Fiamma Bike Rack Failure

Bridgetjones3 wrote:Our e-bikes are 42kg for both. We have and end bathroom. They stated it would be ok for up to 50kg.

If its a mechanical fixing it might only be for the top bar with on the Nuevo, one fixing through the shower wall like Cymro's and the other out of sight through the wall behind the cooker, so requiring the cooker to be removed.  

If the two e-bikes weigh 42 kg and the reinforced e-bike rack weighs 10 kg, that's more than 50 kg and that's before covers, bike locks, marker board and a lighting board have been added.

Just come across this thread from 2021.  I must have missed it.  The issue has been going on since at least then, I assume on 2019? models onwards with the re-designed rear wall.

https://www.autosleeper-ownersforum.com/t37054-bike-rack-fell-off

This afternoon I finally got through to the A-S Service Centre by phone.  Karen has left which explains why my e-mails to her went unanswered.  The lady I spoke to gave an A-S party line which is that the problem has been caused by people putting e-bikes on their rack.  It remains A-S policy that e-bikes should only be carried on a tow bar or chassis mounted rack.  She said the product enhancer (fitted cost about £126) does not return the rack's load capacity to Fiamma's figure of 60 kg or even 60 kg including the weight of the rack.  She said the maximum capacity remains at 50 kg including the rack.  She was non-technical so couldn't answer my subsequent questions so she transferred me to a technician in the workshop.

The technician explained that first of all they check the condition of the sealant on the upper mounting bar.  If it looks dubious they remove the upper bar, clean it and reseal.  They then drill holes through the fibreglass wall and wooden fillet and insert the sort of butterfly fixings that are used on internal plaster board cavity walls that mechanically secure the upper bar to the fibreglass wall. They only do this to the upper mounting bar as this is where the cantilever forces are.  They don't drill through the rear sandwich wall that is behind the fibreglass wall. He said this substantially strengthens the fixing and in his opinion allows the previous 60 kg including the weight of the rack to be restored.  I didn't discuss e-bikes with him.  He said the job takes about 1 hour.

I look forward to hearing from Bridgetjones3 when their's is done.

Presumably you mean “spring toggles”?

https://www.screwfix.com/p/easyfix-spring-toggles-5mm-x-50mm-20-pack/4257X?tc=VA6&gad_source=1&gclid=CjwKCAjwyo60BhBiEiwAHmVLJWJpeMCnw94fOCeSeT8Nnux2lgAu7Ujl59HdHtcxjBM-WlEBL75jKhoCl4AQAvD_BwE&gclsrc=aw.ds

I guess they are made to be at least as strong as plasterboard.

I think its going to be something like Paul's last FB photo but don't know how the two large metal collars fit in.  Obviously with a phone call you don't get a complete understanding.  It should be clearer at the end of the week after Bridgetjones3 has had the treatment. I almost certainly will have it done even though with just one pushbike I'm no where near the load limits.  I'll probably take it to Willersey.  It's a nice part of the world and I can combine it with a trip.

Presuming that the inner lining is the normal AS 12mm lightweight plywood, and seemingly only lightly supported, then I am not sure how much any bracing such as photographed will add, whether or not the bracing is strong or flimsy.

I can't make out the other kit. The bolts are not the right size for what appear to be tubular spacers, and what are the strap-like things?

How thick is the GRP back panel moulding? It looks as if the inner laminate is woven rovings, which suggests it might be a good laminate. How big is the gap. 60mm? 

I think I would want to see a good large 18mm plywood spreader pad glued to the outer laminate, which might in itself be enough, but would be tempted to slide in a further wide batten, or build up layers of plywood to bridge the remaining gap between the plywood pad and the lining, all through bolted.

It all seems rather a poorly engineered solution and I will continue to avoid tailgating motorhomes with bikes or boxes on the back!

I've just had another look under the van this time with the help of my mobile phone.  Things are not as bad as first thought.  Where the two Fiamma mounting bars are located there are substantial battens (two for the lower mounting bar and one for the upper bar) seemingly glued to the inside surface of the fibreglass outer wall.  It may well be that the Fiamma mounting bars are screwed into the battens as well as glued onto the fibreglass.  Attached to the battens are full length metal brackets which seem to be secured with screws and adhesive onto the outside surface of the inner wall.  I suspect this isn't just for the Fiamma mounting bars but also to help hold the rear fibreglass wall in place.  Above the mounting bars a further long batten can be seen between the the two rear walls which must also be to provide structural integrity.  The rear fibreglass wall certainly appears to be very secure.  Paul's FB photo below shows what the top bar looks like before modification:


Enlarge this imageClick to see fullsize



I suspect the modification is to drill holes from the outside through the batten that are wide enough to take a spring toggle / butterfly fixing that is then tightened from the outside so it pulls the mounting bar onto the batten.  In this way it isn't just relying on the adhesive or wood screws.  I suspect it's too difficult to do it any other way.  I have long relatively thin arms and could only just touch the bottom of the upper batten which is impossible to see with the naked eye.  Trying to get a nut and washer onto the end of a coachbolt poking through the batten would be difficult and even more difficult to hold it in place whilst its tightened.  That said, I'm not a mechanic and mechanics can do clever things.

When Bridgetjones3 gets their's done tomorrow a photo like the one above, taken with a mobile phone looking upwards into the void between the two rear walls, should reveal all.

This is the photo I took yesterday but have struggled to upload until now from my mobile phone due to poor internet.  I am assuming the adhesive used is Sikaflex or something similar and I have less between my batten and the inside of the fibreglass wall than Paul's FB photo.  However, my photo shows the metal bracket more clearly and the batten above that secures the fibreglass wall to the rest of the structure.  I have not attempted this before but I am wondering whether a nut and washer could be superglued to the end of a long handled spanner and then by feel located onto a through driven coach bolt being turned from the outside by a second person.  Once tight the superglue could be broken and the spanner removed.  This could be a stronger fixing than one being used by A-S and more like the through bolts used by Fiamma.

I don’t know the model at all but it seems that the upper bike carrier batten is just below the sloping part of the rear panel (that slopes up and inwards towards the window. That is good news in that the angle will stiffen the moulding quite well.

It would appear that forward of this area is the cooker and some drawers.

Can you not remove these and make access to that batten. I am thinking drill right through from the outside (through the bolt holes in the carrier bar) with an extra long twist drill to pinpoint the locations. Then use a hole saw from the inside to cut holes in the lining big enough for a socket on an extension bar, and/or big enough to get some good large plate washers through as well. Indeed if the area is hidden behind the cooker you could cut a much larger hole(s) to perhaps insert some additional stiffening. Any holes would be easy to cover afterwards, or first obtain some blanking caps and size the hole saw to suit. You would also get better access to insert some insulation!

The Bargee wrote:I don’t know the model at all but it seems that the upper bike carrier batten is just below the sloping part of the rear panel (that slopes up and inwards towards the window. That is good news in that the angle will stiffen the moulding quite well.

It would appear that forward of this area is the cooker and some drawers.

Can you not remove these and make access to that batten. I am thinking drill right through from the outside (through the bolt holes in the carrier bar) with an extra long twist drill to pinpoint the locations. Then use a hole saw from the inside to cut holes in the lining big enough for a socket on an extension bar, and/or big enough to get some good large plate washers through as well. Indeed if the area is hidden behind the cooker you could cut a much larger hole(s) to perhaps insert some additional stiffening. Any holes would be easy to cover afterwards, or first obtain some blanking caps and size the hole saw to suit. You would also get better access to insert some insulation!

Thanks Bargee.  I am sure the upwards slope of the fibreglass wall to the securing batten just below the kitchen window must help.  If my schoolboy mechanics serves me right, a moment of tensile force will be taken through the fibreglass from the Fiamma upper fixing bar to the securing batten below the window and fibreglass is strong in tension.  As you say the general form of the fibreglass back wall will also give it rigidity.  As I have said before, it all feels pretty strong.  There is a bit of flexing but not as much as I have encountered on some composite bumpers.  

The whole rear wall is a bumper.  Filling the void between it and the insulated rear sandwich wall with glass fibre wadding sounds appealing but I'm not sure how much difference it will actually make.  The main heat loss is at the front where the cab is.

Unfortunately the off side fixing bolt for the Fiamma top bar would be in line with the shower wall so drilling a big hole there to take a socket would be invasive and require some cosmetic work to cap it.  I don't think I would get domestic approval for it especially as my wife understands all too well the limit of my DiY skills!  A hole for the near side bolt should as you say be out of sight behind the cooker/kitchen unit so less of a problem.  I still like the idea of a Nyloc nut, with the largest washer possible superglued to it, being manoeuvred into place on the end of a suitably slim long arm ring spanner.  It would be fiddly and patience testing but I think it could just be done with a supportive assistant.  First though I would like to see what the A-S solution is in more detail.  All eyes on Bridgetjones 3!

Thanks Paul for all that info and thanks John McHale.  Somehow I got it in my head that Bridgetjones3 was having the mod done today so apologies all round. The end result is two steel bolts through the Fiamma top mount, wood batten and metal bracket that is threaded onto a short bar that when tightened holds the Fiamma mount onto the fibre glass wall.  The 13mm oversize holes seem a little clumsy but presumably they know that drilling a smaller  hole perhaps with a fatter bolt where the wood screws are and then trying to thread a nut and washer onto the end of the bolts is too difficult.  

It is disappointing that even with the modification, A-S feel they cannot return the weight limit to its original 60 kg including the rack, let alone 60 kg excluding the rack which is the Fiamma specification.  This suggests to me that without the mod the rack limit should be less than 50 kg including the rack, perhaps only 40 kg which should be just enough to allow a couple of alloy pushbikes to be carried plus a cover, bike lock, marker board and lighting board.

John McHale wrote:Having had the modification, sorry "product enhancement" , I have not been advised of any reduction in the weight limit from the 60kg of my rack, Pro C with ebike rail upgrade. Looking at new vans the rear bar is different, much smaller/thinner hence, I assume, 50kg inc. rack, with relevant sticker to that effect on the bar with no rack.

Thanks John.  So if the rack weighs say 7.5 kg, is it your understanding the maximum load on your modified fixings is 60 kg as per the Fiamma manual or 60 kg minus 7.5 kg = 52.5 kg as per the A-S 2019 handbook?