Perhaps another one of those subjects that divides opinion - balancing of caravan wheels.
Before we start on the background, I'm very much in favour because I value my caravan and do what I can to preserve it in good order, and knowingly rattling it to bits with out of balance wheels doesn't seem clever.
It had come around to the time to change my tyres on sheer age (should have been done last year, but I haven't used the van for nearly a year). Because of the previously discussed debacle of failing to find any tyre fitters willing to deal with Tyron Bands that were already fitted, I resorted to taking the wheels off myself, taking them home and removing the Tyron Bands myself, before getting the best priced tyre deal from a local fitter (the Tyrons were NOT going back on! - bought a TPMS instead).
Whilst the wheels were off I had a good opportunity to study the tyre wear pattern closely, and it was VERY clear these wheels were seriously out of balance, the circumferential wear was uneven and there were a couple of more extreme wear 'spots'! They were the original tyres fitted at manufacture by Lunar, and the wheels were NOT balanced. I always inspect the tyres before each trip for sidewall cracking and in tread splits, but it's not easy to see the fitted tyres in such a way as to make judgement on wear patterns.
I watched the new tyres being fitted, and balancing was included in the price to which I was certainly not going to opt out of. On the balancing machine the wheels ran perfectly true, so no damage/distortion, but the fitter just kept adding more and more weights like I've never seen before, and he commented that he'd never seen such out of balance wheels, not just one, but both!
When I got home I totalled up the fitted weights, 115g on one wheel, 100g on the other! That's 3.5-4 Ounces, a QUARTER of a Pound on each wheel! Looking at the un-machined surfaces of the wheels (inside spokes, back of hub etc., it was obvious these were very crude castings with irregularities and asymmetry, and there were no indications of any attempts to balance the wheels at manufacture (I'm an engineer, well familiar with castings, and balancing of rotating components). The tyres (quality brand Hankook - not some budget Chinese rubbish) will have contributed to some imbalance, but most of it was the poor quality wheels! The majority of the weights were in the same area on both wheels, so a inherent manufacturing issue! It's no wonder the original tyres showed such tell tail wear patterns of imbalance.
The tyres are never likely to cover enough miles before replacement on age grounds for the wear to become a real problem, but the vibrations my van has been unnecessarily subjected too horrified me. For certain, now it has balanced wheels it's in for a kinder ride! I always speculated on just how much the contents moved around on journeys, tightening of loosened fittings was a regular task, next month I'll find out if things are better on a couple of 300 mile journeys!
I served my apprenticeship in the die casting industry and a few of the casting dies we made were moulds for aluminium wheels. However, when the alloy wheels were machined on a centre lathe, the datum in order to spin concentric to the centre were mounted on 5 central spigots at the wheel's 5 fixing points that fit to the vehicle's axle therefore they should not be severely out of balance. The only imbalance involved should be the tyre fitted on the wheel rim itself requiring the minimum amount of weights to correct the balance of the new tyre. From my experience and knowledge I would suggest that the wheels were not located on a central spindle which should be the datum point and probably fixed to the turning lathe by wheel's outer rim instead. The main problem with young engineers today in comparison to the older skilled workers is that many go to college or university and come out with a mountain of diplomas and degrees with no physical hands on experience which reflects the industry which in thread proves my point exactly.
No matter what people's opinions are on balancing caravan wheels and tyres, when you've been in the engineering industry for as long as I have, common knowledge should tell you that everything that revolves round on a spindle should be balanced. A caravan is no different to a motorhome but the true fact is that if you didn't have tyres balanced on a motorhome you would certainly feel the consequences of the vibration without a shadow of a doubt. Because people don't travel in caravans when in tow, nobody knows how exactly how severe their unbalanced tyres could be which leads to many people just being ignorant of the fact that caravan door and cupboard hinges are constantly being subject to vibration.
Tango55, these are sand cast wheels, not die cast, presumably due to the relatively small volume required and the high cost of dies, think they may be unique to Lunar, and not a stock mass produced off the shelf wheel, I've never seen the style elsewhere.
They are ridiculously heavy, heavier that the steel spare if my judgement is correct. Certainly not a case of opting for Alloys as a weight saving, purely a cosmetic thing! As sand castings go, they are a bit crude, so perhaps no wonder unbalanced!
i recently had two new tyres fitted to my van.. i had them balanced the wheels are steel.. the weights added were very small and directly opposite the valve.. they were there to counter the valve weight which isnt much..
i wrote this just to counter the miles out scare stories i am reading.. but in truth the only way to know is to have them balanced and be done with it.. but i do believe that mostly they dont need it.. mine didnt..
Nothing said about the 100% need to balance wheels that's news to me, but to correct one assumption, front wheels of MHs are balanced but do not assume rears are, infact it's doubtful they are!
Not mentioned though is tyre pressures which are just as important to ride quality as balance, these are very often stated several psi higher than required so increasing vibration as well as accentuating effects of imbalance.
Overall its not then just Hinges and woodwork suffering but all the mechanicals as well as the plethora of electronics so common in modern leisure vehicles of all types 😢
A lot of tyre firms don't bother or understand the tyre dot system (the red/yellow dots) and they don't align them with the valve, this leads to the tyres needing a lot of weights.
I always insist on any new van tyres being balanced and they are usually a bit out. I like to think that by doing so I am at least doing all that I can to ensure smooth running particularly as the van will spend quite a lot a time being towed at speeds usually associated with imbalance vibration.
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Topic: Caravan Wheel Balancing
via mobile 01/10/2022 at 11:40am
