Bike carrier rack

[rileys]

Hi is the motorcycle carrier rack for a Bultaco Sherpa t any good. It would be on back of a new navara any recommendations. Or leave alone ?

Greg r

[suzuki250]

I've used a DC rack on various cars and vans in the past without any problems

I use a trailer now, because I now have a small car. The rack was a lot more convenient to use

Edited July 18, 2020 by suzuki250

[timdog]

I assume you mean the likes of a Dave Cooper rack, If I only need to transport 1 bike I use a bike rack on back of freelander. Fantic is perfectly safe/secure and well under the nose weight.

You can check the speck for Navarro but pretty much guarantee to be fine.  

[cleanorbust]

My pal uses a Navarro to carry his Beta on a rack. As far as I know it has zero effect on driving.

Edited July 18, 2020 by cleanorbust

[rileys]

Thanks guys it’s sounding positive Greg 

[chappo]

I’ve had a DC bike rack for five years now on a Renault 4x4, it’s taken modern bikes and a variety of twinshocks, never had an issue. No speed restrictions, or reversing issues. Lot more stable than you’ll probably think. DO check the nose weight of the tow bar you’ll be using. 
 

[rcgods]

Like @chappo says the nose weight is an issue.  Even modern trials bikes are too heavy for a lot of cars

Edited July 25, 2020 by rcgods

[al_orange]

I've used a rack on big estate cars for 9 years. Technically, it's easy to exceed the nose weight but I contacted my insurance (once) and they sent me a letter saying that I am still insured if I carry an enduro bike on the rack - which exceeds the 85kg nose weight by about 30-40kg.

I'm not sure what the actual legal situation is with nose weight but for various reasons, I'm buying a Freelander which has a nose weight of 150kg so that there's no quibble. However, reading the manual, it states that the nose weight is generally 150kg but can go up to 250kg as long as the rear axle isn't overloaded. Which makes me question just what the nose weight limit really means. Nose weight is relevant for towing due to the dynamic forces and weight ratios between car and trailer and therefore, I'm not sure that carrying a load on the tow bar is the same thing... 

 

Does anyone have a definitive and reliable source for information on this issue?

[trapezeartist]

21 hours ago, al_orange said:

Which makes me question just what the nose weight limit really means. Nose weight is relevant for towing due to the dynamic forces and weight ratios between car and trailer and therefore, I'm not sure that carrying a load on the tow bar is the same thing... 

My thoughts too. "Nose weight" or "Nose load" is a parameter of a trailer. A bike rack doesn't have a nose so I don't see how the law or an insurance company could claim you were exceeding a specified nose load.

Just going at it from first principles, the issues are the strength of the tow bar mountings and the effect of the weight on the vehicle dynamics. The latter is likely to be the point of most concern. Having the bike overhung well behind the rear axle means that it adds more than its own weight to the rear axle and takes some weight off the front. I just ran through some typical figures and a car that start unladen with 45% of its weight on the rear axle would have 55% when fully laden and 61% with the bike rack and not much else apart from the driver. With a vehicle engineering hat on, I would say that takes the loading outside of design limits. With a pragmatic hat on, I would say the drive needs to be a bit extra careful when using the bike rack.

[al_orange]

My experience, using large estate cars, is that in a wet field or incline, there is definitely less weight on the front but it doesn't impact road driving, assuming you are just driving normally. This is with an enduro bike. With the trials bike (that comes in under the nose weight limit) I can't even tell it's on there. 

[ChrisCH]

On 7/26/2020 at 5:30 PM, trapezeartist said:

My thoughts too. "Nose weight" or "Nose load" is a parameter of a trailer. A bike rack doesn't have a nose so I don't see how the law or an insurance company could claim you were exceeding a specified nose load.

Just going at it from first principles, the issues are the strength of the tow bar mountings and the effect of the weight on the vehicle dynamics.

Yes, you have understood it correctly.  Tow bars have a weight limit that they are designed to "carry" which is the equivalent of the nose weight imposed by the trailer.  As well as the recommended capacity of the vehicle you must ensure the weight capacity of the tow bar is adequate.  The tow bar manufacturer will supply this weight capacity on request.

The insurance company could propose that the capacity of the tow bar is exceeded.  In practice I am sure they don't bother unless somehow the claim revolves around the bike rack (ie it fell off with the bike on it)

Years ago people used to fit coil spring assisters for towing to beef up the rear springs.  These are still available from most trailer/caravan outlets.

I am sure Dave Cooper would weld up aluminium bike racks if we were all willing to pay for them.  That would save a few kilos and probably bring the bike/rack into line.

[dpyam]

Surely the nose weight rating of the car is the downward force the car's towing 'setup' is designed to cope with. The car's metal won't care if the force is a trailer, a bike rack or a large person standing on it.   I'm sure the car manufacturer allows a safety margin, but if this limit is exceeded, while the tow ball/arm will be fine,  there is a risk of the relevant parts of the car it's attached to failing/snapping, leading to your bike bouncing down the road.

Note also that with a bike rack, the force is not always vertically down.  The combination of tow bar and bike rack act as a lever on the towing mount, increasing the forces involved when you go over a pot hole.

Please note I'm all for a bike rack setup.  I once had a DC bike rack (an excellent piece of kit) bolted to the back of an old Land Rover (directly to the ladder chassis via a genuine Land Rover mounting plate) and it felt like you could have had 1/2 ton hanging off it.  But modern cars are designed with every component being as light weight (read 'thin') as possible, so I'd not want to exceed what weight the car's manual says it's designed for.  It just gives anyone else's insurance company an excuse not to pay out.

Edited August 1, 2020 by dpyam

[al_orange]

1 hour ago, dpyam said:

Surely the nose weight rating of the car is the downward force the car's towing 'setup' is designed to cope with. The car's metal won't care if the force is a trailer, a bike rack or a large person standing on it.   I'm sure the car manufacturer allows a safety margin, but if this limit is exceeded, while the tow ball/arm will be fine,  there is a risk of the relevant parts of the car it's attached to failing/snapping, leading to your bike bouncing down the road.

Note also that with a bike rack, the force is not always vertically down.  The combination of tow bar and bike rack act as a lever on the towing mount, increasing the forces involved when you go over a pot hole.

Please note I'm all for a bike rack setup.  I once had a DC bike rack (an excellent piece of kit) bolted to the back of an old Land Rover (directly to the ladder chassis via a genuine Land Rover mounting plate) and it felt like you could have had 1/2 ton hanging off it.  But modern cars are designed with every component being as light weight (read 'thin') as possible, so I'd not want to exceed what weight the car's manual says it's designed for.  It just gives anyone else's insurance company an excuse not to pay out.

I generally agree with what you've said but I think the nose weight is much more about safe handling and relative weights when towing a trailer. The forces acting on the car when towing are far greater and far more dynamic than when carrying a bike on a rack.  I'm not an experienced tower but reading the owners manual, it says that it's actually preferable to try to meet the nose weight rather than have a much lighter load on the tow bar. I'd say that as long as the tow bar is rated to take the weight, and you don't overload the rear axle weight then the car would not be at all damaged. Whether it's legal/insured or not is another (and more ambiguous) question.

[ChrisCH]

On 8/1/2020 at 7:54 PM, al_orange said:

I generally agree with what you've said but I think the nose weight is much more about safe handling and relative weights when towing a trailer. The forces acting on the car when towing are far greater and far more dynamic than when carrying a bike on a rack.  I'm not an experienced tower but reading the owners manual, it says that it's actually preferable to try to meet the nose weight rather than have a much lighter load on the tow bar. I'd say that as long as the tow bar is rated to take the weight, and you don't overload the rear axle weight then the car would not be at all damaged. Whether it's legal/insured or not is another (and more ambiguous) question.

You are both pretty much correct.  The nose weight keeps the centre of gravity correct so that the towed equipment runs correctly behind the vehicle.  If the nose weight is too little the centre of gravity is too far back and the towed equipment will "snake" (or weave about on the road).  Typically you see this with caravans where the ##@# has put all the trinkets and beer supplies in the back of the caravan without thinking.  Car transporters are another one as the load is "parked" too far back.  You can buy anti-snake couplings (standard on most caravans to allow for the idiots that tow them).  These grip the tow ball slightly to reduce the articulation.

Modern vehicles attach the tow bar to the chassis in the same place as the rear collision absorber.  They are immensely strong and almost certainly capable of handling far more than the design weight of the bar and the car's approved towing spec.  Overloading the rack will be very detrimental to the car handling and I guess this is the area where the insurance company and police are going to concentrate if you have a problem.  Like most things, you get away with it until there is a problem, then make a fool of yourself telling the copper "I've been doing this for years mate".

Trials bikes are a relatively light item and so can just about be carried on a bar mounted rack like a push bike.  Adding much other weight might be a problem with a light passenger car but most cars designed for a load will be just fine.  A trailer lets you two two bikes and let's be honest who doesn't need at least two? ?

[Mcasp]

What about a rack with a trials bike on and a trailer with another ? Using an insignia estate 2ltr diesel????