Question about tow-ball mounted carriers.

[Pauluk]

Hi

I've just had a tow-ball and tow-ball mounted cycle carrier professionally installed as I was finding fixing my roof bars and carriers a bit tiresome, not to mention lifting our bikes onto the car roof becoming more of a strain as I get older.

The installation seems to have gone fine but I was a bit surprised as to how much the loaded carrier moves and flexes. Its rigid at the tow-ball (nice and tight) but when holding the bikes I can flex the whole assembly in a side to side movement. I've not measured this movement but I would think its somewhere around 1 to 2 cm.

My cycles are well within the weight spec for the carrier and the whole load is within the weight spec for my car.

Am I right in assuming this flexing is normal and that these racks couldn't be completely rigid.

I've never used these types of rack before so I'm hoping some of you more experienced folk may be able to put my mind at rest.

 

[mrandmrspoves]

I must admit that when I first started using my Thule tow bar mounted rack I was quite nervous and half expected it to drop down and drag along the road. It has now performed impeccably for about 2 years. It is strong enough for me to sit on so it should manage my bikes.
I am not sure about the play you describe so would certainly advise getting it checked. What rack did you go for?

 

[Pauluk]

Its a Witter tow-ball and rack. It's not play exactly. I can only describe it as flexing.

 

[boydj]

I've had a Thule towbar-mounted rack for a few years with no problems. I think a bit of flex is to be expected since you have a relatively large structure supported at a single point.

 

[Spinney]

I've got a Thule one. It flexes. In the rear view mirror I can see the bikes moving a bit, even though all the straps are done up tight when I check.

You'll stop worrying after a few journeys....

 

[Pauluk]

Thanks for the replies. I did think some flexing was normal but wasn't too sure. Feel a bit better now

 

[Richard A Thackeray]

Does it clamp onto the ball, or has it got a mounting plate between the ball & mounting flange for the M16 bolts..

If it clamps directly onto the ball, try cleaning the ball with a proprietors brake cleaner solvent, or petrol (not diesel!) to remove grease/oil which may allow movement.

That said, it is more than likely inherent flex in the rack.


Nb; I hope that you've remembered a lighting board & number plate on the rack?

I have some picture somewhere of the last tow-bar mounted rack I had, complete with lights,& 'width-markers' (as fitted to the sides of caravans)

 

[XRHYSX]

Does it clamp onto the ball, or has it got a mounting plate between the ball & mounting flange for the M16 bolts..

If it clamps directly onto the ball, try cleaning the ball with a proprietors brake cleaner solvent, or petrol (not diesel!) to remove grease/oil which may allow movement.

That said, it is more than likely inherent flex in the rack.


Nb; I hope that you've remembered a lighting board & number plate on the rack?

I have some picture somewhere of the last tow-bar mounted rack I had, complete with lights,& 'width-markers' (as fitted to the sides of caravans)

Why not diesel? its what I use to wipe grease off the air lines of my lorry

+1 for the light board and reg plate, if not already fitted

Do you have a rack that holds the wheels or the top tube?

A bit of flex is to be exepeted, its just because you can see it in your rear view that it makes you nervous

I don't like the roof mounted racks, have you seen how much the bikes move about on them

This is my bike rack, just a cheep H@****ds one, but works a treat

 

[Richard A Thackeray]

Why not diesel? its what I use to wipe grease off the air lines of my lorry

+1 for the light board and reg plate, if not already fitted

Diesel's great for removing grease, but......if the rack is on of those that actually clamps onto the ball, diesel doesn't evaporate & leaves an oily film, thus the racks my move slightly


The same goes for any caravanists out there, who may use ALKO, or Winterhoff hitches that have the pads for the anti-sway in the hitch head; grease contaminates the pads, reducing their friction, & they can't control the snaking correctly

 

[Salad Dodger]

On our campervan, we have a tow ball mounted "Diamant" bike carrier. It pretty similar to a Thule multi bike carrier, in that it just clamps tight onto the tow ball and there is no other fixing point.

We usually carry 2 adult e-bikes. About 20 kilos each (the carrier is rated for max 60 kilos).

The carrier does flex a bit on bumps, but we have used the carrier for 4 or 5 years now with absolutely no problems at all. So yes, I guess it is intended to flex a bit.

Incidentally, what I have done is to go to Halfords and bought 2 of these
http://www.halfords.com/webapp/wcs/..._productId_222837_langId_-1_categoryId_202502

and I fix the hooks to the top edge of the back doors of the van, and tie them to the bikes. I figure that if the carrier should start to slip down towards the road, the "back up" straps will hold it in place until we can stop safely and sort it out.

 

[Sterba]

I don't want to make you feel nervous, but when I used to use a ball-type tow-hitch for a bike rack, I always felt the need to check that it was tight after I had got the bikes on, which is a bit difficult to do. So remember to do the tightening before you put the bikes on! Other than that, I never had any trouble, and yes, the bikes used to look as though they were about to bounce off when I watched them in the mirrors, but they never did. Don't worry about the flex, if the unit was too rigid, then it would be more likely to fracture.

In North America, they don't use ball hitches for this purpose. Instead they have the kind of hitch which just ends in a small square hole of angle iron, a female into which the matching male of the rack fits, then a small vertical pin to stop it falling out again. No chance of the rack tilting.