Roof Rack mounting

[JonathanM]

OK, those who've seen my T2 will know that sometimes I'll use a Thule roof rack, currently mounted using the typical Thule clamp on roof bars- you can just see it in my avatar picture.

Now becuase the T2 is no longer going to be our primary towcar for holidays then I can start to make it less holiday friendly, but more suitable for laning.

I've considered trying to to obtain some roofbars as per the factory fit, but then a thought entered my head. The Thule roofrack basket uses 4 adjustable points to clamp to whatever roof bars are used. The thought that has entered my mind is whether to drill & fit the threaded captive nuts to the roof as a roofbar would require, but then because of the adjustability of the mounting points actually mount the roofrack basket directly to the roof, using some short spacers to ensure that the basket & items carried are not contacting the roof i.e. the base of the rack would be about 1 inch or so above the roof.

Allowing for the fact that this would mount the rack directly to the points that would be used on standard fit roofbars, then I'm assuming that the standard 50/75kg weight limit would remain in place, however the rack would then be mounted lower than either clamp on or standard fit roof bars would allow - meaning a neater fitment, and the ability to enter the multistorey car park at work which is something that I can't do now.

Any thoughts on this idea?

 

[Deleted Member S]

Hi Jonathan I priced up a set of secondhand factory roof bars fo my SWB & they wanted £80 for them 8O 8O 8O so I got the Thule bars :smile: I would think mounting the rack onto the roof skin may be a bad idea as I think the roof will crease or flex to much as there is'nt much strengh in it.

 

[JonathanM]

Hi Jonathan I priced up a set of secondhand factory roof bars fo my SWB & they wanted £80 for them 8O 8O 8O so I got the Thule bars :smile: I would think mounting the rack onto the roof skin may be a bad idea as I think the roof will crease or flex to much as there is'nt much strengh in it.

I was thinking this, but my idea would be to use a minimum of 8 bolts with some spacers to secure the rack to the roof, leaving a gap of 1-2 inches between rack & roof, so the actual weight of rack & load would be mounted in a similar way to how it would be if I used the factory fitment roof bars, ie 4 points of contact.

 

[Deleted Member S]

I see what you mean :smile: your roof may be stiffer than mine as mines fitted with an optional nissan tilt & slide sunroof :roll:

 

[theduck]

It's just a thought :| but it sounds like jonathan is an engineer of some degree could you not modify the thule roof bar so that you can lower it with out having to drill into your baby's roof ( I shudder to think orrible thoughts ) whats she done to you :?: you big bully :smile: surely there must be some way round yet acheive your goal :?: :?:

 

[JonathanM]

It's just a thought :| but it sounds like jonathan is an engineer of some degree could you not modify the thule roof bar so that you can lower it with out having to drill into your baby's roof ( I shudder to think orrible thoughts ) whats she done to you :?: you big bully :smile: surely there must be some way round yet acheive your goal :?: :?:

Unfortunately I'm no engineer, my thinking is that to get a neater mounting its either to drill the roof and fit roofbars, but even then I don't get the lower height that I'm after, or drill the roof and fit the rack direct to the mounitng. I'm not too concerned about the drilling of the roof, as one way or another its going to happen.

I'm after mounitng the rack further back & lower to the roof than the clamp on bars can achieve, and to fit roofbars would still mean the rack being too high, meaning i can't leave it fitted (for practical purposes this wpould be easier) becuase i couln't access the carpark at work with it fitted.

 

[Terranosaurus]

I think your main issue would be sealing the bolts to prevent corrosion. The standard roof bars (if they fit like most do) use a fitting that is bolted to the roofwith 2 bolts in to threaded inserts, the fitting has a hole in it laterally and the roof bar has a hole for a grub screw, This grub screw when tightened pulls the bars down on to the fitting. The fitting has a rubber gasket and the foot of the roof bar has a rubber gasket too, water could get in down the grub srew hole but this has a bung in it too.

I fitted skoda felicia estate bars to mine, these are longer and lower, but take all the same thule fittings and mount in 3 places each, I'm picking up a rack/basket a bit like yours at the weekend.

|Pic of roof bars HERE

I think if you use decent sized rubber spacers with as you say 8 of em you shouldn't have too much problem. The spacers may need to be different heights as the roof isn't flat of course.

 

[CHASTER]

Being a bit of a thicko on this subject I wonder about the loading on T2 roofs.
First off; I assume that the factory fitted roof bars are those which are mounted to the roof longitudinaly and any other roof bars are those which clamp to these and are positioned across the roof.
If all that is correct, my factory fitted bars are EACH marked with a max load of 55KG. Because there are two bars, one on each side of course, can I add the two and load the roof up to 110KG ?. Not really a vast weight, just a bigish person or perhaps four well filled suit cases.
I have had 70kg of timber on my T2 roof and it didn't SEEM at all stressed and the waggon didn't roll or lean much more than normal. Was I pushing my luck?

 

[theduck]

:| don't know about adding two together but I carry 3 adult bikes up on the roof easily :smile: and then a further 2 on a pendle bike carrier on the tow bar or on the caravan A frame :smile: being thay I have a large german caravan 8) :smile:

 

[Terranosaurus]

Have just checked my manual and its 55Kg max total weight on the longitudinal factory fit roof rails.

Interestingly its 75kg for the clamp on style according to the manual.

3 adult bikes will be under 55kg including the supports so you should be ok, depends on the individual bikes weight. My bike weighs 26lb or about 12kg, its getting on now but was considered pretty lightweight when new, more modern bikes are lighter but suspension etc puts the weight back on.

 

[theduck]

:idea: stick the mother in law up there :lol: :lol:

 

[JonathanM]

I think your main issue would be sealing the bolts to prevent corrosion. The standard roof bars (if they fit like most do) use a fitting that is bolted to the roofwith 2 bolts in to threaded inserts, the fitting has a hole in it laterally and the roof bar has a hole for a grub screw, This grub screw when tightened pulls the bars down on to the fitting. The fitting has a rubber gasket and the foot of the roof bar has a rubber gasket too, water could get in down the grub srew hole but this has a bung in it too.

I fitted skoda felicia estate bars to mine, these are longer and lower, but take all the same thule fittings and mount in 3 places each, I'm picking up a rack/basket a bit like yours at the weekend.

|Pic of roof bars HERE

I think if you use decent sized rubber spacers with as you say 8 of em you shouldn't have too much problem. The spacers may need to be different heights as the roof isn't flat of course.

Yep, was thinking of using rubber for the spacers, should be easy to get hold of & to trim to the right depth, sealing, I was wondering about using some mastic type sealer (as used on some body kits etc) but also use it on the bolt itself to try & prevent water ingress downwards.

Re weight limit,yep,clamp on bars seem to have a 75kg limt, I'd probably err on the side of caution and assume that anything using a roof bar type mounting needs the lower limit, for laning I usually chuck the big & bulky (not to mention muddy) stuff on the rack, so don't really challenge the weight limit too much, besides I wouldn't want too great a mass uptop to try & not upset the CoG too much.

OK, watch this space then,I'll post more as this plan develops.

 

[Deleted Member S]

Hi Jonathan :smile: I don't know if you can still get it but I used to use 3M Drip Check Sealer to seal bad welds etc on on cars & disco's we used to get in with water leaks. I've used it on my own cars over the years & it did stop leaks 100% & you can paint over it in about 5-10 mins :smile:

 

[JonathanM]

Thanks Sweety, i might keep an eye out for this stuff.

 

[Deleted Member S]

I would think a good motor factors should stock it or be able to get you some. I know it's very much like the stuff they use on the production lines when they seal the welds or as a lot of use find TRY & seal them :lol: :lol: :lol:

 

[Terranosaurus]

:idea: stick the mother in law up there :lol: :lol:

nah would be over weight - think Reggie Perrin.

 

[JonathanM]

Well,just to update, I looked into the practicalities of fitting the rack direclty, and I'e decided not to, reasons being just practicalities, that seeing as the rack dents fuel consumption I don't want to leave it on with fuel at 1.06 per litre!!!

I've purchased some cheap (£21) roof bars from a Citroen (!) Berlingo van, length matches those fitted as standard to a SWB, so they are quite short, 3 1/2 foot or so, but I've measured the space between mountings on the clamp on rails I use, and they are about the same. These should let me fit the rails and mount the rack further back than the clamp on one allows. I just need to sort out some cross rails and take it from there.

 

[Deleted Member S]

Hi JonathanM would changing the fittings on the Thule cross bars work ? it was just an idea :roll: