BigKev258 Posted June 21, 2016 Share Posted June 21, 2016 Hi everyone, newby here. We recently bought a 'smiley face' transit MH, it has 'Airide' suspension but I have no idea what PSI to use ? Currently whoever sits in the rear while travelling has a roller coaster ride, frequently leaving the seat completely Link to comment Share on other sites More sharing options...
witzend Posted June 21, 2016 Share Posted June 21, 2016 Hi I've been looking into air suspension and I think you'll need to experiment with it to find the pressure to suit you don't let it right down though. There's another thread on here here's a quote from there. It is only the basic system with two independent Schrader valves for inflation and I normally check it before every trip and it usually requires 2 or 3 psi to get back to my optimum 40 psi. http://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/Ducato-X250-Air-Suspension/41978/ Link to comment Share on other sites More sharing options...
Keithl Posted June 21, 2016 Share Posted June 21, 2016 Hi, Three questions for you... 1. What year is your 'Smiley face' Transit? 2. What pressure are you currently using in your Airride system? 3. What tyre pressures are you running? I have the Dunlop system fitted to our Sprinter and find 40 psi gives a decent ride but I think you will find tyre pressures have more to do with your roller coaster ride than your air suspension. Keith. Link to comment Share on other sites More sharing options...
phalange Posted June 21, 2016 Share Posted June 21, 2016 i had air ride on my last Hymer with a fiat ducato chassis,max pessure was 7 bar, i used to inflate it to anywhere between 4 and 5 bar. Less than 4 and it bounced more than 5 it was too harsh. But like Witzend has said you will need to experiment. Best thing i ever fitted to the van tho. Link to comment Share on other sites More sharing options...
Guest pelmetman Posted June 21, 2016 Share Posted June 21, 2016 In our MK 3 coachbuilt transit we have 1 bar in the offside and 2 bar in the nearside, to counteract a slight lean to Port :D ....... One curiosity we discovered the other day when trying to top them up using a service station air hose......It wouldn't inflate, and actually deflated the airbags *-) ........ended up using a foot pump :-S .... Link to comment Share on other sites More sharing options...
thebishbus Posted June 21, 2016 Share Posted June 21, 2016 With my Hymer, ( double leaf springs ) I find about 25 lbs / 28 lbs to work . Above 30 lbs is to hard. Brian B. Link to comment Share on other sites More sharing options...
david lloyd Posted June 21, 2016 Share Posted June 21, 2016 As others have said, your harsh ride at the rear may be as much to do with tyre pressures. Many dealers and tyre fitters use the base vehicle tyre pressures in the handbook and these can be as high as 80 psi. I have just had air suspension fitted to my coachbuilt as part of the requirement for replating to 3850kgs GVW. The rear tyre pressures given to me by Continental (for a rear axle at 2240kgs and fitted with 225/70R15 tyres) is 65.2 psi. The air suspension is set at 3 bar and so far this gives a comfortable ride. I am going to experiment with a slightly lower pressure in the airbags though as I would like to lower the ride height a little more. David Link to comment Share on other sites More sharing options...
Colin Leake Posted June 22, 2016 Share Posted June 22, 2016 For what it's worth 2 bar in our AutoSleeper van conversion with two leaf springs works well for us. As someone else has said the whole point of it being adjustable is to enable you to experiment to find the best setting. Velcro on the passengers pants may help keep them in place! Link to comment Share on other sites More sharing options...
davidmac Posted June 22, 2016 Share Posted June 22, 2016 Hi, I would suggest a different approach to pressure settings. 1st empty the motorhome 2nd deflate airbags 3rd measure the height to the top of the rear wheel arch from the ground on both sides and note 4th load motorhome for a trip 5th inflate airbags to lift suspension to height previously noted The aim is to get the ride height to its designed level.If you infate the airbags too much you lift the centre of gravity therefore getting more roll when cornering and passing/being passed by other vechicals. Regards David Link to comment Share on other sites More sharing options...
witzend Posted June 23, 2016 Share Posted June 23, 2016 If you deflated the air bags would the suspension compress further. With the ones I've looked at I think not but aren't sure Link to comment Share on other sites More sharing options...
david lloyd Posted June 23, 2016 Share Posted June 23, 2016 davidmac - 2016-06-22 4:53 PM Hi, I would suggest a different approach to pressure settings. 1st empty the motorhome 2nd deflate airbags 3rd measure the height to the top of the rear wheel arch from the ground on both sides and note 4th load motorhome for a trip 5th inflate airbags to lift suspension to height previously noted The aim is to get the ride height to its designed level.If you infate the airbags too much you lift the centre of gravity therefore getting more roll when cornering and passing/being passed by other vechicals. Regards David Took your advice David - cleared everything out the garage and deflated the suspension (although I only took it down to 0.5 bar as this is the recommended minimum pressure) did the measurement, put everything back including some extra representing the other stuff we take that would put some weight in the rear and measured again. In the end I have inflated it to 2.5 bar which is less than I had it at (3 bar) but the ride height is slightly higher than when the bags were deflated by about 0.5 cm. So, I am going to try it for the next time out to see how it is and may do the exercise again before we set off on our winter trip to Spain. David Link to comment Share on other sites More sharing options...
Brian Kirby Posted June 23, 2016 Share Posted June 23, 2016 davidmac - 2016-06-22 4:53 PM Hi, I would suggest a different approach to pressure settings. 1st empty the motorhome 2nd deflate airbags 3rd measure the height to the top of the rear wheel arch from the ground on both sides and note 4th load motorhome for a trip 5th inflate airbags to lift suspension to height previously noted The aim is to get the ride height to its designed level.If you infate the airbags too much you lift the centre of gravity therefore getting more roll when cornering and passing/being passed by other vechicals. Regards David Seconded! This is exactly the approach I used on our Hobby Van, and the results exceeded my expectations - which were merely to stop the tail grounding on abrupt level changes. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted June 25, 2016 Share Posted June 25, 2016 BigKev258 - 2016-06-21 2:11 PM Hi everyone, newby here. We recently bought a 'smiley face' transit MH, it has 'Airide' suspension but I have no idea what PSI to use ? Currently whoever sits in the rear while travelling has a roller coaster ride, frequently leaving the seat completely Ford Transits made from around 1995 to 2000 are normally referred as Transit Mk 5s and are recognisable by their ’smiley face’ radiator grille. All Mk 5s had rear-wheel drive (or occasionally four-wheel drive) and the diesel engine was 2.5litre capacity. However there were major specification differences and Transit Mk 5-based motorhomes could range from relatively small, lightish panel-van conversions to large quite heavy coachbuilt designs with a twinned-wheel rear axle. Consequently it would be helpful if you provided your motorhome’s make, model and year of manufacture as the most suitable tyre (and Airide) pressures will depend on the vehicle’s specification and the tyres fitted to it. Transit Mk 5s were generally said to have a softish ride quality and (as Keith suggests earlier) a really harsh rear-end ride suggests overly high tyre pressures and/or an overly high pressure in the Airide units. (If you want a finger-in-the-wind guesstimate, if your motorhome has 225/70 R15C tyres, pressures of around 41psi(front) and 52psi(rear) should be about right, with the Airide units’ pressure no higher than 30psi.) Link to comment Share on other sites More sharing options...
BigKev258 Posted June 27, 2016 Author Share Posted June 27, 2016 UPDATE !! Thanks everyone who has replied. The van is on a 'N' reg (95/96) The situation was, the rear tyres are 225/70x15, they had 62lbs in them and surprisingly the airide had 7lbs in it. I have now done 52lbs in rear tyres and 30lbs in airide, as a starting place. Link to comment Share on other sites More sharing options...
witzend Posted June 27, 2016 Share Posted June 27, 2016 What do the tyres look like with 52 psi I run mine same size at 75 psi any less and they look flat. Running flat can damage tyres Link to comment Share on other sites More sharing options...
Keithl Posted June 27, 2016 Share Posted June 27, 2016 225/70 R15 tyres at 52 psi can support an axle weight of well over 1,800 kg so I doubt very much if they are overloaded BUT it would be wise to weigh the MH and get individual axle weights to confirm. You can get a good idea of pressure versus axle load from the TyreSafe website MH booklet which you can download from here... Link. Keith. PS Ordinary 'White Van' C rated tyres CANNOT be inflated to 75 psi, you must have 'Camper' or CP rated tyres to run at this pressure! Link to comment Share on other sites More sharing options...
Derek Uzzell Posted June 28, 2016 Share Posted June 28, 2016 Mid-1990s coachbuilt motorhomes based on Transit Mk 5 ‘ladder’ chassis with single-wheel rear axle were normally fitted as original equipment with Michelin 225/70 R15C 109R 6PR tyres and Michelin’s pressure recommendations for these were (as I said earlier) 41psi(front) and 52psi(rear). This was the specification of the Michelin “XCA” tyres originally fitted to my 1996-built Transit-based Herald Templar and the 41/52 pressures were what I used with those tyres. I replaced the original tyres with same size Michelin Agilis 81 tyres that were 8PR-rated with a load-index of 112 and (after discussion with Michelin) inflated these to 41psi(front) and 60psi(rear). A load-index of 109 equates to a maximum axle-load of 2060kg, and a load-index of 112 equates to 2240kg. While the ‘norm’ was for Transit Mk 5-based coachbuilt motorhomes with 225/70 R15 tyres to have “C"-marked (‘white van’) tyres as original equipment, in those days Michelin were producing the "XC Camping” pattern in 225/70 R15 size and some Transit motorhomes were equipped with these. XC Camping targeted the motorhome market and (when fitted to Fiat Ducatos) were custumarily inflated to 80psi. Without knowing the make and model of BigKev258’s motorhomel (or the make and exact specification of the tyres it now wears) it’s not easy to provide specific advice. As Keith says, weighing the vehicle would be useful. I doubt if it much matters whether the rear tyres are inflated to 52psi or 62psi as far as the ride is concerned, but it’s tempting to think that the Airide units were fitted for a good reason and this was often because the stiffness of the rear springs had begun to deteriorate. 7psi in the Airide units is definitely too low and 30psi seems like a reasonable pressure to begin experimenting with. Link to comment Share on other sites More sharing options...
davidmac Posted June 28, 2016 Share Posted June 28, 2016 Brian Kirby - 2016-06-23 5:37 PM davidmac - 2016-06-22 4:53 PM Hi, I would suggest a different approach to pressure settings. 1st empty the motorhome 2nd deflate airbags 3rd measure the height to the top of the rear wheel arch from the ground on both sides and note 4th load motorhome for a trip 5th inflate airbags to lift suspension to height previously noted The aim is to get the ride height to its designed level.If you infate the airbags too much you lift the centre of gravity therefore getting more roll when cornering and passing/being passed by other vechicals. Regards David Seconded! This is exactly the approach I used on our Hobby Van, and the results exceeded my expectations - which were merely to stop the tail grounding on abrupt level changes. HI I think it was Brian that put me onto this method Regards David Link to comment Share on other sites More sharing options...
BigKev258 Posted June 29, 2016 Author Share Posted June 29, 2016 The M/H is a '96 Ford Transit Herald 'Valencia', it has a max weight of 3300kg with unladen weight of 2850kg, the current tyres fitted are 225/70x15C Link to comment Share on other sites More sharing options...
Derek Uzzell Posted June 29, 2016 Share Posted June 29, 2016 I have a copy of a MMM magazine October 1995 review (by Jonathan Lloyd) of a Herald Valencia. The maximum authorised overall weight quoted in the review was 3300kg, with an unladen weight of 2850kg (with a weighbridge tolerance of 20kg). Those figures tally with what you’ve said. In those days Herald was quoting their motorhomes’ unladen weight with no allowance for water, gas, passengers, baggage, accessories, etc. and, when I weighed my own (shorter) Herald Templar in normal loaded trim (with a single passenger and no heavy extras), although its axle loadings were well under the maximum authorised limits its overall weight was approaching 3300kg. I recall mentioning this to an owner of one of the longer Aragon/Valencia 3300kg models who told me that he had fitted a large awning, a tow-bar and additional leisure batteries. I asked what the vehicle weighed and was told that he dare not weigh the motorhome, preferring to remain in blissful ignorance! I was in the Herald Owners Club and it was evident from other members’ comments that it was quite common for ‘semi-air assistance’ (usually “Airride” units back then) to be added to the rear suspension of longer Transit-based Herald models to combat cornering sway, improve stability in high wind conditions (my Templar could make me very anxious in strong cross-winds) and reduce rear-end sag. In your original posting you said "Currently whoever sits in the rear while travelling has a roller coaster ride, frequently leaving the seat completely”. The Valencia design comprised the kitchen and shower compartment directly behind the cab area and a large wrap-around U-lounge at the back that could be converted into a double bed or two singles. But (to the best of my knowledge) Herald fitted no seat-belts to the U-lounge seating as standard or offered them as an option. Essentially, a Valencia was designed to be driven with just two people occupying the cab seats. As a Valencia’s U-lounge is behind the rear axle it’s far from the ideal place to carry passengers and, if your passengers are being carried in the U-lounge facing forwards with their backs next to the Valencia’s rear wall, I’m not in the least surprised that they are experiencing a bouncy roller-coaster ride. Playing about with tyre and the Airride-unit pressures might help, but if passengers are carried right at the rear of a Valencia it’s pretty much inevitable that they will experience a lot of up-and-down movement. Link to comment Share on other sites More sharing options...
BigKev258 Posted June 29, 2016 Author Share Posted June 29, 2016 Derek Uzzell - 2016-06-29 12:15 PM I have a copy of a MMM magazine October 1995 review (by Jonathan Lloyd) of a Herald Valencia. The maximum authorised overall weight quoted in the review was 3300kg, with an unladen weight of 2850kg (with a weighbridge tolerance of 20kg). Those figures tally with what you’ve said. In those days Herald was quoting their motorhomes’ unladen weight with no allowance for water, gas, passengers, baggage, accessories, etc. and, when I weighed my own (shorter) Herald Templar in normal loaded trim (with a single passenger and no heavy extras), although its axle loadings were well under the maximum authorised limits its overall weight was approaching 3300kg. I recall mentioning this to an owner of one of the longer Aragon/Valencia 3300kg models who told me that he had fitted a large awning, a tow-bar and additional leisure batteries. I asked what the vehicle weighed and was told that he dare not weigh the motorhome, preferring to remain in blissful ignorance! I was in the Herald Owners Club and it was evident from other members’ comments that it was quite common for ‘semi-air assistance’ (usually “Airride” units back then) to be added to the rear suspension of longer Transit-based Herald models to combat cornering sway, improve stability in high wind conditions (my Templar could make me very anxious in strong cross-winds) and reduce rear-end sag. In your original posting you said "Currently whoever sits in the rear while travelling has a roller coaster ride, frequently leaving the seat completely”. The Valencia design comprised the kitchen and shower compartment directly behind the cab area and a large wrap-around U-lounge at the back that could be converted into a double bed or two singles. But (to the best of my knowledge) Herald fitted no seat-belts to the U-lounge seating as standard or offered them as an option. Essentially, a Valencia was designed to be driven with just two people occupying the cab seats. As a Valencia’s U-lounge is behind the rear axle it’s far from the ideal place to carry passengers and, if your passengers are being carried in the U-lounge facing forwards with their backs next to the Valencia’s rear wall, I’m not in the least surprised that they are experiencing a bouncy roller-coaster ride. Playing about with tyre and the Airride-unit pressures might help, but if passengers are carried right at the rear of a Valencia it’s pretty much invitable that they will experience a lot of up-and-down movement. It has had rear seat belts fitted. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted June 29, 2016 Share Posted June 29, 2016 BigKev258 - 2016-06-29 4:00 PM It has had rear seat belts fitted. Suggest you check very carefully how this has been done. Adding seat-belts to older motorhomes was commonplace at one time, with no real regulations covering how this should be carried out. Besides the uncomfortable experience a passenger is likely to have sitting at the very rear of a motorhome that has a significant rear overhang, there’s often not much strength in rear seats not originally designed to be genuine ‘travel seating’ and to have seat-belts fitted, nor in the wall behind and the floor beneath the seats. Fine if a very sturdy reinforcing structure has been fitted to your Valencia which the belts (presumably just lap-belts) attach to; not so great for passenger safety otherwise. Link to comment Share on other sites More sharing options...
david lloyd Posted June 29, 2016 Share Posted June 29, 2016 Derek Uzzell - 2016-06-29 5:23 PM BigKev258 - 2016-06-29 4:00 PM It has had rear seat belts fitted. Suggest you check very carefully how this has been done. Adding seat-belts to older motorhomes was commonplace at one time, with no real regulations covering how this should be carried out. Besides the uncomfortable experience a passenger is likely to have sitting at the very rear of a motorhome that has a significant rear overhang, there’s often not much strength in rear seats not originally designed to be genuine ‘travel seating’ and to have seat-belts fitted, nor in the wall behind and the floor beneath the seats. Fine if a very sturdy reinforcing structure has been fitted to your Valencia which the belts (presumably just lap-belts) attach to; not so great for passenger safety otherwise. And lap belts, in the event of an accident, cause significant abdominal injuries with very little protection offered - I would certainly think very carefully about their use in a rear lounge Motorhome. David Link to comment Share on other sites More sharing options...
Brian Kirby Posted June 30, 2016 Share Posted June 30, 2016 david lloyd - 2016-06-29 8:05 PM Derek Uzzell - 2016-06-29 5:23 PM BigKev258 - 2016-06-29 4:00 PM It has had rear seat belts fitted. Suggest you check very carefully how this has been done. Adding seat-belts to older motorhomes was commonplace at one time, with no real regulations covering how this should be carried out. Besides the uncomfortable experience a passenger is likely to have sitting at the very rear of a motorhome that has a significant rear overhang, there’s often not much strength in rear seats not originally designed to be genuine ‘travel seating’ and to have seat-belts fitted, nor in the wall behind and the floor beneath the seats. Fine if a very sturdy reinforcing structure has been fitted to your Valencia which the belts (presumably just lap-belts) attach to; not so great for passenger safety otherwise. And lap belts, in the event of an accident, cause significant abdominal injuries with very little protection offered - I would certainly think very carefully about their use in a rear lounge Motorhome. David I agree with both the above. How long have you had the van, and did you buy from a dealer? I would also ask, have you taken it to a weighbridge and weighed it fully laden (as in with driver, all passengers and everything else on board) and checked its maximum weight against its MAM, but more importantly based on everything else I have read in this thread, the load on the rear axle compared to its maximum permissible load? I'm beginning to fear, that with passengers seated right at the rear of the vehicle and substantially behind the rear axle, that axle is at considerable risk of overload. If that is the case, it would go some way to explaining the heavy pitching the rear seat passenger/s experience. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted June 30, 2016 Share Posted June 30, 2016 This 2008 forum thread discussed Ford Transit tyre pressures and axle loadings. http://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/Tyre-Pressure/13177/ The live rear axle and rear suspension of a 1996-built Herald Valencia are substantial, with twin leaf springs and an anti-sway bar. In 1998 I quoted maximum authorised axle loadings for my Herald Templar as 1600kg(front axle) and 2000kg(rear axle) and it’s almost certainly the case that Kev’s Valencia’s axle loadings will be the same. (This could easily be confirmed by Kev checking his motorhome’s VIN-plate figures.) In 2008 (referring to my Herald Templar) I said "Weighing my Herald also proved that, although it would have been virtually impossible to exceed its maximum permitted axle-loads, it wasn't that difficult to approach its 3300kg maximum permitted overall weight when the motorhome was full to the brim with fuel, water, passengers, luggage, etc.” A Valencia is 6.32m long. Although this is more than a Templar’s 5.9m length, a Valencia’s rear overhang is nothing like as extreme as is often the case nowadays. Consequently - unless a Valencia owner had a team of sumo wrestlers sitting in the U-lounge or was carrying gold bullion beneath the rear seats - the risk of rear-axle overloading is minimal. Kev’s passengers are being bounced because of where they are seated and this would predictably occur in any motorhome that has passenger seating well behind the vehicle’s rear axle. It would be worth weighing the Valencia in ’normal use’ state, and worth experimenting with tyre and Airride-unit inflation pressure, but none of those measures is going to alter the fact that Kev’s passengers are seated where vertical movement is bound to happen when the motorhome is being driven. Link to comment Share on other sites More sharing options...
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