

The one trailer I have with 2" square axle tubes and 1" spindles is rated at 4200lbs on the tag, it's a tandem trailer with 4 13" wheels. No doubt on that trailer, the tires are it's weakest link. It came new with a 1800 lb trihull.

I would also venture to guess that most 1" spindles are not made of any special steel. Most are made with plain mild steel. In general you would prefer a spindle to bend rather than break. Its not a wear item and making it harder than needed will only increase it's likelyhood of shearing if it's max load is reached. One major concern when welding on a new spindle is that the welding process can harden the spindle where it meets the axle. Its common practice to anneal the entire axle for strength after welding to eliminate any stress. I've built many axles with 1" spindles and have never yet had one fail.

An axle that bends or deflects under load is also less likely to not break or shear. You don't want the weak point to be the spindle to axle joint.