5x5 or 5x4.5 bolt pattern on trailer

[frostyflammable]

So I am a little confused, I measured my wheel pattern on my trailer and the way I was taught on a 5 lug is to measure from the end of one lug to the middle of a lug that crosses the hub (picture attached). From that I got a 5x5 pattern. The reason I am confused is that I emailed etrailer to see what drum I should get and I was told that I have a 5x4.5 pattern since I am supposed to measure center to center.

I was hoping someone here can clear things up, with the pic provided do I have a 5x5 or 5x4.5 bolt pattern?

Thanks.

 

[mckutzy]

Off hand this is what I found for this....

 

[frostyflammable]

Oh i see, different way to measure for trailers. Center to center on trailer wheels.
Nice never knew there was a different way to measure the pattern on a trailer, learn something new every day.

Thanks!

 

[itsid]

since they all determine botl hole CIRCLES

I found it easiest with the wheel installed, then measure from the center of the hub to the center of one bolt, and multiply by two (for no matter what number of bolts)

Sometimes the dead center of the hub is hard to determine I admit,
especially if it's sticking out as far as yours in the pic.


So just as a tipp that often holds true for automotive rims at least in europe:
mounting details are stamped to the inside of the rim
so you often find a series of numbers on the inside like say 5x108 54 ET 30
means five bolts 108mm bhc 54mm center hole 30 mm offset

it's nice and reliable and I cannot remember a wheel w/o

'sid

PS mathematical calculation of bolthole circle by bolt distance:
center to center of two adjacent bolts (as length a)
a * sqrt(50+sqrt(500))/5 = x [where x is the bhc]
(roughly a * 1.7)