Backwards progress
I believe many products these days are inferior because sound engineering experience has shall we say been un-learnt.
I have a UK made 2015 single axle model bought new (~£22k) as "retirement van" somewhat early as my previous van was nicked.
Prepped van in January for first trip in Feb found water dripping through "roofstrap". Apparently when the manufacturer change the body panels from aluminium to polyester they didn't allow for the expansion difference of the materials and also used the wrong sealant........ whatever happened to material trials etc.
Returned from a trip in March. Is the van leaning to the nearside? Maybe I'll check the wheelarch clearance like I read on CT, yep <25mm and a relaxed axle diagnosed with the tyre wearing its way through the plastic wheelarch. On inquiring I find my plated MTPLM is the same as the maximum axle rating, now that seems to me to be asking for trouble, where is the engineering tolerance?
Hopefully the warranty will fully cover these issues, we shall see.
So much for ISO, BS, NCC, and European Community Whole Vehicle Type Approval.
I would rather have a stamp for sound engineering principles and common sense.
I also have a 9 year old van that the family borrow - no damp, no relaxed axle... why? sensible axle rating vs MPTLM, massive wheelarch clearance and scrupulous application of correct sealing materials by the manufacturer.
Comments
-
Tbh the MPTLM isn’t really that relevant if people just pile stuff in. It would also seem that one particular make of caravan suffers from a disportionate number of “relaxed axles” despite the running gear by the same these days on almost all makes.
0 -
Yes in most cases modern vans are overloaded, as most allow very slim load margins, but that's another story.
If you observe many brands exhibit a lean indicating a relaxed axle. The primary reason one brand suffers symptoms is that there is insufficient clearance between the wheelarch liner and the tyre, this ultimately leads to water ingress.
This is a design flaw in the wheelarch compounded by using full profile tyres - ie 100% aspect ratio.
Another factor is quality control of the rubber used in the suspension, incorrectly installed or cured rubber can also lead to relaxed or more accurately collapsed axle.
0 -
So going back to my OP the manufacturer has un-learned how to correctly design the suspension/bodywork aspects of a caravan. How can they allow a Tyre to foul the bodywork in any circumstances. Cars use a bump stop to prevent this. Maybe the rubber in compression suspension used in vans acts as its own bump stop at the limit of travel? I don't know. Or can the swing arm completely over rotate if the rubber gives up?
My 9 year old van as I said has a huge clearance and uses 70 series aspect ratio tyres.
0 -
Good news, both leak and axle being done under warranty what a relief!!
It does not however restore my faith that current caravan designers and engineers have lost the plot regarding quality and engineering integrity.
As I said the axle issue is not one brand, just the symptoms are quicker to show because of the tyre /wheel arch combination. Beware!
0 -
Good news. Regarding your repair.
I have seen reports of the wheel arch profile being the cause. Tbh I just don’t buy it. Also we shouldn’t call it a relaxed axle it’s a failed axle. It’s a bit like water ingress it not ingress it’s damp!
Would it be possible for you to take a look in your gas locker and tell me what the sticker in their says. With regards to the weights of the axles and mptlm.
0 -
Thanks Boff, the axle is 1550Kg max and the Mptlm is. 1550Kg max. Yes the tyre/wheelarch liner abrasion is a symptom of a collapsed axle. I suspect the rubber compound used in suspension was incorrect or not properly processed. It is like the manufacturers have forgotten how to design a proper van!
0
