Roofbars

bikeit65

Looking recomendations for roofbars and bike holder? Thanks

imposter2.0

Give us a clue - what type of car?

bikeit65

I suppose that would help, Mazda 3 hatchback, only need it to carry one road bike

lostboysaint

Are you leaving them on the car? If yes then Whispbar are by far and away the best. No noise, no reduction in fuel consumption and significantly better than any other "aero" bar I've ever used.

This'll give you a good idea of choices, they also do package deals with bike carriers as well. https://www.roofbox.co.uk/scripts/rbvehsel3.php?query=7744&emulate=roofbar&vptype=421927

Craig_Broadbent

lostboysaint wrote:

no reduction in fuel consumption

I don't think so.
RAC estimates 10% fuel burn increase.
https://www.rac.co.uk/drive/advice/how-to/fuel-saving-tips/

svetty

Craig_Broadbent wrote:

lostboysaint wrote:

no reduction in fuel consumption[

I don't think so.
RAC estimates 10% fuel burn increase.
https://www.rac.co.uk/drive/advice/how-to/fuel-saving-tips/

[/quote]
Certainly will be some increase but 10% seems a lot for an 'empty' bar in mixed/urban driving - perhaps this is at motorway speeds?

lostboysaint

Craig_Broadbent wrote:

lostboysaint wrote:

no reduction in fuel consumption

I don't think so.
RAC estimates 10% fuel burn increase.
https://www.rac.co.uk/drive/advice/how-to/fuel-saving-tips/

RAC can ESTIMATE what it likes. I have the before and after figures for several cars with Whispbars fitted and they make no difference whatsoever. I suspect my sample size, mileage and methodology are significantly more robust than theirs.

I made the move to them after being disappointed with the noise and fuel consumption increase on other big brand name "aero" bars and having them recommended.

figbat

lostboysaint wrote:

RAC can ESTIMATE what it likes. I have the before and after figures for several cars with Whispbars fitted and they make no difference whatsoever. I suspect my sample size, mileage and methodology are significantly more robust than theirs.

I made the move to them after being disappointed with the noise and fuel consumption increase on other big brand name "aero" bars and having them recommended.

They will make a difference. Because physics. At the very least they add mass to the car, which will need more energy to accelerate. They also, regardless of their cross-section profile, add aerodynamic drag to the car. The impact of this will be driven by the drive cycle being used, with a greater impact at higher speeds.

They may make no noticeable difference, but this may speak as much about the large number of variables and the precision of the measuring than it does about their ability to defy fluid dynamics (by the way, I work in a field where precise measurement of fuel economy is a key activity). Whispbar themselves show that their bars generate drag:



Back to the OP - I use Thule Wingbars and a Proride 598 rack - quick and easy to put the bike in and out and I haven't lost one yet. The only thing to mention is that it clamps the sloping tube - if you have external cables routed down here then you'll need to consider frame protection options to prevent the cables rubbing the paint when clamped (I used an old bit of inner tube between the cables and frame).

Oh, and by the way, I would also recommend Whispbars - seriously, despite the above diatribe, I do rate them.

lostboysaint

5.6kg/2224kg = what, shall we say 0.2%? Mass, good one.

The aerodynamic profile is, as you say, the more relevant issue and of course it will do something but again, against a frontal area with what drag coefficient?

That'll be why in over 50k miles there's absolutely no noticeable difference in fuel economy on at least two different vehicles. (several thousand in the one with the weight quoted above - and for the benefit of the doubt, I've quoted the lighter of my two vehicles.)

See, two people can be pedantic tw@ts!

3wheeler

Your main choice will be the Mazda ones, or other brand: wispbar, thule wingbar .... thule has the benefit that you can get different adaptors to fit them to another car in future, but they're expensive to buy new and the adaptors are expensive so I'm not sure how much of a benefit that is.

Most of the 3rd party ones use the same attachment slot for fixing accessories onto them.

BTW RAC 10% is complete cr@p - on my last car in the real world I couldn't tell any difference so maybe 1 or 2% at worst.

figbat

Oooh, pedantry; now we've wandered right into my area of specialism.

5.6kg/2224kg = what, shall we say 0.2%?

OP drives a Mazda 3, not a Challenger tank. 5.6kg/1,400kg, let's call it 0.4%. If you offered a car OEM a reliable 0.4% fuel economy improvement, they'd take your arm off. Even your 0.2% would raise eyebrows. That assumes that FE correlates directly to vehicle mass, which isn't the whole truth of course, but OEMs are making stuff like spare wheels optional to save a few kilos and get better mpg and CO2 numbers (and spare wheels usually add no aero drag).

And I'm guessing if you are driving 2+ tonne cars, they will make quite a dent in the air, to which roofbars might not add much. A svelte Mazda hatch will start with a better Cd and therefore have more to lose with sticky-out bolt-ons.

So, in summary, Whispbars.

figbat

By the way, just to be clear, I also doubt the RAC 10% claim. But I don't doubt it all the way down to 0%.

Matthewfalle

mf has Volvo ones on the Honda: he thinks they are made by Thule.

15 years use, work perfect, 30 seconds to put up bikes/take off bikes.

no idea re fuel consumption because he really doesn't care.

figbat

MF is correct, the Volvo stuff is made by Thule and is identical save for the branding (this goes for their towbar racks too).

ayjaycee

I can't really recommend any from personal experience as mine came with the car and are specific to it's rails but I do remember that earlier this year I was browsing a copy of Auto Express in WH Smiths Paddington and saw a test of various roofbars. I can't rememer any of their recommendations but all of their tests are available to read on the website. Go here: http://www.autoexpress.co.uk/accessories-tyres and search for Roof Bars and / or Roof Rails for the tests.

Craig_Broadbent

Enjoyed the Aero Fuel economy debate. Expert vs ...
I used to work for a big/now biggest car manufacturer.
We would spend a lot of money saving a fraction of the losses that you are putting back on by adding a roof rack and we hated to spend money on things the customer couldn't see.
I see lots of clutter left on roofs throughout the year. This is a fuel economy and a global warming nightmare.
In the USA, they reckon that the roof rack mess will soon add 1% to total fleet fuel burn. That's a lot of carbon, so those of you who care for the planet may want to decline, or at least take it off when not in use.
http://newscenter.lbl.gov/2016/04/25/roof-racks-drag-fuel-economy/
Please note title it may be costing you 25% extra fuel burn.
I suspect many people leave the bike racks on, so the saving by adding Aerobars may be a sop.