Cycle roof rack failure

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landsurfer
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Joined: 27 Oct 2012, 9:13pm

Cycle roof rack failure

Postby landsurfer » 3 Aug 2017, 10:23am

2nd of August, southbound on M1, Julie shouts "BIKE" at the top of her voice.
I glance sideways to see my TREK swinging alongside her window !!!!!
On to the hard shoulder and gently to a stop.
The clamp on the rack that holds the downtube has snapped allowing the bike to fall sideways, the rear wheel strap has ripped the wheel track and come free and the front wheel is still attached to the wheel track but has distorted it.

The saviour of the day was the Poundland cable lock that i always attach between the bottom bracket and the roof bar across the car.

Amazingly no damage to the bike or car ..... rack wrecked ....

Rack was Halfords Essentials, 2 years old .... £24. Replaced with THULE 598 ....£CONSIDERABLY MORE !

Julies heart beat returning to normal with the help of Gin.
Be More Mike.
The Road Goes On Forever

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gaz
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Location: Kent, lorry park of England

Re: Cycle roof rack failure

Postby gaz » 3 Aug 2017, 10:37am

Eeek :shock: .

How were you able to continue the journey?

Any thoughts on how the failure occured?
There'll be tarmac over, the white cliffs of Dover ...

landsurfer
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Joined: 27 Oct 2012, 9:13pm

Re: Cycle roof rack failure

Postby landsurfer » 3 Aug 2017, 10:47am

gaz wrote:Eeek :shock: .

How were you able to continue the journey?

Any thoughts on how the failure occured?


Took the wheels of the bike and put it on the rear seat.
The bike is held vertical by 2 rods clamped with a bolt between them the end of one of the rods snapped off.

http://www.halfords.com/cycling/bike-ra ... le-carrier

One of the 2 rods / tubes that hold the bike vertical snapped at the clamping point.
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MikeF
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Location: On the borders of the four South East Counties

Re: Cycle roof rack failure

Postby MikeF » 3 Aug 2017, 11:04am

Lucky you weren't on a "Smart" Motorway!!

I was on a motorway (M23) when ladders fell off a roof rack of a vehicle a short distance in front. I didn't see exactly what happened as my view was obscured by an articulated lorry in front which I realised was braking heavily and pulling onto the hard shoulder, behind several other cars as I found as I passed. I was driving a Land Rover and trailer at about 55mph and a little way back. I also braked, but the lorry pulling off revealed the two outer lanes blocked with damaged cars, and just the inner lane clear, which I was using. The fact I had just driven through a big pile up, that had happened a second or so in front of me I found quite alarming. :shock:

Even now the sight of ladders or similar attached to the roof of cars makes me uneasy.
"It takes a genius to spot the obvious" - my old physics master

landsurfer
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Joined: 27 Oct 2012, 9:13pm

Re: Cycle roof rack failure

Postby landsurfer » 3 Aug 2017, 11:08am

MikeF wrote:Lucky you weren't on a "Smart" Motorway!!


I was.... Junction 27 M1. ...
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MikeF
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Location: On the borders of the four South East Counties

Re: Cycle roof rack failure

Postby MikeF » 3 Aug 2017, 11:12am

landsurfer wrote:
gaz wrote:Eeek :shock: .

How were you able to continue the journey?

Any thoughts on how the failure occured?


Took the wheels of the bike and put it on the rear seat.
The bike is held vertical by 2 rods clamped with a bolt between them the end of one of the rods snapped off.

http://www.halfords.com/cycling/bike-ra ... le-carrier

One of the 2 rods / tubes that hold the bike vertical snapped at the clamping point.
I've noticed sideways oscillations of some bikes on the roofs of cars. Seems like this was happening in your case and was the cause of metal fracture. Perhaps Halfords should be made aware of this.
"It takes a genius to spot the obvious" - my old physics master

MikeF
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Location: On the borders of the four South East Counties

Re: Cycle roof rack failure

Postby MikeF » 3 Aug 2017, 11:28am

landsurfer wrote:
MikeF wrote:Lucky you weren't on a "Smart" Motorway!!


I was.... Junction 27 M1. ...
"Smart" motorways don't have hard shoulders but occasional refuge areas. Parts of the M25 are like this and the M3 near to its junction with the M25. However here there is a "temporary" 50mph limit which seems to work quite well; vehicles seem to stay in lanes.
"It takes a genius to spot the obvious" - my old physics master

fastpedaller
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Joined: 10 Jul 2014, 1:12pm
Location: Norfolk

Re: Cycle roof rack failure

Postby fastpedaller » 3 Aug 2017, 2:39pm

If I see bikes being carried on a vehicle in front (roof or tailgate), I make sure I get in front of it or a LONG way back! Only safe place for bikes is inside.

landsurfer
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Joined: 27 Oct 2012, 9:13pm

Re: Cycle roof rack failure

Postby landsurfer » 3 Aug 2017, 2:42pm

Fortunately Mick this happened AT Junction 27 and we where able to cross onto the entry slip road, which had a hard shoulder ..... but good point ... another 100 yds and we would have been stopping traffic.
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100%JR
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Joined: 31 May 2016, 10:47pm
Location: High Green,Sheffield.

Re: Cycle roof rack failure

Postby 100%JR » 3 Aug 2017, 4:09pm

MikeF wrote:
landsurfer wrote:
MikeF wrote:Lucky you weren't on a "Smart" Motorway!!


I was.... Junction 27 M1. ...
"Smart" motorways don't have hard shoulders but occasional refuge areas. Parts of the M25 are like this and the M3 near to its junction with the M25. However here there is a "temporary" 50mph limit which seems to work quite well; vehicles seem to stay in lanes.

Yes they do.
There are three types of Smart Motorway.
Controlled:-
multiple lanes, variable speed limits and a hard shoulder for use in emergencies only.
Hard shoulder running:-
variable speed limits and a hard shoulder that can be opened as a running lane at busy times. Overhead signs tell you when you may drive on the ‘hard shoulder’M42, M1, M6, M4 and M5.
All lanes running:-
variable speed limits, no hard shoulder, and emergency refuge areas every 2.5km M25 J23-27, M25 J5-6/7
The M1 between Nottingham and Sheffied now has all three types.I know this because it was pointed out on a recent Speed awareness course.

@Landsurfer.We had a similar incident on my friends car but my bike fell right onto his.I'm not sure if they were the same carriers but he works at Halfords and got his exchanged despite them being a few years old.

thirdcrank
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Joined: 9 Jan 2007, 2:44pm

Re: Cycle roof rack failure

Postby thirdcrank » 3 Aug 2017, 4:13pm

There are plenty of vids online showing tests of roof- and rear-mounted bike racks. Many seem to be films of German crash tests but the pictures speak for themselves, no matter what language the commentary is in. Thule kit always seems to come out well.

Here's one at random.

https://www.youtube.com/watch?v=pc6Lh52JTbo

Rear racks at the beginning, roof racks towards the end.

landsurfer
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Joined: 27 Oct 2012, 9:13pm

Re: Cycle roof rack failure

Postby landsurfer » 3 Aug 2017, 10:42pm

MikeF wrote:I've noticed sideways oscillations of some bikes on the roofs of cars. Seems like this was happening in your case and was the cause of metal fracture. Perhaps Halfords should be made aware of this.


In my experience the sideways oscillations often seen are as a result of the lower pivot bolts wearing, allowing play in the support struts.
But in this case i have always monitored the play at the strut base.
The stress vector in this case is the through bolt.
The strut failed / fractured at the point the bolt passes through the support strut.
Repeated excessive compression of the joint would have led to witness marks and possibly damage to the frames of the bikes i have carried.
I believe the repeated low level compression of the joint led to the stress failure, which is worse than excessive stress as it's insidious and counter intuitive.
I have been to Halfords to-day and noticed the rack has had a change from a single compression bolt to a twin compression bolt set up ....

I think Halfords already know of the failure mode ...... but no recall ..... saved a fortune ..... :roll:
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Brucey
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Joined: 4 Jan 2012, 6:25pm

Re: Cycle roof rack failure

Postby Brucey » 3 Aug 2017, 11:35pm

most vehicles are capable of casting a 'vortex street' behind them as they go down the road. Obviously large vehicles cast bigger, more energetic vortices. In motorway traffic these tend to throw everything bolted to a car roof from side to side, even if the bikes themselves don't want to 'flutter' (which they often do; if your car is also shedding vortices these will cause everything back past a certain point on the roof to see a reaction load too ).

Anyroadup, most bike roof racks see quite a lot of cyclic loading. I don't think I ever saw one that I trusted entirely.

cheers
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~~~~~~~~~~~~~~~~~~~~~~Brucey~~~~~~~~~~~~~~~~~~~~~~~~

karlt
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Re: Cycle roof rack failure

Postby karlt » 4 Aug 2017, 8:58am

I've got some of those Halfords cheapies. Don't like 'em, and don't like them even more now! I'm replacing them with Thules. Son #1's FS MTB won't go on the Halfords ones anyway; they can't grip it.

Since getting a car with an instantaneous fuel consumption readout I've become far more reluctant to carry bikes any distance atop the car, which is a pain, because with a Zafira and three kids, where else do you put them? I really, really, don't trust the tailgate carriers. Must get a towbar fitted!

thirdcrank
Posts: 30877
Joined: 9 Jan 2007, 2:44pm

Re: Cycle roof rack failure

Postby thirdcrank » 4 Aug 2017, 10:19am

There are all manner of problems which only occur at motorway speeds eg the Con and Use Regs were only extended to include tyre tread depth in 1967 when aquaplaning had been identified as the cause of some spectacular crashes.

My original cycle carriers were from the "Paddy Hopkirk" range. For younger readers (and older readers with a poor memory) he had been a rally driver and marketed go-faster accessories like "rally" accelerator pedals for your standard Mini. :lol: I had four fitted on the roof of my Renault 4 (disparagingly known in the family as the "brown chugger" to differentiate it from its predecessor, the "white chugger.") I eventually found that the set-up would go on the front part of the roof of my Land Rover. All it needed on a long, trundling trip was an occasional check to ensure everything was still tight. Several years ago I was steaming up the A1(M) in our Rav 4 and we thought everything looked OK when seen through the glass sunshine roof when a chap in an overtaking van was waving and pointing frantically at the bikes. Although things were still all on board, one of the clamps on one of the carriers had bent almost completely straight, where there had previously been two right angles. The bike it had been holding wouldn't have stayed up there much longer.

That was what first had me looking at videos on line and plumping for Thule.

More recently, I was investigating the possibility of towball-mounted carriers and I found even more horror vids of cheapo makes.