UKC

Ok. So I followed all the advice and bought the right car. Yes that one. Now I need to move 4 proper size bikes, and a roofbox.. for a two week trip to the farthest bits of Scotland, including ferries of various sizes.

what’s the best option? My saris bones rack only does 3.. so I either need a new rack solution for the back or put one on the roof vertically? Can you do this with an offset roof box? Any other suggestions out there? What works best. Tow bar racks have always sounded sketchy to me but I guess they can’t be…?

Tow bar racks are the absolute best. And they’ve gotten significantly better since I used one. They’re pricey but OMG getting 4 bikes on a roof? Stuff of nightmares. Get yourself a Thule 3 bike rack and add the extension. Well worth the investment.

Edit. This one 

https://www.roofbox.co.uk/scripts/rbvehsel4_tab.php/car-specific-accessorie...

Yea, you’d get to destroy 3 more bikes when you drive under a 7’6” height bridge.  Just saying, cough, cough

Towbar rack every time - solid, easy to load and still get access to the boot. Better on fuel too I suspect.

Thule Euroclasic off eBay along with the fourth bike add-on has been one of my best purchases ever, and the quality is good enough to last me at least another decade yet.

LOL. My mate did the same. The bike was fine but the rack bent to buggery....go figure....

Thuel tow bar all the way. 

Be aware though your reverse sensors won't like it (unless things have changed since I last used one) 

Depending when bikes you are putting on it you might find it affects the handling of the car. Electric bikes can be quite heavy (if they are your thing) and you could put more weight on the back of your car than the nose weight of a trailer. 

Ok.. given I don’t actually have a tow bar that option looks like it’ll be about £1200! My car probably is only worth that these days. Ouch.

I did warn you. You could try a mix of two on the top and two on a back rack?

Yeah I was thinking 3 on the back on my saris and one on the roof next to the roofbox. Would that work/be legal with the roofbox too? (I wasn’t imagining all 4 on the roof!)

I def seen it done. So can't imagine any legal issue.

Edit. Link

https://support.roofbox.co.uk/hc/en-gb/articles/4408452254354-Can-I-fit-a-r...

I have 4 bike racks on the roof of our car. We replaced the saris rs for this option due to the suspension on new bikes not fitting well with saris.

I tow bikes in work on a Thule tow rack and it is much easier. Less core strength needed! Or watching out for low branches.

But like you, I can’t justify adding a tow bar to on old car.
 

Oh and to answer about the roof box. I can fit 2 bikes and a half sized box on the roof comfortably. 
 

I have a berlingo, which is slightly wider than an average car though. 

If you can top tube hang the bikes, I'd recommend a Buzz rack.

Picked up a four bike one a couple of months ago for a good price and seems a lot more sturdy than the thule equivalent. 

You suspect wrong. Tow bar rack really messes with the airflow off the back of your car, whereas a modern bike is pretty aero if you align it with the direction of travel.

I presumed you're opposing them already, as bikes don't mind not facing forwards? 4 will fit on a normal car. 

Is there a study on this as it's an interesting topic.

My guess would have been rear mounted is more aerodynamic as your not increasing area, just the drag coefficient.

Mounting up top you're increasing the area and the coefficient as bikes have appalling coefficients compared to cars.

You may be right but I wouldn't put money on it.

What I would say is I have three bikes on a tailgate rack last week as it seemed super sketchy. I had it mounted high as I didn't have a spare numberplate so weight was on the glass and I didn't like it. It also backers the paint especially where hooks attach. I would mount four that way.

I still have three mounts that fit to roof bars but stopped using them as it was so much effort.

In my pursuit to try all bike racks in existence a tow bar mount is next and I suspect it will solve all my bike carrying problems.

I did wonder on this. I use my towbar one a lot and notice a drop in fuel economy, but also see a drop when I use the roof one. I've never really worked out much of the drop for the towbar one is attributable to drag or the fact the car switches from eco-mode to something else when the towbar electrics have anything plugged in. I much prefer the towbar route though.

A friend managed to write off her mothers car by driving into a car port with bikes on the roof. It damaged the roof structure and potentially compromised the safety of the cabin.

Thing is, do we also drive differently when we have bikes attached to our cars? Faster in anticipation of getting there? Faster as still buzzing from a great day out? There’s definitely a good study to be had on the subject, but you’d need to ensure plenty of control measures to evidence anything worthwhile.

I think things have changed.  On my 2017 Yeti with aftermarket towbar and detachable tow ball, the car detects when a light board is plugged in to the 13-pin socket on the towbar and disables the reversing sensors.  (I believe it also tweaks the various electronic stability aids to take into account the slightly altered weight distribution, but that's not something you would notice in everyday driving.)  I believe the onboard computer(s) had to be configured* to recognise when it's towing, as that functionality isn't enabled as standard (though you can get it as an option if you are buying new), but it's straightforward, documented stuff and the towbar fitter handled it as part of the job.

This applies to anything hitched to the tow ball, not just bike racks.  Fairly obviously...

Old-style 7-pin towbar electrics might well not have been as sophisticated, though.  (May also be the case if you are using a 7-pin light board through a 13-pin to 7-pin adaptor.)

* Probably little more than setting a bit somewhere from 0 to 1!

There’s this test, which isn’t exactly a peer-reviewed journal article but seems reasonable to me and agrees with your guess:

https://www.consumerreports.org/fuel-economy-efficiency/how-bike-racks-affe... 

ianstevens seemed very confident in his view so perhaps he has access to a more rigorous test result. 

How much are the bikes worth, though?  My tow bar and rack cost about ⅓ the cost of my eMTB, which I thought was well worth it to avoid having to hoik the flippin' thing up on to a roof mounted rack.   Thinking also about the horror stories above concerning incompatibilities between rooftop bike racks and height restriction barriers...  

A pal once did the driving-under-a-height-restriction sign/barrier trick.  The bike was actually OK - perhaps more by luck than design (I think either the attachment of the roof rack to the car, or the bike rack to the roof rack failed first) - but car spent the rest of its life with a sizeable dent in its roof.  The sign was at the entrance to an open-air shopping centre car park which of itself did not have any physical headroom limitations.  The barrier was just there to stop trucks and other kinds of commercial vehicles from using the car park, and the signage was very easy to miss if you were driving an ordinary car and had forgotten about the load on the roof.

I used to carry bikes on a roof-mounted rack on my lovely three litre Subaru Legacy. The clamps holding it onto the roof weren’t great and one day the whole rack flipped up like a toupee in a headwind. That dinged the roof in a couple of very awkward places that weren’t economical to repair.

So for cars without roof rails I’ve switched to a tow bar mounted rack. It’s marginally slower to take the bikes off or put them back on again, which unfortunately makes all the difference in some midge-infested Highland car parks. Other than that minor issue it’s great and is surprisingly secure.

I’ve also tried one that hooked onto the tailgate on a hatchback but I never trusted it and saw plenty with loose straps  

I have an older version of the Atera Strada 3 bike towbar carrier. The newer version (£590 from the Roofbox Company) has an optional adapter for a 4th bike:

https://www.roofbox.co.uk/scripts/rbvehsel4_tab.php/car-specific-accessorie...

It's a good bit of kit and well made. It has an extender enabling access to the tailgate with the bikes attached. It can easily cope with 2 electric bikes with batteries removed, so weight isn't a problem. The downside is that the car's reverse sensor doesn't work.

How much? Significantly less than yours.. all manual, 2 carbon road and 2 hybrid/junior road. mostly 2nd hand/old. Worth to sell.. bugger all. worth to replace with new at a bike shop.. a fair whack I guess but I wouldn’t do that even in the event of a bridge!

Thanks all. Think I’m sticking with the 2/3 on the boot and 1/2 on the roof with the box solution for now. Tow bar is probably the best way but on this car which doesn’t have one it’s too expensive for now.

On my Peugeot 308, I can get a narrow roof box and two roof mounted bikes either side.

No issues with legality.  I do it all the time.

Here is my setup: 

• I've got a single Thule ProRide on the roof year round - inc when I have the roof box on.  That's what I use when I'm riding by myself or meeting friends.  Assuming you're tall enough .. its a breeze to put a bike up there and very fast.  < 1 min.  
• I have a tow bar and Thule VeloCompact 3.  It's fantastic and shove it on for > 2 bikes.  As others have rightly said ... many cars reversing sensors get upset but a minor inconvenience at most.   Imperative that you get one that still allows you into the boot - some of the older/cheaper ones do not and it's a massive pain when you (and you will) leave something in the boot before putting the bikes on.   

Re:  Thule prices.  All Thule kit is expensive - definitely fair criticism - you're paying for the Thule brand name.  However - their kit is good and you can buy spares (also expensive!) if you break something on it.  

Re:  Tow Bars ... you pay more for removable vs immovable and hence could save if you put on an immovable one.  On my next car I'm going to fit a immovable swan neck for no reason other than A/ I don't really care about the aesthetics of having the tow bar poking out year round and B/ gives you protection from either you backing into something or someone backing into you. 

Re: Rubbing.  Need to be quite careful when you mount the bikes on a hitch mount rack because they are at risk of rubbing.  Annoyingly .. the bikes never go on the way they came off - it's a puzzle every single time (I can't explain this).  Sponges, pipe insulation and velco or removable zip ties are good options if you think the bikes are going to rub.  (If they rub .. they will rub right through the paint to the bare metal).

I'll be honest .. I'm not a massive fan of the tow bar mounted bike racks left on the car when not in use.  I'm paranoid about where I park with them on for 2x reasons:  1/  I get constantly worried about someone backing into me and damaging the bikes, the rack and the car in a oner - $$$$ (probably more worried about the bikes).  That usually means picking wisely in retail parks etc .. and 2/ Theft.  I don't know why I worry more about theft on the tow bar than on the roof but I do and I put a very large & very visible lock and shackle on the bikes on the back in the (naïve?) hope that it might say to someone "go and try stealing someone's bikes .. these one's will be pain". 

That probably brings you onto the question of where to store your hitch mount bike rack - they're a fair size and ~20kg.  I hang mine on the wall of the garage on ladder hooks - gets it off the ground and out of the way of being damaged.  Important that you store it somewhere that you can get it on/off the car easily or it defeats the purpose a little as you'll use it less.

I've never regretted the tow bar .. but price is fair criticism.  Either buy a car with one on already (but then you run risk that they've regularly towed something heavy with it) or you buy a car with an intention to own for more than the normal 3-4(?) years before replacing ... and that way you get better ROI.  

Tell us what you decide to do.

Don’t know what kind of bike you have but the CDA of mine is waaay below that of my car. And it’s not about frontal area, it’s all about drag coefficient (part of which is frontal area, but a large part is air leaving surfaces - your car is optimised for this, which is then destroyed when you place a selection of wide objects across the air path, inducing a load of extra turbulence (aka drag).

I’d guess the equation is shifted with a city bike or MTB, which aren’t that aero, but a modern road bike with deep wheels on the roof seems to make less difference (in my uncontrolled experience). That said, unless you have a light bike and a low car, getting it on the roof is a PITA, and you have to watch out for height barriers. 

Most cars are not optimised for this, aesthetics and practically trump aerodynamics for most cars, if cars were routinely optimised for aerodynamics they would look much more like the Volkswagen XL1 or the Aptera. For a sedan style car, your theory is likely to be right, as a lot of the bike will be outside of the low pressure zone and increasing the frontal area of the car more than if it was on the roof, but for a Land Rover, Citroen Berlingo, or any other large boxy car your theory is unlikely to be right as the bike would not be increasing the frontal area at all and the area behind such a car is going to be pretty turbulent anyway. I wouldn't go stating unequivocally that it is always mount the biker on the roof without a decent study to back it up as IMO it is highly unlikely to be correct in many if not the majority of cases.

I have an MTB. CdA for a bike will always be lower as it has a smaller area, but just looking at the drag coefficient, bikes are generally much higher than cars.

The Cd for a Scoda Octavia varies, but 0.25 is the right ballpark.

According to this: https://www.reddit.com/r/bicycling/comments/m6sal/drag_chart_for_different_... cD bike a generic bike with no rider is 1.1.

Not sure what you mean by this. Surely it's both, in equal proportions. Double the Cd you double the drag. Same for the frontal area.

I run out of knowledge here as I have no idea how much the Cd of a car is changed by adding bikes to the back. 

Adding a bit of real life experience (aka totally unscientific anecdotal evidence):

We have a towbar rack and roof carriers.  They each have a similarly horrible impact on the fuel consumption of our estate car when used separately.  So there does seem to be something about the aerodynamics.  On the odd occasion we’ve used both together, it doesn’t seem to make things much worse.

On our van, the towbar rack seems not to have much effect at all.  But with bikes on the roof, you can almost see the fuel gauge moving.  (Plus you have to carry a stepladder.)

Trailer hitches are cheap and really easy to install yourself especially if you have a friend help hold it. I've done 3 and I'm mechanically useless. The racks are expensive though but they're also usually much better built than other types of racks, mine is as good as it was new and I've had it 10 years. 

Edit: never mind it seems like you can't use receiver hitches in the UK. Which is a shame they are far superior for accessesories like bike racks.

As usual the Germans have tested this (on some utterly boring middle-class SUV) for the tow-bar mount the fuel consumption increase was 3,5%, for roof-rack mount it was 24.6% and for ones hung on the rear door 22.8% at 100km/hr (like I said, a boring SUV with an equally boring driver). Jerk it up to at least retired dodderer speed (130km/hr) and it's 6,3%, 34,2% and 44.3% respectively. Mercedes and Porsche test this stuff as well!

Ah, 'Four Bikes In One Car', that classic by Crowded Boot...

The thread title makes me want to sing a parody of Three lions on the shirt...

• 4 bikes on the car
• how we going to do this
• roof mount or tow bar
• must be solid not hit or miss...

You might change your mind on that after you've wacked your shins on it a few times struggling to put something in the boot.  (Speaks from experience, with the scars to prove it!)

Question to the UKC hive ... do you remove your removable tow bars? 

I don't.  I just leave it there year round with a hitch ball cover on it.  The few times I have removed it ... it gave me a bit of hassle getting it back in again with grit on the thread/in the receiver etc...  didn't bother removing it after that.

I had a removable one on my Seat Leon, and left it in place. On my Skoda Octavia it's a fold-away one, and I do fold it back under the bumper when not in use. Mostly because I like the solid clunk it gives when folding away or being put into use...

Of course you are right - I was assuming a non-box car, which is the exact opposite of most modern vehicles.

When I had one, yes. Made a very nice car look ugly. 

Depends on the towing hitch electrics I think. The one with more pins disables the sensors, the one with less pins doesn't and you need to diable them via the car settings (or put up with constant bleeping).

For the first time ever, I have a car that doesn't currently have a tow bar fitted, and I like the look of it without one. So if I do choose to get one fitted, I'll probably swallow the extra cost and get a removable/folding one. All my other cars have had the old, fixed two bolt types. Having said that, I know I'd get lazy and just leave it in place most of the time!

Yep, that’s exactly what I’ve done.

If you put a bike on the roof, put a sticker on the steering wheel to remind you about your increased height, saves a lot of drama..................

Yes. They’re all full suspension bikes with wide handle bars and unforgiving pedals, so a bit of jiggery pokery when initially putting the racks on. But fine now

I had one on a BMW estate, I only ever fitted it when I was carrying bikes which wasn't that often. The reversing sensors didn't like it though this was a while ago, they've probably come on a bit since then.

Regarding fuel consumption, the tow bar rack with bike reduced MPG from about 40 to 35-36. I now have an Octavia and carry bikes on the roof. MPG goes from 60 to 50. I don't drive any differently with bikes on, if anything I drive slightly more gently. 

At 3.5%, I might be tempted to buy one of those SUVs!

(Only joking)

I can feel your pain. A colleague did exactly this, destroyed a few pretty expensive carbon fibre bikes by not noticing a height‑limited bridge, and it certainly hurt. A fecking lot.