Design Advice - Length versus Height

[S2DM]

We are in final stage discussion with a builder, but are still stuck on whether to do a cab-over design which would leave us taller but shorter length-wise, or a non cab over that would extend out the back, leaving us short height-wise, but long.

Either design would have a hard sided lifting box, similar to GXV Pangea LT or an XP camper.

Our base vehicle is a unimog 1300. If we did the cab over design, we would be around 11'6" tall and 18 feet long. If we did the non cab over design, we would be around 10 feet tall, but 22 feet long.

The non cab over is easier to design. We arent planning on container-ing either solution, though both boxes would be composite and easy to remove and container separately if we had to.

My main interest is south of the border, which design will be easier to drive and navigate, I.E. which will leave us feeling as nimble as possible in terms of traveling through small towns and back roads, and narrow paths out to the beach. The other consideration is that we have a cab lift on our truck, allowing amazing access to the engine and tranny in case of need for repair. If we did the cab over, I would probably either add camper jacks, or a hydraulic at the front to lift that edge enough to allow us clearance to lift the cab.

-S

 

[Haf-E]

I would just go with a cab mounted storage rack instead of the overcab design- the added space over the cab can be hard to use effectively.

Being able to tilt the cab without removing the box would be important in my opinion.

 

[S2DM]

We'd planned on putting the bed in the cab over area, similar to an XP camper. With the lifting top, we'd have about 3 feet of useable height above the mattress.
In terms of the cab tilt, I'd ideally wanted to just fit two hydraulic cylinders on the two front edges, and essentially "tip" the front edge of the box up in cases of needing to use the cab lift. But it would be a bit of work to release the mounting bolts and tip it for sure.

 

[Joe917]

I would go non-cab-over. The extra height is far more restrictive than length. So far as being nimble that's all about wheelbase which will be the same. Our MB917 is 26 feet long but turns on a dime.
Making it more inconvenient to access the engine is always a bad idea, it becomes easier to justify delaying routine maintenance and inspections. If you go cab-over I think you need to keep cab tilt as easy as possible.
Cheers.

 

[grizzlyj]

Hiya

We have a cabover on a U1700, 3250mm wheelbase.

As already said, since you've already fixed the wheelbase I don't think a bigger rear overhang will affect nimbleness. The floor is already a long way up so I doubt going longer will affect the departure angle enough to matter either. If you stick with the Mog three point linkage I wouldn't think you can just unbolt the front (and middle) and jack the camper up. A Mog chassis flexes a great deal and trying anything other than a three point linkage may not work as well as on other (straight chassis) trucks?

Everybody says you must not have a cabover due to engine access considerations. I disagree. Considering the floor or the overcab bed can/will be essentially one piece of plywood when constructed, you can fix it in such a way to be easily removable. The front wall also, make it unboltable and the cab can swing up and between the camper sidewalls as ours can do. Filters, oil and belts are accessed from the front so it would have to be an abnormal problem forcing a cabtilt rather than regular maintenance. Do you have the chassis mounted jack to tilt the cab?

Our camper is now 3.9m tall on 395 85 R20 XZLs and it has meant we can't go some places due to low trees or bridges. Not every country seems to have accurate maps showing height clearances! There is a photo somewhere of Stephen Stewart holding an overhead power cable up out of the way with a piece of wood to let his Mog roll under in S America. We carry a collapsible fishing rod in the cab cut to the correct length so we can see if we will fit rather than driving very slowly and waiting for the crunch! Whatever you drive you won't fit someplaces you may end up wanting to go, but with a good driving position, easily seen and positioned sides and corners, (almost!) no concerns about pulling up onto the verge, etc etc, then a Mog is a good vehicle to try to squeeze where others may not want to try. A second set of lights aimed up was a good addition for illuminating oncoming overhanging branches too high for the headlights.

Of course the more you can keep things small the less of a problem you may have when driving. But, if we had a lower box forcing a dinette/bed only for the two of us we may not have got on as well for the time we lived in it. Bedroom/lounge/kitchen/bathroom are separate enough to get out of each others hair if the weather is bad and navigation or something stupid means we've not got on that day

There will be a fair degree of side to side rocking that just results from tall tyres and suspension, the undamped camper three point linkage to chassis, and a tall body that takes a little getting used to and makes you slow down if you haven't already! http://www.youtube.com/watch?v=tBcVeq-IAZk Working gears and an exhaust brake are great at controlling speed!

My wife has back problems resulting in us ending up with Froli bed springs and a thicker mattress than when we started. We also don't have any under bed insulation or heating, so there is sometimes condensation under the mattress. Adding insulation would be good, but the above has already eaten into the free space above the mattress. So don't make this height too small!!

Finally, be carefull of weight. We started out aiming to build our own camper on a U1300l but one came up for sale at a price we couldn't ignore. Sometime later we discovered it was a bit less than 9 tons on the 7500kg chassis. Since we had wanted a Mog to take off the beaten path and be well within its design limits this was a bit deflating as well as "illegal". So we transferred the camper box onto a dimensionally similar U1700 and are now well within its limits rather than running at them all the time. A mistake which cost us a lot of cash, as well as travel time due to UK offialdom with change of use and my licence. There is no reason you can't stay under the 7500/8500kg whatever yours is, but you may well go over unless you keep an eye on things perhaps?

Good luck and happy travels in whatever you end up with