Al-Ko tow hitch

[xtrailman]

Awe come on guys its only a tow ball for christ's sake

and parksy's wonders why I don't want to do technical stuff any more.
struth I can understand the alko stand point in a way as the pads have to grab the ball there must be a limit to when effeciency is lost 1mm seems fair but a european directive on the subject when alko hitches are not compulsory god they will be telling us the minimum paint thickness on the tow bars next!!! as if the ministery men will be stopping us on route now measuring all the tow balls.
mines not even a alko ball but a witter one came with the bar do I care "NOPE" what does it measure "no idea" I will test it tomorrow with my spirt level and let you know if you like. go on tell me it's dangerious not to have the """ alko ball well its only been in use 3years and doesn't foul anywhere, besides what about changing the ball every time you tow a different trailer yer right.

Now calm down Colin.
Lutz and i are only playing with each other.
Besides Lutz latest post has reassured me.
I had assumed because the ball was used dry, that wear would have been more substantial. My own measurements confirm what Lutz has said, i see very little if any wear, and i have a new ball to check against.
I completely disagree with your comments "its just only a tow ball". Its the only thing that attacher's the caravan to the car.
Personally i would like it to keep attached to the car, something that a worn ball may struggle to do?

 

[Dustydog]

I've asked Al-Ko for a comment here. Doubt we will hear but at least they have been publicly asked.

I wonder what BPW have to say?

Additionally how about the hitch itself? How do you measure that ? What is the Al-ko wear guideline and the EU boys??

 

[Lutz]

I doubt whether BPW would say anything as they don't produce towballs nor couplings with pads (they use Winterhoff stabilisers).
The regulations do not specify any particular dimensions for the hitch, just performance requirements (strength and durability tests) in conjunction with a towball of the dimensions and tolerances as defined. In other words, the hitch must be suitably matched to the towball.

 

[xtrailman]

Isn't the wear on the ALKO, pad wear. not sure.
But wear indication is on the AKS body.
tells you when the pads are worn.

 

[colin-yorkshire1]

I completely disagree with your comments "its just only a tow ball". Its the only thing that attacher's the caravan to the car.
Personally i would like it to keep attached to the car, something that a worn ball may struggle to do?

Ok Ray so my comments were meant to be "odd ball" and funny but you have to see the irony in all this.
I especialy like the "Personally i would like it to keep attached to the car, something that a worn ball may struggle to do?" because the ball is locked onto the hitch by the under shoe the gap between the shoe and the hitch body is only 36mm so the ball would have to be worn down to minus 40mm before it popped off which makes the regulation Lutz spoke off seem rather obscure.

 

[RegandPat]

Hi all, at last I have the new tow ball fitted to my Jeep and the old one will go to the tip.
What a job to do, ah you say easy, I got two sockets on the bolt and nut with a two foot bar and crack went my ribs.
After pain had subsided I jumped on bar, big mistake, bent bar.
Take Jeep to new son in laws (strong lad) bigger bar but got one bolt off but the second one would not budge.
Mate down the road said he would have a go so drove Jeep down to his house, he produced a big air gun, like the ones they change wheels with, well it did struggle but hay presto off it came, new ball fitted with gun.
Now your going to kill me, how do I change my pads in the AL KO hitch or at least how do I get them out to checks them.
PS. please no arguing it upsets the dog.
Thanks Reg

 

[ProfJohnL]

Hello Reg

It is always sensible to check for wear, but I seriously doubt that you will have an undersized (i.e. less than 49.61mm OD) ball. If you do, then it will be due to either a material fault in the manufacture of the ball or excessive (probably commercial) towing.

I have to say that there were some rather silly and pointless comments made in some earlier posts that had nothing to do with this thread.

For what its worth;

There are two parts to the coupling the ball and the hitch.

In practice there is likely to be relatively little wear to the ball over the life in a caravanner's hands so whilst it is always wise to check diameter, I would not anticipate any normal tower finding a substantially under sized ball.

The Balls are made from a hard and durable material and the articulation motion between the ball and hitch is quite restricted, so the opportunity for wear is minimal.

In the case of the Alko hitches, compound friction pads make contact with the ball and these are much softer than the ball material and are designed to be sacrificial, so ball wear should be minimal. In conventional hitches, the systems should be relatively close fitting and lubricated, so again the opportunity for wear in a properly maintained system is again minimal.

It makes logical sense for that the largest possible ball must work with the smallest possible hitch and vice versa, and that condition is assured by the EU directive EC 94/20.

With regards to the specifications that have been mentioned. I have reviewed directive. Just as Lutz states the legal ball major diameter is stated as 50 h13 which calculates out to a minimum diameter of 49.61mm. Any ball that is less than that is no longer compliant and would be considered illegal.

As anyone who works with compliance to standards will recognise, that the standards are the minimum required for compliance, and there is nothing to prevent a manufacture from exceeding a standard, where the function or safety of a produc/systemt is enhanced. In fact that situation is encouraged.

As far as the hitch manufacture is concerned, their product must function with the standard ball. There is nothing in law that stops them form using a design that can continue to function with technically illegal undersized ball, That is a measure of the manufactures design margins.

So it it perfectly reasonable for Alko to quote operations with 49mm balls. It is important to note that Alko also state they comply with EC 94/20, its just that they choose to exceed the specification. Just because the Alko system will work with undersized balls does not make it legal to use an undersized ball, Nor does it suggest that balls should be allowed to reduce in size below the legal limit.

Therefore I conclude that both Lutz and Ray's position actually compliment each other rather than oppose.

 

[Dustydog]

Here's the definitive response from Al-ko. I bet their web site and written literature now gets changed

The specification details for the tow ball diameter are a 49.61mm - 50.00mm. Effectively, the tow ball should not be any smaller in diameter than 49.61mm.

Regards
Alan Sanders
Service Manager