webbocj Posted October 8, 2007 Share Posted October 8, 2007 Having read recent threads regarding tyre pressures and also valves i wondered if the following would raise any comments. Brand new m/h in June, smart alloy wheels (obliged to buy as part of extras package), not cheap but look good! complete with Continental Vancocamper tyres. When i noticed that the N/S FRONT had 16 balance weights stuck on, i pointed it out to the dealer who in their normal laid back way offered to have them balanced, they were balanced and true, so what was the real reason for such a large amount (8@10+8@5=120grms?=4oz in English, almost a 10inch strip) alloy rims engineered and top of the range tyres, feel all is not correct and on the front, runs great!! Link to comment Share on other sites More sharing options...
davenewellhome Posted October 8, 2007 Share Posted October 8, 2007 It used to be the case that tyres were engineered with a slight heavy spot designed into them to counteract the weight of the valve. The heavy spot's position was denoted by a red spot and they were supposed to be fitted with the red spot diametrically opposite the valve. This should minimise the need for balancing weights to be added. I don't know if this is still the case but I have seen a red spot on many new tyres and it's rarely in the correct position (assuming its still there for the same reason). As long as the wheels are balanced then there is no real problem with the large number of weights you found other than cosmetically spoiling the appearance of the nice shiny alloys. I am intrigued as to why it was obligatory to buy the extras pack though. D. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted October 9, 2007 Share Posted October 9, 2007 Big wheels and big tyres sometimes need big balance weights. Adjusting a tyre's position on the wheel may well allow balance to be obtained with fewer weights - trouble is you don't know how much weight is required before the wheel is initially balanced and, once it's balanced, the tyre-fitter will be reluctant to re-balance it just for appearance's sake. A competent tyre technician with suitably modern equipment should normally be able to balance alloy wheels so that all the weights are on the inner side of the wheel and hence invisible when the wheels have been fitted to the vehicle. I smiled wryly to myself when I read your comment about "alloy rims engineered and top of the range tyres"!!! Link to comment Share on other sites More sharing options...
webbocj Posted October 9, 2007 Author Share Posted October 9, 2007 The Knaus Van Ti according to the advertisement starts at"from £32k" but was launched in the top of the range livery (as seen by most people) at £37k silver/alloys/bigger fridge/cab ac/and a few other things. The £32k i beleive would be white and not available until 2008!!! Very much a sales pitch. The only slightly different model i have seen as got silver painted wheels. As you will be aware minor changes are made almost daily? e.g a grey sealing strip on mine(matches colour scheme) was seen at the same dealers in White! current models(6months on) dont have it at all Link to comment Share on other sites More sharing options...
webbocj Posted October 9, 2007 Author Share Posted October 9, 2007 I obviously assumed incorrectly, ismile when i think of Lewis Hamilton speeding round with 16 lumps of lead stuck to his wheels. Link to comment Share on other sites More sharing options...
webbocj Posted October 9, 2007 Author Share Posted October 9, 2007 Just a thought, are not wheels balanced inner and outer for practical purposes, and therefore cannot be moved for cosmetic appearances? Link to comment Share on other sites More sharing options...
Derek Uzzell Posted October 9, 2007 Share Posted October 9, 2007 Dunno. My local tyre-fitter says he can 'balance from the inside'. I know if I'd paid magabucks for a supercar I wouldn't be over-keen on having sticky lumps of lead visible on its hyper-expensive wheels. Link to comment Share on other sites More sharing options...
Guest starspirit Posted October 9, 2007 Share Posted October 9, 2007 davenewell@home - 2007-10-08 9:57 PM It used to be the case that tyres were engineered with a slight heavy spot designed into them to counteract the weight of the valve. The heavy spot's position was denoted by a red spot and they were supposed to be fitted with the red spot diametrically opposite the valve. This should minimise the need for balancing weights to be added. I don't know if this is still the case but I have seen a red spot on many new tyres and it's rarely in the correct position (assuming its still there for the same reason). D. Dave, forgive me for asking, as I do greatly respect your experience and knowledge but I thought the red spot was placed at the point on the tyre which was lightest and it therefore had to go beside the valve to help obtain correct balance? I seem to recall it was initiated in the days when tyre manufacture was perhaps less consistent than nowadays and most tyres had a heavy and light spot which occurred during the manufacturing process? This placement could make quite a difference and I also recall many years ago having some tyres taken off of their rims and revolved half a turn and refitted to help balance? But I could just as easily be totally wrong again! Rich PS - for anyone reading, might I suggest that this approach from the master of diplomacy is a nicer way to question a posting? Link to comment Share on other sites More sharing options...
davenewellhome Posted October 9, 2007 Share Posted October 9, 2007 No problem with asking Richard. I don't honestly know which is correct as I was never fully trained in tyre fitting, I covered the basics at college but that was the best part of thirty years ago. I thought, from memory, that the red spot went diametrically opposite the valve but it could just as easily go adjacent to the valve. All I do know is not many tyre fitters seem to be aware of it (assuming I'm not talking complete b0110cks) as I've seen the red spot at a variety of positions around the rim. Dynamic wheel balancing is a two fold operation. One is to balance the wheel diametrically and secondly to balance the wheel inside to outside so I too am a little perplexed about the re-positioning of the weights. D. Link to comment Share on other sites More sharing options...
Guest starspirit Posted October 9, 2007 Share Posted October 9, 2007 Cheers Dave - confusion reigns eh? Given the education level and product knowledge base of the average tyre fitter (self employed local guys excepted - usually) I sometimes have to wonder why there are not more tyre related accidents. I don't recall seeing any coloured dots on any tyres of late so perhaps they come pre balanced and thus only the wheel needs balancing. But then I rarely need tyre nowadays as I change the car whenever the carpets need hoovering! But then again changing a tyre invariably means a re balance so that idea don't work either! I had a new tyre on the Verso recently and the guy said he could put all the balance weights on the inside of the rim rather than deface the front of my nice alloys for which I am truly grateful and the balance is fine right up to as quick as I am ever likely to go and then some. Link to comment Share on other sites More sharing options...
mark lambert Posted October 9, 2007 Share Posted October 9, 2007 i was a tyrefitter for 10 yrs, changed jobs not long ago. Years ago cars would always have their wheels balanced on the car with a little machine that would spin the wheel at a fairly high speed and would send the vibration through a little stand that was placed under the suspension, reason for doing it this way was because the off car balancer would only balance the wheel and tyre, wheras the on car balancer would also take into account the wheel trims. we had a new balance machine sent to us with the manufacturers expert to show us/me how to use the machine properly, he told me, the red spot should be next to the valve to give a better balance. These days wheels and tyres are much better made so are only balanced off the car, i'm sure most fitters aren't even told about the red spot because tyres are so good. Iff the weights are only placed on one side it is possible that vibrations will still be felt, so it is automatically done on both sides, with a little experience/thought a fitter will know to ask the customer if he minds having the weights showing on his wheels(alloys), some alloy wheels can be balanced on both sides without showing the weights, some can't. but one can always have the wheels just balanced on one side, the inside, but you may get a vibration! when balancing the wheel on the machine, the weights should be at the top of the wheel when the machine shows no weight needed. a little long winded i'm afraid. Link to comment Share on other sites More sharing options...
Guest starspirit Posted October 9, 2007 Share Posted October 9, 2007 Thanks for that mark, very informative, well balanced and not tiring to read. Being of a certain age I too recall the on car balancer used mainly on Fords with McPherson Strut suspensions they were such bu##ers to balance. Link to comment Share on other sites More sharing options...
davenewellhome Posted October 9, 2007 Share Posted October 9, 2007 Yes I too remember the on car balancer, it was what we used when I was doing my apprenticeship but we didn't fit tyres in our garage, only balanced them. D. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted October 13, 2007 Share Posted October 13, 2007 There is a large amount of tyre-related technical data on the Toyo(Australia) website, including the following about wheel-balancing: http://www.toyo.com.au/tech_info14.html This indicates that modern convention regarding tyre 'dot marking' (and wheel-rim marking) is more complex than might be expected. Having been a recent victim of the dreaded Ford Transit tyre-valve failure, I shall be having the original equipment (OE) valves replaced and this will involve the wheels being re-balanced. I checked my motorhome's wheels/tyres and their markings matched the information provided on the Toyo website. In the past, three of the tyres have needed to be removed from the wheels and subsequently be re-balanced, but the other two are still in the same position on the wheels as when the vehicle left the Ford factory. However, the relative positions of these tyres' 'dots', wheel-markings and tyre-valves appear to follow no obvious pattern. I contacted Michelin for advice and a further twist in the tale emerged. It appears that the position of markings on OE tyres (that's tyres supplied by a tyre manufacturer directly to a vehicle manufacturer for fitting in the latter's factory) may differ from the convention relating to markings on tyres destined for after-market fitment. I expressed some surprise at this, but the chap I spoke to confirmed this with his colleagues: he recalled that Rover (now defunct of course) had asked Michelin to mark their OE tyres differently from the norm. In view of the seemingly haphazard relationship of my Transit's tyres to its wheels in terms of their markings, it's a fair bet that (on Transits at least) Ford don't bother to match tyre to wheel prior to balancing. And, if this results in big hunks of lead clipped to the rims, then so what? - Transits are little lorries not luxury limousines. I notice that the Toyo website recommends that wheel-balancing should be carried out on a machine that uses a cone behind the wheel centre and a flange-plate on the front of the wheel/tyre assembly to locate the latter through the wheel stud holes. Most balancing machines I've encountered seem to use just a cone that locates the wheel through its central hole. This allows a wheel to be installed and removed very quickly from the machine and, most of the time, seems to work OK. However, when I had all five OE tyres replaced on my previous Transit-based Herald, the 'cone only' method was used for balancing and worryingly large balance-weights were needed. A quick trial on the motorway produced serious steering-wheel shake and a rapid return trip to the tyre-fitter. One of the wheels was re-fitted to the machine and proved to be badly out of balance. It was re-balanced but, before it could be put back on the motorhome, I asked the fitter to replace it on the machine and re-check it. Once again it was badly out of balance. At this point the boss was called in, who fitted a flange-plate to the machine. This took some time to do, but resulted in a reliable balance involving considerably smaller weights. It was explained that the problem was due to the holes in the wheels not being truly central, but it's far more plausible that the holes (being large) wouldn't centralise consistently on the cone. I was told that an automatically-adjusting flange-plate was available (the one used for the Herald's wheels required fiddling with spanners and plenty of expletives), but it was expensive and not a cost effective buy for small tyre-fitting firms. Anyway, the moral of this story is that, if really heavy balance weights are needed on your vehicle's wheels, then it may be the fault of the balancing machine rather than the wheel/tyre combination. (In the 1980s, when the tyres were changed on my first VW Golf Gti it proved extraordinarily difficult to balance its alloy wheels acceptably. The problem was that imbalance only showed up at speeds above 80mph and balancing the wheels off-car didn't cure it. I took the Golf to a tyre-fitting outlet who raised the front of the car on a pair of trolley-jacks and got me to sit in the car and 'drive' it with the front wheels off the ground while the balancing machine was shining a strobe-light at the rotating tyre. This was a very unnerving experience, with 100mph on the speedometer, the front wheels vibrating wildly and knowing how precariously the Golf was supported. Nevertheless it did work, but I was glad that I sold the car before the next tyre change became necessary!) I also came across the following website: http://www.counteractbalancing.com/ This technique of using 'balancing beads' is new to me, but, in principle, seems a whole lot simpler, tidier and more effective than attaching weights to the wheel-rim. Theoretically a better balance should be obtained as the whole rotating mass (including hub, brake-disk/drum, etc.) is being balanced not just the wheel/tyre assembly alone. Assuming it works as described, the only potential drawback I can envisage is that it probably precludes use of an anti-puncture tyre sealant. Link to comment Share on other sites More sharing options...
Guest Tracker Posted October 13, 2007 Share Posted October 13, 2007 My complements Derek on a very worthwhile and informative piece of research. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.