Selecting Correct Hub

[AguaSki]

Been boating for years, but like so many others I have neglected my trailer wheel bearings. Fortunately I have not had any problems, but I know I am on borrowed time. I really hate my hubs. The hubs have threaded holes that use bolts to hold my wheels to the hub. It is a pain to get the wheel lined up perfectly on the hub and then insert a bolt into the thread. I would rather have hubs that have threaded studs that stick out so that I can then fasten the wheel with lug nuts the same as most autos. Since it is time to address my neglected wheel bearings, I figure now is the time to purchase new hubs that use studs and lug nuts. After pulling the hubs off my trailer this is what I know.

* My rims have a 5 hole pattern
* The outer portion of the shaft is 1 1/6 (measured with calipers)
* The inner portion of the shaft is 1 3/8 (measured with calipers)

I have found several hub kits for sale on the web that match the measurements of my shaft so I am confident I am on the right track. This is my question, some of the information I see will say 5 on 4.5", and others will say 5 on 5". So, what does the 4.5" and the 5" represent? My guess is this measures the diameter from the center of one bolt hole directly across to where the center of an imaginary bolt hole would be located. Because I have a 5 hole rim, there is not a hole directly across from another hole, so I have to measure to an imaginary hole. If I had say a 6 hole rim it would be easy to measure from hole to hole, but I can't do that with 5 holes. Am I correct in how I am thinking about this? If I am understanding this correctly, then I have a 5 on 4.5".

Just want to be sure I understand what I am buying so that I can quickly install the new hubs and go boating. Please share your thoughts on this. Thanks.

 

[Wishiniwuzfishin]

Re: Selecting Correct Hub

To measure a 5 lug hub you would measure from the center of 1 stud to the center of 1 of the 2 farthest away studs(or center of holes in your case). You do not measure straight across to an imaginary stud. To confirm this just do a web search "how to measure bolt pattern".
EDIT: correction.....apparently the measurement is from the center of 1 stud to the BACK of 1 of the 2 farther away studs (or holes).....just learned this myself
Do the search and you will see diagrams making it clear.

 

[AguaSki]

Re: Selecting Correct Hub

Thanks for the information. Your idea to do a Google search helped. Below is a link that I found.

http://www.mrt-wheels.com/boltpattern.html

This website mentions using the same process you described, center of one hole to the back of the the third hole. But, the website also mentions this is an estimate for 5 hole bolt patterns. The website also shows that when measuring 4, 6, and 8 hole patterns you go from the center of one hole directly across to the center of the opposite hole. Using this logic, I could probably take a pencil and draw a circle that connects at the center of each hole, and then measure the diameter from the center of one hole to the pencil mark across from the hole. This gets back to my imaginary hole theory. I think I need a 5 on 4.5".

Please chime in if others have thoughts.

 

[AguaSki]

Re: Selecting Correct Hub

Think I have this figured out, but I will post one more website I found so that this can help someone out in the future.

http://www.bageco.com/boltpattern.htm

This particular website says 5 bolt holes with 4.5? measure to a point halfway between the opposite bolts. This supports my original imaginary hole theory.

The problem I have with using the center of hole 1 to the back of hole 3 is it is not exact. When I run my tape measure I end up getting 4 11/16" or 4.6875".

The first website in my second post mentions a 3rd option that uses a multiplier of 1.05 to correct the estimating error. This 3rd option measure center of hole 1 to the center of hole 3, and then multiply by 1.05. In my case I measured 4 5/16" or 4.3125". Multiply that by 1.05 and I get 4.528". Once again I think I am back to needing a 5 on 4.5" hub.

I think my problem has been solved but thought I would share in case the information is helpful to anyone. Still open to additional thoughts if there are any.

 

[Silvertip]

Re: Selecting Correct Hub

A circle has a center and whether there are 4, 5, 6, or 8 holes makes no difference in how it is measured as there are several methods, some of which have been covered. The simplest is to measure from the center of the large hole to any of the lug bolt holes and multiply by 2 as you just measured the radius of the bolt circle. There is 1/4 inch difference between the radius of a 4.5 and 5 inch bolt circle. That much difference is clearly visible when eyeballing the center of the wheel.

 

[Rocky_Road]

Re: Selecting Correct Hub

If you have a wheel off...and you are buying your hubs locally...you could match it up at the counter. The hub will be a very simple "go-no go" fit!

Happy boating!

 

[woosterken]

Re: Selecting Correct Hub

what i did, thats WAY CHEAPER than replacing the hub.
i got two bolts with the same thread size as the lug bolts, cut the heads off and put a slot in them (just in case ) then put them in oppisite holes,start the other two lug bolts and then remove the stunds one at a time to replace the lug bolts.
i only have the 4 bolt pattern on my wheels

woosterken