Towbar mounted 4-bike rack swivelling

[symowallo]

Hi, I have a towbar-mounted bike rack - it's one of those racks that has 2 main supports so that you can still use the towball while the rack is mounted.

Its plate sits on top of the towbar tongue, and the towball goes through it, so that the tongue is on the bottom, the bike rack's plate is next, and then the towball sits on top of that.

The first time I attempted to use it, carrying 2 bikes, I struck a problem. When I turn corners in the vehicle, the bottom plate rotates which therefore becomes a dangerous situation because the bikes rotate with it. I've tried tightening the crap out of the towball but that doesn't stop the problem. I've contacted the vendor who had no suggestions other than maybe a couple of bits of rubber on the top and bottom of the rack's plate. Surely others have experienced the same issue? Any suggestions appreciated!

Thanks in advance!

[open roader]

Have a small steel plate flush with the rack mount welded onto the top of the tow bar tongue - seen this done several times to remedy involuntary rotation on tow ball mounted devices.

[symowallo]

Thanks Open Roader.

Should this plate be L or U shaped so that it prevents the base from moving? Ie. So it sort of "cups" the base?

[mithba]

Surely you could simply weld two bits of metal on the tongue on either side so that when the rack mount tries to swivel it just hits the metal? you could even just weld on 2 nuts.

Please excuse my bad MS Paint skills.



the red circles represent welded on "nuts" or whatever type of obstruction you choose.

[bychosis]

Or you could put them on the rack if you don't want to damage the integrity of the tow bar.

[queequeg]

I had the same problem. The towball was rotating in the tongue due to dodgy spring washer. I had a new ball and washer fitted and have not had an issue since.

[symowallo]

Good ideas everyone... I like the idea of welding on a couple of tabs. I don't have a welder but it'll be an easy job for the local workshop...

[Dan's Avanti]

Yep, same problem, I had a single small tab welded onto the rack. Easy and effective.