Guest Tracker Posted September 25, 2008 Share Posted September 25, 2008 Before buying a van with either an Alko chassis or the new Fiat long wheelbase motor home chassis please be aware of the low ground clearance that these chassis have. Combined with the 160" wheelbase the mere 6.5" ground clearance on many vans means that you will not be able to get the vehicle over a pavement and into many sloping drives where the gradient exceeds 1:7 (14% in new terminology) The latest Swift vans in particular have a very low slung water tank where the bung is the lowest point in the van and is almost at midpoint in the wheelbase - the most vulnerable point for grounding and there are also implications for site ramps, sleeping policemen etc., and covering rough ground both on and off sites. Link to comment Share on other sites More sharing options...
rupert123 Posted September 25, 2008 Share Posted September 25, 2008 Tracker - 2008-09-25 11:38 AM Before buying a van with either an Alko chassis or the new Fiat long wheelbase motor home chassis please be aware of the low ground clearance that these chassis have. Combined with the 160" wheelbase the mere 6.5" ground clearance on many vans means that you will not be able to get the vehicle over a pavement and into many sloping drives where the gradient exceeds 1:7 (14% in new terminology) The latest Swift vans in particular have a very low slung water tank where the bung is the lowest point in the van and is almost at midpoint in the wheelbase - the most vulnerable point for grounding and there are also implications for site ramps, sleeping policemen etc., and covering rough ground both on and off sites. Tracker I have a fairly new Swift and one of the water tanks, the waste, is indeed low. The fresh water one is fairly tucked away though, however lowest point is the rear axle. I have never grouded it and that includes a pretty steep ferry ramp onto the Orkney ferry this year. One of the loaders was looking under all m/h's to check this very point. I have noticed a lot of new vans that are now very low but just one more thing you have to be aware of. Link to comment Share on other sites More sharing options...
Guest Tracker Posted September 25, 2008 Share Posted September 25, 2008 A low axle is not in itself a problem because due to the wheels being on the axle itself you will never have less ground clearance than the axle. The problem of grounding arises midway between axles when front and rear wheels are on different levels - eg front on the level and rear on a down gradient - like many sloping driveways - when whatever is between the axles clouts the ground. I'm not knocking the design (although I could be tempted to say something like another triumph of form over function!) and I am not saying don't buy one - I am just saying be aware of it! Link to comment Share on other sites More sharing options...
Derek Uzzell Posted September 26, 2008 Share Posted September 26, 2008 Just for the record... Coachbuilt motorhomes constructed on the latest Fiat X250 design will (in Fiat-speak) have "Leisure-time chassis-cab" or "Special leisure-time chassis-cab" bases, or an Al-Ko-produced from-cab-backwards replacement rear chassis. On a like-for-like basis (same wheels, tyres, springs) there is no difference in ground clearance between an 'ordinary' Leisure-time chassis-cab and a Special leisure-time equivalent. The latter has a wider rear track and its design will facilitate positioning of water/waste tanks, but the distance from the underside of each chassis-type to the ground will be the same. Fiat's Ducato Motorhome UK advertising brochure does refer to "reduced ground clearance making for easier access to the habitation area" being a feature of the Special Leisure-time chassis, but this is misleading. The main dimensional difference between the two chassis types is that the depth of the rails and cross-members making up the 'ladder' of the ordinary chassis is far greater than that of the Special chassis. If you study the two chassis types, you'll see that the cross-sectional profile of the rails/cross-members of the ordinary chassis can be considered to be 2-part, with a deep upper section joined to a shallower lower one. However, for the Special chassis, the upper section of each rail/chassis-member has been dispensed with. This saves a good deal of weight and significantly reduces the distance from the TOP surface of the chassis to the ground - thus allowing the motorhome converter to fit a lower floor - but, as the position where the lower 'section' of each chassis-type attaches to the cab is the same, the ground clearance below the chassis is also the same. (To my eyes the Special chassis looks startlingly flimsy compared to the ordinary version, but I presume sufficient stiffness is regained once the motorhome's coachbuilt bodywork has been grafted on.) The replacement Al-Ko chassis is attached to the Fiat cab via lowered 'brackets' (and, of course, has a completely different rear suspension) and this is bound to reduce ground clearance comparatively. As Tracker warns, the likelihood of ground clearance problems occurring will increase as motorcaravan manufacturers exploit the potential of these chassis to offer sleek motorhomes with low floors, with space-consuming service items (like water/waste tanks) slung beneath. A Fiat-based motorhome built on a current long-wheelbase non-Maxi chassis will inevitably be vulnerable to grounding part way along its length and, looking at some present designs, it seems just a matter of time before there's an letter in MMM from an outraged owner whose 'van ends up beached on the summit of a steep ferry boarding ramp. Link to comment Share on other sites More sharing options...
Brock Posted September 26, 2008 Share Posted September 26, 2008 My 05 plated Hymer 544 grounded when going over a kerb at an angle (central external locker on passenger side) and the rear end of the chassis grounds when I turn right out of the local Shell garage (I now turn left!). On the plus side, when reversing I grounded the chassis on a low snow drift which I didn't see (no reversing camera) and the noise was so loud that I stopped and thus avoided any damage to the bodywork. The low height also means it' difficult get under the van unless it is jacked up or on ramps. The rear extension has also started to rust although I managed to slap on some hammerite having removed the surface rust. Rest of the chassis is fine. The low chassis has benefits although I am not convinced they outweigh the disadvantages. Link to comment Share on other sites More sharing options...
Guest Tracker Posted September 26, 2008 Share Posted September 26, 2008 The low chassis is not too bad in itself but the problem compounds very considerably when the standard wheelbase of around 3000 cm or so is extended to the long wheelbase of about 388 cm or even 4035 cm. Link to comment Share on other sites More sharing options...
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