Any questions about the structural integrity of high tops?

[AltTransBikes]

Ever think there would be any strength issues with a high top when the integral roof section of the original factory vehicle has been cut away? Take a look at this typical high top with the headliner out. (thanks MrNoodly for the pic)<br><br>

 

[Les H]

In an actual roll-over-land -on-the -roof accident, they are not as strong, but they have to meet yhe NTSB specs, same as any other vehicle part ( 5mph bumpers , for instance)
edited to add- the bus has a steel roof with 1x1 1/2 steel tube framing. Bus's are some of the safest, sturdiest vehicles made.

 

[MrNoodly]

This is one reason Sprinters and Nissan NVs are appealing — all steel high roofs and rib structures.<br><br>It's tempting to have a roll cage built with fiberglass roofs.<br><br>With the particular van in the photo, it would have been better if they'd left a few more inches of original roof at the front — enough to connect to the vertical structure around the door openings. And with the way we tend to put beds across the back, they could have left a foot or more of roof at the back to help keep that end tied together better. In fact, with the way we lay out these vans, it would probably work to remove just a 3 foot wide section of roof down the middle with a bit more cut out by the side door.<br><br>I don't know how common van rollovers are, so I don't know how concerned to be.<br><br>Oh, and I would guess that particular high top is about as thick as a fiberglass boat, for what that's worth.

 

[highdesertranger]

i really don't know about today but back in the day when i did van conversions, ntsb had nothing to do with aftermarket parts except for brakes.&nbsp; come to think about it that was dot that regulated brakes.&nbsp; anyway those tops could run from great quality to junk just came down to how much you wanted to pay.&nbsp; highdesertranger

 

[idn88]

I would have to imagine there is zero lateral integrity to the walls left - meaning even laying it over in a ditch, or getting hit broadside would collapse the walls. &nbsp;The roof adds a huge amount of structural rigidity and integrity to the whole vehicle. &nbsp;Think of cutting the top off a tin can - becomes really easy to squish.<br><br>In the picture above, you can see right behind the seats where one of the main supports was cut out - essentially rendering it useless since there is no support at the top.<br><br><br><br>

 

[MrNoodly]

Besides structural integrity in a crash (which is way down on the list of things likely to happen), there's the matter of the body flexing and distorting, making it so the doors go out of alignment and don't close properly anymore.To get an idea of what's going on, take a cardboard box that's all sealed up and try to push opposite corners toward each other. Then cut off the top and try it again.<br><br>And because of the different rigidity properties of steel and fiberglass, I can imagine the attachment points and the seal between the two suffering a lot of flex.<br><br>I think I'm talking myself out of a high top conversion and into a Sprinter or Nissan NV.

 

[bpeck]

Pretty sure I can feel my van flexing as I go over uneven/rolly sections of pavement. &nbsp;When the road is nice and true (like a freshly paved highway) it tracks really straight, but on sections of road that are banked I can feel it pull to different sides. &nbsp;It was really weird at first but like anything, the more you do it the more you get used to it.

 

[gman97005]

because of it's concave shape it is almost as strong as the steel roof.. &nbsp;

 

[MrNoodly]

The shape is strong against some types of loads (like from above) but weak against other types (like from the side). On a 2-foot high top, the sides are essentially flat.

 

[Ballenxj]

WOW, after reading some of these replies I think I may just stick to a conventional roof van. <img src="/images/boards/smilies/eek.gif" class="emoticon bbc_img"> <br>-Bruce

 

[drivebyandy]

<p>Seems like a lot of unreasonable fear disguised as an excuse to not live your live the way you want. If you roll anything you're having a bad day. <br><br>Be aware, drive a reasonable speed, and have new&nbsp;experiences.</p>

 

[Seraphim]

Wouldnt have traded our 95 high top Class B for any of the Sprinter style versions. Never had an issue with doors or anything else, never a concern about rolling it over...<br><br>...and it was 17 years old when we sold it. Any issues would have shown up then, I would think.

 

[wagoneer]

fear not, the odds of you rolling over are slim being hit in the back with loose cargo being rear ended would be a much greater fear for me. Driving skills are paramount defensive defensive defensive leave space before you and behind you travel at hours fewer are on the road keep it under 60 mph F#%$ the guy honking at you a lot of people are super stressed these days and take it out on the road it's called road rage beware this phenomonem??? I can't spell worth a darn

 

[AltTransBikes]

<span id="post_message_1277102940">"Seems like a lot of unreasonable fear disguised as an excuse to not live your live the way you want."<br><br>No, not necessarily. No more than the comment above is projecting feelings onto others that aren't necessarily there. <br><br>I asked the question because I value the opinions from folks here, many who have more experience<br>with this configuration or possibly even have industry experience building them. <br></span>

 

[Van Tripper]

Steel vs Fiberglass, this discussion has been raging in big trucks for years. &nbsp;Steel expensive, fiber less, nothing is cheap.<br>Steel is harder to crush but will stay that way and you can be trapped, fire or under water would be a problem and difficult to be rescued.<br>Fiberglass splinters and would allow escape or easier rescue. &nbsp;Rollcage would need to be properly done or becomes a danger itself. &nbsp;<br><br>If bought commercially they all are supposed to meet national spec, as mentioned by another poster, but if built by a DIYer, like me, pay attention to roof and side, bows/ribs, reinforcement.<br><br>Be safe, better to over build. Does not mean heavy, just more ribs and bows.

 

[SoulRaven]

Greetings!

Well, my 1982 Dodge High Top 15 passenger window van, has over 500k miles now, and still drives like brand new. So I don't think it has ever had any flexing issues, and it has never felt top heavy either.

It's getting kind of old and tired like me, has a few dings, and some rust issues, but hey, it's still presentable, and she'll cruise at 90+ all day long if I ask her to, and I won't feel worn out after a full day or more of driving, and all of the amenities of home are within easy reach... What more can a guy ask for?!?!?!?

Viva la HighTops!

The CamperVan_Man

 

[Optimistic Paranoid]

Considering all of the ambulances that are high top vans, I wonder if the government had them subjected to a full round of crash testing before they were approved?

Regards
John

 

[owl]

Bikes is right here, there is a difference in commercialy produced HTs and something turned out in a buddys garage. The problem is acertaining if the roof was done properly or not. Roofs are the biggest problem, bar none, in RVs of every kind.

 

[Blue]

I got an old high top, I don't notice flexing, but I do have some cracks, insulation problems, and one leaky area

 

[flying kurbmaster]

If you were take the lid off a can and squeeze it as someone mentioned it would certainly be a lot weaker however if you simply took a hole saw and drilled it out and left a few millimetres of lid around the edges I doubt the integrity would be compromised to same extent. The extra height far outweighs any dangers in my mind.