hi all.how do manufacteres come up with a nose weight figure? looking to fit a bike carrier to my tow bar which has a limit of 100 kgs.witter bar. witter web site has tow bar mounted carriers to carry up to 65kgs. my caravan weighes 1800kgs so in theory needs a nose weight of120 kgs, i keep it about 95kgs. so the question is is this safe to use 65 + 95 =160 kgs. also if i accelerate hard while towing 1800 kgs van surely the forces on tow bar is far greater than 100 kgs nose weight. hope some one can under stand what i am asking
Do you mean a bike carrier on your boot and towing on the towball or a bike carrier on the towbar with an additional towball with your van on it?
My understanding is the max nose weight is what the steelwork under your car can take. After all cars are made of tin plate and there's only so much stress the plate can take. A tow bar is mounted (in my outlanders case) on 10 off M10 screws screwed into thread inserts. The screws and plate can take more load in shear than in tension.
When you pull away the screws are in shear. The nose weight imposes bending moments and tensile stresses on the screws.
If your bikes are strapped on the boot it's like having more weight in the car which is not a bad thing.
I will be carrying my bikes on a tailgate rack this season.
The witter ones have a mounting bracket that bolts to the tow ball frame itself so I get what he is saying, you could always load the caravan so the nose weight is slightly less?
Using a bike carrier on a bolt-on tow ball type towbar, I suspect no one actually knows the answer to this question.
Clearly under heavy braking the forces on the towbar are far in excess of the car manufacturers nose limit or even the towball structural limit so a static load limit is not represntsrive of the total dynamic forces the fitting can resist.
As pointed out the towbar download is arrived at due to mounting point strength. but not a exact science so getting exact weight is not as critical as some think, but obviously should not be exceeded by a large margin as you will end up with overloaded rear axle. If you get stopped it will be axle weights that will be checked, not towbar download.
If you have both caravan & bikes on towbar or bikes on tailgate carrier it would be worth checking real axle weight on car to check you are legal.
If the op has a total of 160kg download on towbar when limit is 100kg then clearly that is too much. Whatever forces imposed onto towbar when vehicle is in motion will have been calculated within the limit of the specified 100kg download limit. Obviously there will be a margin but a 60% overload seems excessive.
How far would the towbar rack with cycles stick out from the back of the car? Average adult bike is almost width of a car, so mounted on a towbar rack it basically extends the the length of the rear, obviously depends on how many bikes are on the rack.
Just thinking about reversing into a tight spot with possibly two or three bikes on the back which will shorten the distance between car and van..which in turn reduces the available angle to turn?
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Quote: Originally posted by VangoMan02 on 20/4/2015
How far would the towbar rack with cycles stick out from the back of the car? Average adult bike is almost width of a car, so mounted on a towbar rack it basically extends the the length of the rear, obviously depends on how many bikes are on the rack.
Just thinking about reversing into a tight spot with possibly two or three bikes on the back which will shorten the distance between car and van..which in turn reduces the available angle to turn?
OP has an Adria which generally have a longer A frame, so should be OK for a couple of bikes from that point of view but as others have said its the weight that is more the issue
I've gone with bikes on the roof in the end after looking at all these options previously, takes away worries over rear axle and noseweights
Quote: Originally posted by sunshinetours on 20/4/2015
Quote: Originally posted by VangoMan02 on 20/4/2015How far would the towbar rack with cycles stick out from the back of the car? Average adult bike is almost width of a car, so mounted on a towbar rack it basically extends the the length of the rear, obviously depends on how many bikes are on the rack.
Just thinking about reversing into a tight spot with possibly two or three bikes on the back which will shorten the distance between car and van..which in turn reduces the available angle to turn?
OP has an Adria which generally have a longer A frame, so should be OK for a couple of bikes from that point of view but as others have said its the weight that is more the issue
I've gone with bikes on the roof in the end after looking at all these options previously, takes away worries over rear axle and noseweights
I do realise that the Op was enquiring about weight but my post was to highlight another possible issue which is surely relevant.
As you say yourself, you put the bikes on the roof to take away any worries.
------------- It is a wise man who has something to say.
It is a fool who has to say something.
bikes on roof of a hyundai i800 is a no no. roof height 1m90, i am not carrying ladders around. as said extended A frame on the adria,so plenty room. have looked at an a frame mounting bike rack. ok to get to site but also need a rack on i800 if we go away from site on a day trip. i have a thule tow ball mounted carrier so was going to manufacture a bracket with a ball on it to mount on tow bar about 30 inch above excisting towball and mount my thule carrier on that above and clear of caravan a frame. all tow bar bolts were changed from 8.8 to 10.9 strength when i fitted the bar. as for axle weights.i have been over a axle weigher and still got a huge margin to spare. PS spoke to tow sure today and they don't sell any bike carriers that you can tow with.can only be fitted if not towing.????????????????? PPS 65 kgs is 2 adult bikes and a thule carrier, been on the bathroom scales !!!!
Quote: Originally posted by diesel steve on 20/4/2015
bikes on roof of a hyundai i800 is a no no. roof height 1m90, i am not carrying ladders around. as said extended A frame on the adria,so plenty room. have looked at an a frame mounting bike rack. ok to get to site but also need a rack on i800 if we go away from site on a day trip. i have a thule tow ball mounted carrier so was going to manufacture a bracket with a ball on it to mount on tow bar about 30 inch above excisting towball and mount my thule carrier on that above and clear of caravan a frame. all tow bar bolts were changed from 8.8 to 10.9 strength when i fitted the bar. as for axle weights.i have been over a axle weigher and still got a huge margin to spare. PS spoke to tow sure today and they don't sell any bike carriers that you can tow with.can only be fitted if not towing.????????????????? PPS 65 kgs is 2 adult bikes and a thule carrier, been on the bathroom scales !!!!
I was looking at a witter bike carrier for the kids bikes, I think that plus a caravan would be fine on our i800's. Like you said, bikes on the roof when the roof is a fag paper under 2m isn't going to happen!