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Hitch ball size!

Posted: Tue Jun 25, 2019 12:21 pm
by DrV
Hi there!
Normally, I sail in Mediterranean region, and I've never done towing of my 2011 :macm: to water/back. Used to hire some guy with some small field tractor, or somebody from local offroad club. But it was getting more and more complicated each summer. So, I've installed a Draw-Tite towing hitch on my Nissan Murano, and I plan to launch :macm: myself. But, I've just realized that the Towing Hitch Ball size is different in US and in Europe. My trailer is the US-model, so I want to know what ball size is used in USA for :macm: aluminum trailers. Is it always 2inches = 50.8 mm? Being thousands of miles away from my boat, I need to know for sure.

The European tow-ball size is 50.00 mm. That is 0.8mm (1/32 in) difference compared to US size. The off-road club guys and farmers never bothered about the difference (I guess they never even noticed it). Should I? What happens if I tow 50.8mm trailer with 50 mm ball? Is it likely to fall out, and is it necessary to change the ball to US standard? Safer - YES, but is it really necessary?

Re: Hitch ball size!

Posted: Tue Jun 25, 2019 12:43 pm
by Tomfoolery
If it were me, I'd just use the 50mm ball and not worry about it. Adjust the jaw for a snug fit with the lever down (or up, depending on the coupler). U-Haul rental trailers fit both 1-7/8" and 2" hitch balls, since the jaw is manually screwed snug. But all couplers that I'm familiar with have an adjustment on the moving jaw, and 32 thou isn't going to make any real difference if you adjust the coupler for a snug fit.

It's not like those couplers are precision machined to start with - I can see wear marks on just three places on my chrome hitch ball from the two points of contact in the upper-front (where the formed part touches) and the lower-rear (where the movable jaw contacts it underneath). The hitch would have to lift off the ball to get loose, and if the jaw is adjusted properly, it's not going to be able to do that even with a (very) slightly smaller ball.

But if you can find a real 2" locally, or bring one with you when you fly there, assuming you're in North America when not sailing, then you could always do that. 8)

Oh, and if it's a US trailer, it's always a 2" ball. The only other size near that is 1-7/8", and that doesn't have the capacity at 2000 lb (typically). or 2-5/16" diameter for really heavy trailers, like portable buildings and very heavy boat trailers and big bumper-pull RV trailers (like 12,000 lb and higher).

Re: Hitch ball size!

Posted: Wed Jun 26, 2019 6:54 am
by MacAxel1
The minimum allowed size for a hitch ball in Europe is 49 mm. However it seems they are 50mm when new and in reality are more in the range of 49.5 mm.

Question would be what the minimum allowed size for the hitch ball in the US would be. Quick google gives 1/8 inch (3mm) reduction is ok, so the 49 mm would be fine.