Maximum recommend speed with bike on roof rack

General cycling advice ( NOT technical ! )
ndwgolf
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Maximum recommend speed with bike on roof rack

Postby ndwgolf » 5 Oct 2018, 7:23am

I planning on taking my new Trek Madone 7 from my home in Kuala Lumpur Malaysia to Phuket Thailand...... It's pretty much highway all the way with a maximum speedimit of 110 kh (70 mph). I will be using a Thule roof rack on the back of my pick up truck so half of the bike is protected from the wind due to the cab.
My feelings is I should be okay at 110 to 120 kph.....but wondered if anyone has any other ideas.
Neil

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meic
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Re: Maximum recommend speed with bike on roof rack

Postby meic » 5 Oct 2018, 7:26am

Fuel consumption will rise very markedly the faster that you go.
The bike will make a real impact on fuel consumption raising from 50mph to 70mph on top of the existing large difference between the two speeds.
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hayers
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Re: Maximum recommend speed with bike on roof rack

Postby hayers » 5 Oct 2018, 7:59am

I think my roof carrier specifies 60mph max speed in the manual - but it's been fine at 70... fuel use does go up but tend only to use the carrier when well loaded up for family or group trips so that will be part of the increase.

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gaz
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Re: Maximum recommend speed with bike on roof rack

Postby gaz » 5 Oct 2018, 8:07am

ndwgolf wrote:It's pretty much highway all the way with a maximum speedimit of 110 kh (70 mph). ...
My feelings is I should be okay at 110 to 120 kph.....but wondered if anyone has any other ideas.

I've got another idea. The speed limit is a maximum, not a target to be exceeded. Drive at a speed within that limit that is safe for the road conditions you encounter.

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100%JR
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Re: Maximum recommend speed with bike on roof rack

Postby 100%JR » 5 Oct 2018, 12:18pm

My old Mont Blanc Barracuda stated 75mph.They were fine at speeds well in excess of that but obviously got noisier.I had them on various cars for about 7 or 8 years and did 1000's of(as it turned out expensive) miles without issues.
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brynpoeth
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Re: Maximum recommend speed with bike on roof rack

Postby brynpoeth » 5 Oct 2018, 12:30pm

I always dismantle my machine (remove front wheel, takes a few seconds) and put it inside the vehicle
Putting cycles on the back or on top of a vehicle is very precarious, the belts or clips holding them could easily loosen through vibration and wind speed, bikes could fall off and cause (?) serious "accidents"

Plus One for keeping comfortably below the maximum speed limit :)
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brynpoeth
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Re: Maximum recommend speed with bike on roof rack

Postby brynpoeth » 5 Oct 2018, 12:31pm

Plus One for keeping comfortably inside the maximum speed limit :D
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Shuggie
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Re: Maximum recommend speed with bike on roof rack

Postby Shuggie » 5 Oct 2018, 12:42pm

brynpoeth wrote:Plus One for keeping comfortably inside the maximum speed limit :D


thirdcrank
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Re: Maximum recommend speed with bike on roof rack

Postby thirdcrank » 5 Oct 2018, 12:57pm

AFAIK, Thule include maximum advised speeds in their instructions. If you haven't got the instructions they are all online AFAIK. Apart from the obvious issues of fuel economy and noise, you are into peace-of-mind territory. Nobody can really give you that. The strength of the wind resistance at motorway speeds is considerable. A couple of years ago, before I bought my own Thule bike carriers, I nearly lost a bike off a roofrack on the A1. It was an old Paddy Hopkirk rack and the clamps holding the bike carrier had been badly bent and luckily, an overtaking driver waved at me and pointed at the roof. I mention the fact that it was an overtaking driver to show I wasn't going particularly fast

MikeF
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Re: Maximum recommend speed with bike on roof rack

Postby MikeF » 5 Oct 2018, 1:11pm

Drag is proportional to the square of the speed, ie it is almost twice as great at 70 mph than 50 mph.
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Audax67
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Re: Maximum recommend speed with bike on roof rack

Postby Audax67 » 5 Oct 2018, 1:44pm

MikeF wrote:Drag is proportional to the square of the speed, ie it is almost twice as great at 70 mph than 50 mph.


As you will notice when you take your foot off the accelerator.
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Phil Fouracre
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Re: Maximum recommend speed with bike on roof rack

Postby Phil Fouracre » 5 Oct 2018, 4:31pm

Don't know about max speed, but, don't go on a car ferry and forget you've got it on - saw a guy do this years ago, bet it cost him a fortune :-(
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brynpoeth
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Re: Maximum recommend speed with bike on roof rack

Postby brynpoeth » 5 Oct 2018, 4:35pm

Phil Fouracre wrote:Don't know about max speed, but, don't go on a car ferry and forget you've got it on - saw a guy do this years ago, bet it cost him a fortune :-(

Should have been wearing a h****t :?
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Nigel
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Re: Maximum recommend speed with bike on roof rack

Postby Nigel » 5 Oct 2018, 6:31pm

ndwgolf wrote:I planning on taking my new Trek Madone 7 from my home in Kuala Lumpur Malaysia to Phuket Thailand...... It's pretty much highway all the way with a maximum speedimit of 110 kh (70 mph). I will be using a Thule roof rack on the back of my pick up truck so half of the bike is protected from the wind due to the cab.
My feelings is I should be okay at 110 to 120 kph.....but wondered if anyone has any other ideas.
Neil


No idea about your roads. But I recently took two bikes 300+ miles in the UK whilst visiting friends. I took a roof bike carrier, but for the long trek I dismantled the bikes to carry inside the vehicle. At the destination, shorter runs were done with bikes on the roof to save the time/hassle of removing pedals, wheels, seatpost, turning handlebars, carefully stacking with protective padding, etc..

brynpoeth
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Re: Maximum recommend speed with bike on roof rack

Postby brynpoeth » 5 Oct 2018, 6:50pm

A folding cycle need not cost much and fits easily inside the vehicle

Cycles on top or on the tailgate looks really "dangerous" to me
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