For a year now I have been using a 4-cycle Thule carrier mounted on the towball of my Scenic II.
My son is now looking for a new bike for Christmas and as we have been looking , I have been trying to find out the weights of any prospective bike (he wants all the suspension etc and I want him to get a light bike!)
Anyway this prompted me to do a check. My Scenic max towball weight is 75kg. The bike carrier itself weighs 19kg which leaves me 56kg for 4 bikes. The Thule website states that the carrier can take max 60kg.
I have weighed the 4 bikes we currently use (by standing on the scales with and without the bike - is this accurate?) and their combined total is 62kg!
So I have been driving about with too much weight on the towball, how critical will this extra 6kg be? And too much weight on the carrier as well!
Incidentally I have a relatively light bike at 14kg so the Thule is obviously built for only taking lightweight bikes and not mountain bikes with chunky tyres and suspension!
Beginning to think that one bike is going to need dismantled and put in the boot which kind of defeats the purpose?
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I think a Transit is more in your line.Why not get a roof carrier and put two up there.
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I'd have thought you were quite safe - it's not the 'static' weight that causes problems it's going over the bumps - shockload forces are much higher! As long as you avoid the big potholes, you'll be fine.
Perhaps it's worth inspecting the bikerack every so often, if there's any flexing or cracking of welds it'll show by making the paint flake off.
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Your overload would be important if you need to make a warranty claim, either for the car or the towbar. The warranty would be void if it relates to the towbar.
Theoretically you could be prosecuted for having an unsafe load but not likely in practice.
If you tow a caravan, trailer, etc while the carrier and/or bikes are attached then the trailer noseweight needs to be reduced to avoid the total towbar load exceeding the limit. With bikes on, this would need negative trailer noseweight which is unstable and very dangerous.
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I'm assuming you don't have a caravan on the towball at the same time as the bikes!
I'd have thought the transient load from a caravan would go well above the 75Kg, so your small additional static load is unlikely to do any damage.
Legally of course you have no choice - you must not load above 75Kg.
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Definitely no caravan, just the bike carrier!
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You would hope that any engineering calcs. used to define the max weight will have added in at least 30% fudge factor. 10% over is neither here nor there I reckon.
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i have just been to a site with the recommended weights for these things and i think you are pushing things too far ,12 pounds in old money is nearly a big bag of spuds so on its own its plenty ,times that by the fact its over the manufactured spec and you may well fracture a support or due to the way everything is bolted together it might rip out of the floor in your car.
The least you need to do is put the heaviest bike nearest to the car to cut down on the leverage effect.
I am now more aware than ever when i follow these things that they are not the ideal solution and that a friend has the right idea as he bought and modified a trailer.
no offence meant mind----
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It seems to me that you are comparing different specifications used in different circumstances. The maximum tow ball weight is to ensure that a trailer or caravan is loaded correctly. It should have a certain amount of loading at the tow ball, for stability, but no more than specified otherwise it puts too big a load on the car's suspension and causes instability. It's not the same thing as having a pernant additional weight in the back of the car. Having a sack of potatoes in the boot isn't going to make the car unstable, but having 50lb excess nose weight on a caravan might well make the combination unstable.
I should have thought the relevant figure to abide by was the maximum permitted car carrying capacity - or more specifically, what is the maximum weight you can carry in the boot?
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Oldman, I used to have a modified trailer which I used for carting the bikes about but the Thule seemed to be the dog's bits as far as cycle carriers were concerned and of course you didn't have the problems of where to put the trailer when parked up, not being able to use the outside lane etc.
However this weight thing is really making me think now. I appreciate the load figures may be different in comparing a cycle carrier to a caravan. However if the limit is 75kg, then if I have got more than that, which is all resting on the towball then it will also be subject to the same pressures when hitting potholes etc?
Incidentally, I do take the heaviest bike at the side nearest the car. That is my 12 year -old daughter's bike which weighs an incredible 18kg, for a front/rear suspension bike!
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I wouldn't worry-as has been said in a previous post, most of the 'nose weight' figure is down to the dynamics of having a trailer or caravan etc heave-hoing right at the back of the car-I don't believe having a cycle carrier on the tow bar is the same thing. Besides, a couple of extra KGs is nothing, these limits are specified with large safety margin built in.
Think about the case of a trailer or caravan on the tow bar-an extreme bump in the road etc even at or under the specified nose weight will cause a much larger shock loading through the tow bar than the cycle carrier, because the caravan or trailer is hinged at it's axle it gives it forms a lever between the fulcrum (axle of trailer) and the towbar connection...they don't tend to break free. A cycle carrier is effectively a static weight and certainly has very little leverage.
The way you are weighing the bikes will work, within the limits of accuracy of the scales-and don't kid yourself about how heavy you are, it will cause you to falsely read your results;-)
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I can't imagine a towball and towbar which is sized to pull a heavy caravan or trailer being over-stressed by 75kg of bicycles and bracketry.
I think that the main reason for setting this limit is to avoid the front axle becoming light, and the resulting loss of steering and degradation of handling. If your car handles well when loaded, I wouldn't go any further.
Number_Cruncher
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I can't imagine a towball and towbar which is sized to pull a heavy caravan or trailer being over-stressed by 75kg of bicycles and bracketry.
Exactly. You can lift my car by putting a jack under the tow bar, or use it as the attachment point for winching up onto a recovery vehicle. A few bikes aren't going to stress something designed to carry 2 tonnes.
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>>, I wouldn't go any further.
I've just realised how open to misinterpretation that sentence was.
What I meant to say was, if the car handles well when loaded with bicycles, I would continue to use the car in this way, and not investigate the issue of towbar loading any further.
Number_Cruncher
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I emailed the dealers who I bought it from and their answer is
"The 903 load capacity is 60kg, which equates to 3 x 20kg bikes or 4 x 15kg bikes using the 4th bike adapter.
2kg over this weight will not pose a problem for the rack and I suspect that 6kg over the recommended towbar load is unlikely to be an issue."
This seems to back up the majority of posts on this thread so I will relax a bit more now, though will still try and get my son the lightest possible bike at Xmas!
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Whoever wrote that at the dealer should be sacked. I doubt he has a corresponding email from the manufacturer.
As it is, I imagine that the margins of design will ensure he'll be right.
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