CISCO Posted May 17, 2006 Share Posted May 17, 2006 Last Thursday morning we set off for the Newbury Show and as the MH had not been used for a while, stopped off at the ATS tyre centre to check the tyre pressures. My chancellor noticed that they were having a promotion on Michelin tyres (up to 25% - until 27 May) I duly enquired and got a quote for 4 tyres. (215/75 16 XC Camping) Ordered the tyres and was told they would be waiting for us on our return from the show. Yesterday morning (Tuesday) had them fitted and their service was outstanding, many thanks to Tom who did the job. New tyres dated, on the outside wall 1406 (first week in April 2006) My old tyres (less than 30,000) were pre 2000 and their date was on the inside wall. The vehicle is a Laika 7r (3850): usually running at approx 3300. I run him at 65 front and 70 rear (air ride at 3 bar) (wheel torque at 133 lbft) The bill which included balance and environmental disposal of old tyres came to £441.31 and I was given a Re-Torque Tag to remind me to return after approx 50 miles. Thanks also to all the posts from everyone about tyres/pressures. They have been most useful. As a foot note Tom (ATS) gave and showed me some excellent tips should I ever have to change a wheel , particularly the rear ones. (these tips were pertinent to our body work/construction) First use of ATS and for the service I received will not be the last. (p.s. I have no conection with ATS other than a very satisfied customer,also, I did ask the ATS manager if he minded I post this) Link to comment Share on other sites More sharing options...
Norma Posted May 17, 2006 Share Posted May 17, 2006 Wow - someone has found hen's teeth. The XC tyres do exist for buying. Link to comment Share on other sites More sharing options...
Wingpete Posted May 18, 2006 Share Posted May 18, 2006 Very interesting ! My Laika/Fiat 2.8 jtd, (for 3.8 tons) has 16 inch wheels and Fiat manual calls for 5.5 bar, or 80 psi in old money. Anone have thoughts on variations of pressures indicated in these relevant postings? Link to comment Share on other sites More sharing options...
JohnP Posted May 18, 2006 Share Posted May 18, 2006 If you have Michelin tyres I suggest that you contact their Technical Dept. for advice on pressures. They will need to know the tyre specification and the front and rear axle loadings when your MH is in use. From my experience they tend to suggest a lower reading than the vehicle manufacturers. Their contact number is elsewhere on this forum Link to comment Share on other sites More sharing options...
Derek Uzzell Posted May 18, 2006 Share Posted May 18, 2006 My recollection of discussion with the Knaus Owners Club on much the same subject was that the Laika Owners Club had taken this up with the Laika factory and had been given (downwardsly) revised inflation-pressure figues for 'normally loaded' Fiat-based Laika motorhomes. Link to comment Share on other sites More sharing options...
CISCO Posted May 18, 2006 Author Share Posted May 18, 2006 As with many other people, I suspect, the question of tyre pressure has cropped up. Initially we ran our MH at 80 psi front and rear – that’s how it came and for the first couple of years did not think, understand or whatever consider to change it. It came with what appears to be the ubiquitous Michelin 215/75 16 XC’s and that’s what I have replaced them with. (Due to age not mileage or condition) This morning I spoke to Michelin (Andy) at: Mitchelin Tyre PLC, Stoke-on-Trent. Tel: 01782 402000 gave the details of the vehicle, the tyres and the axle weights. I had previously taken the MH to the weighbridge at the Trading Standards Service Centre here in Taunton. They supplied me with a Certificate of Accuracy stating: Under the Weights and Measures Act 1985 – Section 74 (4) Gross: 3550kg Front axle: 1610kg Rear axle: 1935kg (note: This included 50% fresh water, full fuel tank, all stuff for 4 week trip and 50cc scooter mounted on wind out rear rack) The man at Mitchelin (Andy) took the details and said he would call me back in 10-15 minutes. This he duly did and gave me the following recommendation: Front axle 1610 = 51 psi and Rear axle 1935 = 56 psi. Oh ! – He sensed that I was a little uncomfortable with how low these figures sounded, considering my limited experience, I have over the last 6 years travelled approx 25K and never had a tyre pressure less than 65 psi. What’s more, never felt any undue problems or had any failures. He said he would get someone to call me. (I requested after 4 pm) At 4:10 pm a call from Michelin (Mark). Not that I can remember everything he or I said but we had a general discussion about this tyre, our vehicle and my expectations of usage. We tried to look at as much variety of use as possible. Always bearing in mind those exceptional circumstances (one off heavy load ! etc) which would attract a rethink on psi. From the telephone advice now provided by Mitchelin it was understood by me that the front axle should be no lower than 55 psi and the rear axle no lower than 60 psi. I feel more comfortable/reassured following my discussion with Mitchelin and I would recommend anyone who has concern to contact them and discuss their circumstances with them. (Thanks to Andy and Mark) Although there are circumstances which you may elect to use 80 psi (these appear to be the exception rather than the rule - speak to Michelin) I personally do not expect ever to use 80 psi again. (Possibly if the vehicle was standing for an extended period) Other than that I shall use the guide of no less than 55 psi – front and no less than 60 psi – rear. This tyre’s versatility allows higher psi levels to be used but then you move into the domain (Mitchelin’s words) of what’s best and what’s comfortable for you. I have now chosen for a trial period to run our MH at 60 psi front and 65 psi rear. (this is 5 psi less than my own original figures but 5 psi above the figures discussed with Michelin) My reasoning for adding the 5 psi is predominately a comfort factor one. My inner self is looking at things like variety of journeys, hopefully catering for modest weight changes and motorway use. Should I (if I’m able) feel or sense the ride too soft or whatever I shall return to 65 front and 70 rear. Hope this is of some use to others, regards to all – CISCO. p.s. some things in life get harder whereas this one appears to have got softer ! Link to comment Share on other sites More sharing options...
Wingpete Posted May 19, 2006 Share Posted May 19, 2006 What is the likely downside of running at 80 psi ? The Fiat book has a long list of variations for the Ducato's Link to comment Share on other sites More sharing options...
Derek Uzzell Posted May 19, 2006 Share Posted May 19, 2006 The effects of running tyres at higher than necessary pressures are totally predictable - reduced tyre longevity, reduced grip (hence reduced road-holding and braking performance) and increased wear-and-tear on the vehicle and its occupants. There is absolutely no advantage choosing to inflate a Michelin XC Camping tyre to 80psi just because it is capable of tolerating that pressure. If (say) 60psi is the pressure recommended by Michelin for a measured axle load, then that's the pressure to use. Of course, if like CISCO, one wants to play around with tyre pressures on a 'feel factor' basis (and I confess to having that tendency myself) then that's something else entirely. Link to comment Share on other sites More sharing options...
Wingpete Posted May 22, 2006 Share Posted May 22, 2006 Laika Advice. I asked the question of tyre pressures, and the answer is, it depends on loads carried, speed of vehicle, road conditions, (wet or dry) weather variations (hot or cold temps alter pressure) and surfaces of road transversed. So, work it for yourself, as everyone has a getout clause if it goes wrong ! >:-( Link to comment Share on other sites More sharing options...
passionwagon Posted May 22, 2006 Share Posted May 22, 2006 8-) For Alko chassis conversions to max 3850kg ,the pressure is 5.5 bar. This is because motorhomes are invariably at or close to their max legal weight. Remember if your pressures are found to be incorrect by the insurers engineers or police at the time of a serious accident then no insurance. Personally I prefer to run against the printed Alko information. Incidentally remember to have steel valves fitted-rubber ones are unsafe. Pip pip ;-) Link to comment Share on other sites More sharing options...
Mike Chapman Posted May 22, 2006 Share Posted May 22, 2006 Hello passionwagon, The pressure for tyres, no matter what the chassis type, is related to the tyre make and model and the axle weight. For instance if your vehicle had Michelin Agilis 81 tyres fitted 5.5 bar or 80 psi is way above the maximum allowed pressure for this tyre and is at the absolute maximum for the Michelin XC Camping. Under Construction and Use regulations the tyre must be so inflated as to make it fit for the use to which the motor vehicle is being put. Regards, Mike :-D Link to comment Share on other sites More sharing options...
passionwagon Posted May 23, 2006 Share Posted May 23, 2006 :-S Hello Mike. Interesting to see your note but my information has been confirmed by Alko, FIAT Italia and Michelin. :-S Link to comment Share on other sites More sharing options...
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