Tow bars and roof boxes - advice on expanding storage space for travelling

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jonathan18

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#181401 14-Oct-2015 12:39

Hey,

I'm interested in trying to increase our luggage space for when going on holiday with all the kids' stuff in our main car (a '13 Mazda 6 wagon), so I am looking at either purchasing roof bars and a roof box and/or sticking a tow bar on the car, which could be used for a trailer or a bike rack.

Tow bar-wise, I know the official dealer-installed tow bar is stupidly expensive ($1500sh I think I was quoted); the guy I spoke to at the local dealership tried to scare me off going for anything less, claiming it was risky (he claimed due to the 'sophisticated electronics' in modern cars) and would void the warranty. Can someone please confirm whether this advice is correct, or whether I can essentially have any tow bar installed without problems? Will I need a model-specific harness, or is it as easy as the guy I spoke to at Repco, who said I could just purchase one of their standard harnesses and piggy-back the wiring off the rear light cabling?

Roof box-wise, are there any particular brands to look for or avoid? Does a particular brand of box require the same brand of roof bars to be fitted? I've looked at the Prorack brand initially, and while expensive when full-price, I recall seeing Repco and Supercheap often do significant discounts on these. There are also lots on new ones on TM, the brands of which I've never heard of.

Also, are the more expensive/more streamlined bars significantly quieter and/or more aerodynamic compared to their cheaper cousins?

Thanks in advance for any advice.

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#1405643 14-Oct-2015 12:53

I can't speak for roof boxes but I reservations about them. As for tow bars I do not use OEM bars as they are too expensive, I have always used Eastcoast Bars in Wellington as their prices are very good (average $350 installed with electrics). However before installing I get assurance from our car dealer that the install won't impact the new car warranty.

graemeh

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#1405657 14-Oct-2015 13:24

I have used two brands of roof boxes, Hapro and Thule. I would have just bought the Hapro (I rented one for a trip) but it wouldn't fit under our house for storage so I bought the Thule instead.

If you go with a roof box make sure that it does not interfere with the back door of your wagon.

The Hapro and Thule both seem to be top quality boxes. Phil from "The Roofbox Company" sells on Trade Me as "dudes1" and is great to deal with. They ship the box to you or if you're in Wellington he will fit it to your vehicle. I see they also have an Auckland showroom now so I expect they can provide the same service in Auckland too.

I don't know if the "aerodynamic" roof bars are better than the square ones. I do know if you leave the rubber strip out of the aerodynamic bars you get a nice whistle around 100 km/h. I believe this is a safety feature created by the manufacturer so you don't need to look at your speedo.

When I'm not using the rack I remove it.

Most boxes come with "U" bolts that go around the bar so it doesn't matter too much what bar you have. Some of the brand name bar and box combos use hidden bolts that fit into a slot on the top of the bar.

Renting the box is also an option, you'd probably have to buy the rack though.

Also make sure that you don't get a box that is too wide, you need to be able to reach the back of it while standing in the car door.

Driving with the box on seems to add about 10% to my fuel consumption.

jonathan18

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#1405663 14-Oct-2015 13:36

MikeB4: I can't speak for roof boxes but I reservations about them. As for tow bars I do not use OEM bars as they are too expensive, I have always used Eastcoast Bars in Wellington as their prices are very good (average $350 installed with electrics). However before installing I get assurance from our car dealer that the install won't impact the new car warranty.

East Coast Towbars does seem to get recommended by lots of people. I've confirmed with them it would cost $450 for a standard towbar on the car, and $480 for one with a removable tongue. They said two bolts would need to be undone to remove the tongue - has anyone had such a towbar fitted by East Coast Towbars, and is that how the removable ones normally work? I'd prefer one that left as little visible on the outside, for both aesthetic and practical (shin-protection) purposes, but also don't want the removal/insertion process to be too big a hassle...

BTW, what are your reservations about roof boxes?

EDIT: a local towbar company will charge me $815 (with removable tongue). That's due to there being an additional cost of $365 as they'd have to send it to an auto electrician due to the complexities caused by the LED lighting... Will need to confirm with East Coast that this is taken into account (assume it is, but it's just cheaper due to them having the auto-electrics dealt with on-site).

Inphinity

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#1405667 14-Oct-2015 13:39

You can get a non-branded towbar installed. If they don't use the right wiring harness, there is a chance that a fault in the trailer wiring can cause problems with the car wiring, trigger fault codes, etc, and I have heard of at least a few cases where this has happened and not been warranty covered. But if it's done properly, the risk is low. Some non-dealer-branded towbar places do use the right types of harness and are cheaper than the dealer, so, win win. Personally, I wouldn't be just buying bits from the likes of Repco and hoping it all works out - I'd go to a reputable, professional installer to get it all done.

jonathan18

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#1405668 14-Oct-2015 13:41

graemeh: I have used two brands of roof boxes, Hapro and Thule. I would have just bought the Hapro (I rented one for a trip) but it wouldn't fit under our house for storage so I bought the Thule instead.

If you go with a roof box make sure that it does not interfere with the back door of your wagon.

The Hapro and Thule both seem to be top quality boxes. Phil from "The Roofbox Company" sells on Trade Me as "dudes1" and is great to deal with. They ship the box to you or if you're in Wellington he will fit it to your vehicle. I see they also have an Auckland showroom now so I expect they can provide the same service in Auckland too.

I don't know if the "aerodynamic" roof bars are better than the square ones. I do know if you leave the rubber strip out of the aerodynamic bars you get a nice whistle around 100 km/h. I believe this is a safety feature created by the manufacturer so you don't need to look at your speedo.

When I'm not using the rack I remove it.

Most boxes come with "U" bolts that go around the bar so it doesn't matter too much what bar you have. Some of the brand name bar and box combos use hidden bolts that fit into a slot on the top of the bar.

Renting the box is also an option, you'd probably have to buy the rack though.

Also make sure that you don't get a box that is too wide, you need to be able to reach the back of it while standing in the car door.

Driving with the box on seems to add about 10% to my fuel consumption.

Thanks for the really useful reply; I've seen The Roofbox Co's products on TM; they seem to be the biggest seller of boxes on there. Good advice re width and length - will be sure to check carefully before purchasing!

That 10% additional fuel usage lines up with Consumer's test, which showed an average of 12% - I'm happy to live with that, given it's only for short periods and 10-2% on top of our usual 5.6l/km is not much over 6l... Do the horizontal bars (which I guess are left on all the time) add much to fuel use?

jonathan18

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#1405674 14-Oct-2015 13:47

Inphinity: You can get a non-branded towbar installed. If they don't use the right wiring harness, there is a chance that a fault in the trailer wiring can cause problems with the car wiring, trigger fault codes, etc, and I have heard of at least a few cases where this has happened and not been warranty covered. But if it's done properly, the risk is low. Some non-dealer-branded towbar places do use the right types of harness and are cheaper than the dealer, so, win win. Personally, I wouldn't be just buying bits from the likes of Repco and hoping it all works out - I'd go to a reputable, professional installer to get it all done.

All makes sense... I had no intention of getting the cheapest install, including going down the Repco harness way! It was more that the Repco guy suggested a solution at the extreme from Mazda's advice.

Mazda does do their level best to scare owners into buying the 'official' thing, eg the risks of the incorrect harness (or fitted incorrectly) at https://www.mazda.co.nz/services/mazda-parts-manuals/genuine-trailer-harness and the towbar itself at https://www.mazda.co.nz/services/mazda-parts-manuals/mazda-genuine-tow-bars.

MikeB4

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#1405677 14-Oct-2015 13:52

jonathan18:
MikeB4: I can't speak for roof boxes but I reservations about them. As for tow bars I do not use OEM bars as they are too expensive, I have always used Eastcoast Bars in Wellington as their prices are very good (average $350 installed with electrics). However before installing I get assurance from our car dealer that the install won't impact the new car warranty.

East Coast Towbars does seem to get recommended by lots of people. I've confirmed with them it would cost $450 for a standard towbar on the car, and $480 for one with a removable tongue. They said two bolts would need to be undone to remove the tongue - has anyone had such a towbar fitted by East Coast Towbars, and is that how the removable ones normally work? I'd prefer one that left as little visible on the outside, for both aesthetic and practical (shin-protection) purposes, but also don't want the removal/insertion process to be too big a hassle...

BTW, what are your reservations about roof boxes?

I had one with a removeable ball assembly but it was a pain, it would often rattle a lot. I stick with standard ones now.

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MikeB4

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#1405679 14-Oct-2015 13:56

jonathan18:
MikeB4: I can't speak for roof boxes but I reservations about them. As for tow bars I do not use OEM bars as they are too expensive, I have always used Eastcoast Bars in Wellington as their prices are very good (average $350 installed with electrics). However before installing I get assurance from our car dealer that the install won't impact the new car warranty.

East Coast Towbars does seem to get recommended by lots of people. I've confirmed with them it would cost $450 for a standard towbar on the car, and $480 for one with a removable tongue. They said two bolts would need to be undone to remove the tongue - has anyone had such a towbar fitted by East Coast Towbars, and is that how the removable ones normally work? I'd prefer one that left as little visible on the outside, for both aesthetic and practical (shin-protection) purposes, but also don't want the removal/insertion process to be too big a hassle...

BTW, what are your reservations about roof boxes?

My reservations with roof boxes are....

1. Getting on and off
2. changing the center of gravity for the vehicle and changing its handling characteristics.
3. Getting the loaded weight right for the vehicle and the roof maximum.
4. Increased fuel consumption due to extra drag.

graemeh

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#1405683 14-Oct-2015 14:01

jonathan18: Do the horizontal bars (which I guess are left on all the time) add much to fuel use?

Sorry, I don't know. I remove the horizontal bars when I'm not using them. I mostly use the box during winter for ski trips.

MikeAqua

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#1405685 14-Oct-2015 14:02

We had a thule roof box. We have now sold it and I can't remember which model sorry.

It was mostly great: Light, took tonnes of gear, secure and easy to open/close.

My only criticism was the mounting of the curved claws that grip onto the cross bars. The were hold to the base of the box by much.

If you bumped the claws from the bottom while fitting/moving the box they would come out of their mounts in the underside of the box. I didn't seem to be an issue once they were tightened onto the crossbars but it was a fiddly PITA when fitting.

This particular model was clearance stock in 2008/2009, so the issue may have been long ago resolved.

Mike

MikeB4

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#1405689 14-Oct-2015 14:08

If you are getting a box and of course the rails get the low noise ones trust me you will appreciate it. I have had both types on vehicles and the non low noise ones can be very noisy at times.

It is also a good idea to take them off when not in use, it protects them and reduces any drag although the quiet bars don't really add much to drag. Also makes cleaning the car easier with them off and you cannot go into those god awful car washes with them on.

mdooher

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#1405744 14-Oct-2015 15:21

Not sure about Mazda, but on my vehicle (BMW) plugging in the trailer changes the behaviour of the stability control and alters the gearbox change steps etc. It also allows the trailer lights to be tested as part of the bulb test system.

If your vehicle is designed to do this then you need to find out if it uses a towing module and if it is fitted. Many BMW owners get an auto sparky to install a couple of relays to make the lights work...silly move

Matthew

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#1405752 14-Oct-2015 15:38

I've bought a number of roof boxes but recently only bought the Hapro models from The Roofbox Company. They're solid boxes which can take a bit of a beating for sure. Feel like a good quality product to me, too.

I've also bought a few roof racks to carry said boxes. I've tried both aero (whispbar) and standard square stock models. I can comfortably say that the aero bars are significantly quieter. The fuel consumption hasn't had any affect from the aero bars I don't think.

Some note on roof boxes.
- Many don't open from both sides. This can make life tricky for loading/unloading...
- Look for ones which won't lock if they're not closed properly... It can be a pain if you're really stuffing all the gear into it, and it won't lock without you pulling it down, but that's a small price to pay for not having it spring open in a cross wind at 100 clicks in the middle of nowhere... don't ask...
- The Hapro models come with a universal foot to mount on all sorts of bar sizes. They ratchet closed and are very easy to install/remove but once done up I can't move the box around. They also have a couple of tie downs inside the box which help secure loads inside the box.
- When you install the box, do so with the tail gate open... those gas struts can really provide a lot of force so close to the hinge...
- If you have a shark fin aerial, make sure it doesn't interfere with it, either.
- Most bars aren't rated for more than 75kg each. So if you have two bars, you can really only transport two teenagers in there at a time. It might be easier putting the bags up there.

I don't use a tow bar sorry so can't comment on those.

mdf

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#1405784 14-Oct-2015 16:17

Have a realistic think about what you will use the towbar for.

I was all set to shell out for the full dealer install when I realised that I would hardly ever actual pull a trailer with it, 95%+ of the time it just holds a bike rack. There's really no need for the full electronic jiggery pokery if you aren't even plugging in to the trailer port. Don't forget the supplementary plates though.

For what it's worth, I personally would never dream of taking a trailer on holiday. Towing a trailer is a pain at the best of times, much less on the open road. And I would imagine that a trailer is going to cost you a lot more than the 10 - 12% hit in fuel efficiency that the roof box would.

jonathan18

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#1405785 14-Oct-2015 16:17

Disrespective: I've bought a number of roof boxes but recently only bought the Hapro models from The Roofbox Company. They're solid boxes which can take a bit of a beating for sure. Feel like a good quality product to me, too.

I've also bought a few roof racks to carry said boxes. I've tried both aero (whispbar) and standard square stock models. I can comfortably say that the aero bars are significantly quieter. The fuel consumption hasn't had any affect from the aero bars I don't think.

Some note on roof boxes.
- Many don't open from both sides. This can make life tricky for loading/unloading...
- Look for ones which won't lock if they're not closed properly... It can be a pain if you're really stuffing all the gear into it, and it won't lock without you pulling it down, but that's a small price to pay for not having it spring open in a cross wind at 100 clicks in the middle of nowhere... don't ask...
- The Hapro models come with a universal foot to mount on all sorts of bar sizes. They ratchet closed and are very easy to install/remove but once done up I can't move the box around. They also have a couple of tie downs inside the box which help secure loads inside the box.
- When you install the box, do so with the tail gate open... those gas struts can really provide a lot of force so close to the hinge...
- If you have a shark fin aerial, make sure it doesn't interfere with it, either.
- Most bars aren't rated for more than 75kg each. So if you have two bars, you can really only transport two teenagers in there at a time. It might be easier putting the bags up there.

I don't use a tow bar sorry so can't comment on those.

Great feedback, thanks. I'll investigate the Hapro brand further tonight.

You mention this brand works with a range of bar sizes - I'm assuming this includes the Whispbar range? I'm thinking of this particular model, given our car has the side rails on already - http://www.whispbar.co.nz/products/11/rail-bar

Are there any other brands of bars that offer a similar aerodynamic profile that anyone would recommend?

Good point re shark-fin aerial; ours has this so will be careful. And, as for the kids, ours are 4 and 8 so there's no issue there - indeed, if that's a 150kg total weight limit I imagine I'll be able to fit some of their friends in there too - who needs a seven seater?

Cheers
Jonathan

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