Failure of Thule J-bars^

Places, technique, kayaks, safety, the sea...
juliasixtyfive
Posts: 42
Joined: Fri May 11, 2007 8:53 am

Failure of Thule J-bars^

Post by juliasixtyfive » Thu Sep 01, 2011 10:22 pm

In high winds heading west at the Rest and be Thankful on Sunday one of my Thule j-bars failed with the plastic block at the bottom of the J shearing off.
Luckily I was able to pull over into a lay-by almost immediately and push the kayak back onto the roof rack with one hand while flagging down a very helpful motorist travelling in the opposite direction with the other. He, along with his wife, helped me get the boat and j-bars off the roof then re-secure my kayak straight onto now padded roof bars, cockpit down, double strapped and tied down at the front.

(Realising that the wind was gusting strongly I'd actually pulled over a few minutes before this happened to double check that the boat was securely tied down and the roof rack was solid - it had all appeared to be fine. I was driving at 40mph when the plastic cracked.)

See photos of the damage here https://picasaweb.google.com/1127617454 ... directlink and also a photo showing the other j-bar for comparison.

Clearly this incident could have had a far worse outcome, nobody was hurt, my kayak was not damaged, nor was my car or roof rack.

However, I am wondering first if anyone else had had this problem with the Thule j-bars, and second, given that I have to rethink my carrying system am not sure which j- or v-bars to trust,,, which have the sturdiest fittings, and are the most reliable?

Thanks
Julia

User avatar
Curly67
Posts: 78
Joined: Mon Aug 29, 2011 2:11 pm
Location: Chorley, Lancashire

Re: Failure of Thule J-bars

Post by Curly67 » Thu Sep 01, 2011 10:30 pm

I use Ecla V bar splits on the top of my Transporter with plenty of padding. They adjust to the width of any Kayak. I`ve had no problems Transporting the Taran!
Rockpool Taran

P&H Delphin 150

User avatar
immunogirl
Posts: 271
Joined: Tue May 17, 2011 10:58 pm

Re: Failure of Thule J-bars

Post by immunogirl » Thu Sep 01, 2011 11:34 pm

How are you tying down? Tether to the roof rack as well as the J cradles when you tie down - so all of that force isn't working on the plastic connectors of the J cradles exclusively. Are you tethering the front & back of the kayak as well?

juliasixtyfive
Posts: 42
Joined: Fri May 11, 2007 8:53 am

Re: Failure of Thule J-bars

Post by juliasixtyfive » Thu Sep 01, 2011 11:37 pm

Straps were tied down to the roof bar and the car's roof rail. Didn't have the front or back tied down.

User avatar
immunogirl
Posts: 271
Joined: Tue May 17, 2011 10:58 pm

Re: Failure of Thule J-bars

Post by immunogirl » Fri Sep 02, 2011 1:44 am

Jbars, of course, shouldn't do that or break like that... But a kayak sitting upright on your roof is a huge wind resistant sail and it sounds like you were out on a really windy day... Try contacting thule and seeing if they'll replace it or give you new parts.

I've seen a couple too many rack failures, so I always tether front & back, no matter how far I'm driving or not (I know a lot of people who don't tether unless they're going long distances). I don't have the thule J bars, but I have the yakima version. I have heard that a lot of people have issues with the J bars breaking if they wrap around the loop at the top of the j bars, then over the kayak, without tethering from the loop at the top down to the roof rack bars. I've been using my yakima J bars and yakima mako saddles for about 7 years now...They've gone on multiple 18 hour drives at 80 mph+ highway speeds, and I've not had a failure. Tethering front & back helps a lot.

User avatar
zec01
Posts: 225
Joined: Sat May 12, 2007 7:17 pm
Location: Southend on Sea Essex

Re: Failure of Thule J-bars

Post by zec01 » Fri Sep 02, 2011 9:24 am

I have the KariTek J Bars on the easyload rack, they are well built and make other J bars look anorexic in comparison,
saying that I would always tie my kayak down front and back if I was going to be travelling on a fast road!

You should email the company the photos!
If it hurts, you are still alive!

juliasixtyfive
Posts: 42
Joined: Fri May 11, 2007 8:53 am

Re: Failure of Thule J-bars

Post by juliasixtyfive » Fri Sep 02, 2011 9:41 am

Yep, an email has gone off to Thule with the link to the photos and an explanation of what happened, inviting their comment. I will post any reply I get...
As to tie downs - there's been lots of discussion of this before, an in particular Douglas' story posted here http://www.ukriversguidebook.co.uk/foru ... ns#p459006 stayed in my head...
I am reverting to Malone v-bars for now, I also have Malone J-bars but they don't fit my low volume Rockpool Isel too well, and I'm a little concerned about the Malone bars too as I've heard stories of the plastic bars cracking. On the plus side the brackets seem very sturdy. I now have some of these http://www.ajkayakequipment.com on order to try.

User avatar
MikeB
Posts: 7958
Joined: Tue Apr 29, 2003 9:44 pm
Location: Scotland

Re: Failure of Thule J-bars

Post by MikeB » Fri Sep 02, 2011 10:39 am

Terrifying - is this rack system held down by a plastic bracket?

Interestingly, both KCS and KariTek use a substantial metal plate. Mike.

User avatar
Strad
Posts: 1867
Joined: Fri Nov 02, 2007 10:27 am
Location: Bristol(ish)
Contact:

Re: Failure of Thule J-bars

Post by Strad » Fri Sep 02, 2011 10:55 am

every upright or j bar I've owned has been welded to a metal bracket - do Thule really use a plastic connector - that dints my view of view thule usually being the most robust products.
Old School?? I miss my AQII..
Graham Stradling

juliasixtyfive
Posts: 42
Joined: Fri May 11, 2007 8:53 am

Re: Failure of Thule J-bars

Post by juliasixtyfive » Fri Sep 02, 2011 11:04 am

Yep, it was a bit terrifying... I needed a stiff drink when I arrived back (more than one would have been better, but the bottle was sadly already almost empty).
There's rubber across the bottom of the J which the boat rests on, and then plastic on the underside of that which is bolted to the metal J. The plastic piece sits on the top roof bar and the main securing bolts go through the metal J, then through the plastic block, then there's a metal piece that creates the underside of the clamp (hope I'm explaining that clearly enough, I think the photo of the undamaged bar shows the set up reasonably well). The bolts ended up pretty bent. The rubber piece and some of the plastic blew well away, but again one of the photos shows that the plastic that sheared away is actually quite a thick piece. I had really liked the Thule bars because they cradled my low volume boat much more snugly than others I had tried (partly because it's possible to slide the pads on the upright part of the J to give a good fit). But the bolts are definitely less substantial than those on Malone bars and the Karitek ones and I'm definitely not looking to buy another set now.
Last edited by juliasixtyfive on Fri Sep 02, 2011 11:06 am, edited 1 time in total.

User avatar
Jim
Posts: 13497
Joined: Sun Apr 21, 2002 2:14 pm
Location: Dumbarton

Re: Failure of Thule J-bars

Post by Jim » Fri Sep 02, 2011 11:06 am

It is important to understand the mechanics of how you tie a boat on.
Douglas' current roof rack system does seem to be rock solid so he doesn't use end tie downs any more based on the experience of the previous failure, but I think he would admit that perhaps he hadn't arranged the tie downs in the best way on that occasion. although collapse of a rack will allow slack into any system.

To me the most important tie down is at the bow, the main purpose is to stop the bow lifting due to the airflow when driving at speed, the secondary purpose is to restrain the boat from shooting forwards under emergency braking. The first criterion can be met quite easily, for the second criterion the attachment on the boat needs to be further forward than the attachment on the car, then as long as the straps stay in place the boat cannot move forward. If the straps break the boat could actually move forward and down on an arc formed by considering the tie down rope as the radius.
Obviously in high winds, the lift forces and lateral forces can vary in direction and effect depending on the wind direction relative to the direction of travel - if you drive at 70 mph into a 20mph head wind the boat is in 90mph airflow trying to lift the bow, if the wind is not directly ahead it will be trying to twist and tear the boat off the rack in other directions.

The stern tie down is less important but usually easier to get right, in this case the attachment to the boat should be behind the attachment at the car to stop the boat moving backwards (some hull shapes cause you to put both straps over the narrow end of a wedge shape and over time that can force the kayak back).

Only when front and rear tie downs are properly arranged in addition to roof rack straps can you be certain that the boat cannot move forwards or backwards, or side to side. Also you will spread the loads out more so reduce the chance of breaking any component in the system.

For short journeys I often just use the roof rack straps, for short journeys with motorway I will often just add the bow tie down, for longer journeys and in windy conditions I add both.

Also important when adding tie downs is to get the tension right - you don't want slack, but you also dont want to bend your boat. you need just enough tension to start to compress the padding on the roof rack/cradle (bearing in mind you have already compressed it some with the rack straps), sometimes this is actually an indication that you just put on a little too much.

Regarding cradles, I finally upgraded to a set of Karitek J bars this week, only to find my boat wouldn't sit properly on them at all. I arranged to meet Geoff last night and he explained that the bend at the base of the J has been tightened up to fit a wider range of boats better, but I was unlucky to have one it didn't fit so well. We found that the sit on top version does suit my hull (a tip for Taran owners!) although with the restraints of my roof rack positioning (engages in holes in the door frame/roof girder so cannot be altered) it has taken a bit of work to find the position where the boat does sit with the best contact. I would say if you have trouble finding a cradle to suit your boat, find time to visit Karitek and see if they have a version which works for you - unavoidable elements such as the spacing of the racks can mean that what works for one person may not work for another with an identical boat!

The whole of the Karitek J bars are flexible so that they can be pulled up as snug as possible around the hull - I have no idea what the long term fatigue issues with them will be, but there are a lot in use and have been for a long time so I guess they must be OK. I have to admit I am considering for windy weather backing them up with my old uprights, I'll see how they go for now. As regards the fixing system - it's not a flimsy bit of moulded plastic like your photos show, the whole cradle is made from a single piece of 10 or 12mm thick polythene (I think) and the bolts pass straight through this to the clamp plate - there are no intermediate bits, the clamping arrangement is virtually as strong as the rest of the cradle. I have no practical experience of whether they will be better than the Thule ones but that whole clamp arrangement has alarm bells ringing for me. I agree with Immunogirl, contact Thule customer support and see what they say. Aim to get some money back (towards the new cradle), if they insist on replacing it you can always liquidate it on ebay later if you still have no confidence in the bars.

(Mike and Strad got in before me. Mike - Karitek J's don't have a metal plate on top, unless the J itself is a plastic covered plate, but I got the impression it's solid polythene, much stronger than that moulded bracket though, and the lower part is a thick alloy plate)

Jim

User avatar
MikeB
Posts: 7958
Joined: Tue Apr 29, 2003 9:44 pm
Location: Scotland

Re: Failure of Thule J-bars

Post by MikeB » Fri Sep 02, 2011 11:25 am

Jim wrote:
(Mike and Strad got in before me. Mike - Karitek J's don't have a metal plate on top, unless the J itself is a plastic covered plate, but I got the impression it's solid polythene, much stronger than that moulded bracket though, and the lower part is a thick alloy plate)

Jim
Indeed so - K/tek cradles are held down using countersunk machine screws, through the bottom of the cradle. There's no internal metal re-inforcement that I know of - it's just the polyprop material itself. It then uses a thick metal plate to secure to cross bars. I cant recall how it attaches to the Easy Loader system. I can't recall if the plate is threaded, or just a plate.

KCS is slightly different and uses a captive nut insert in the cradle itself, which then receives the bolts to attach, these passing through a substantial metal plate. If anyone can tell me the brand name / generic term for the insert that's used, that would be helpful incidentally. As I understand it, it starts out as two halves which are joined to form the captive nut.

Either way, these cradles are very strong. I've had the weight of an Aleut II flatten my KCS cradles to the point where they were almost straight! They came back up afterwards and are still fine some 6 years afterwards. KCS ones do seem less flexible than K/tek ones it has to be said.

Mike.

juliasixtyfive
Posts: 42
Joined: Fri May 11, 2007 8:53 am

Re: Failure of Thule J-bars

Post by juliasixtyfive » Fri Sep 02, 2011 11:39 am

Thanks guys.
I'll experiment with the foam cradles, and have a chat with Jeff about bars that are a good fit for the Isel. Haven't tried my boat in KCS j-bars but I agree that they seem more rigid than Karitek's... are the KCS bars still available? I think I'll also still use the Malone j-bars when I want to be able to load the boat on my own as I'm a bit of a weakling and find the easy loading bars that work with them pretty good and if I'm heading out for a solo paddle it's unlikely to be an especially windy day.
I'm also rethinking a bow tie-down. I certainly used one for the remainder of the journey on Sunday, and I'm thinking about trying this http://www.ukriversguidebook.co.uk/foru ... ar#p257332 in future, after reading lots of old but very relevant posts since this happened. Lastly, I will avoid the Rest and be Thankful next time I'm driving from Ballachulish to Dunoon on a gusty day! I suspect I'd have had less of a problem had I gone the Inveraray route.

User avatar
Jim
Posts: 13497
Joined: Sun Apr 21, 2002 2:14 pm
Location: Dumbarton

Re: Failure of Thule J-bars

Post by Jim » Fri Sep 02, 2011 11:50 am

I would assume for the easy loader, because it has a track slot in the top, that the plate is tapped, it may even be shaped with a shoulder to centralise in the slot (called a T-nut in machining circles but I have seen the term used for something different). Getting to nuts inside the track would be very fiddly.

There are all kinds of nutserts and rivnuts out there, I have no idea what the correct names of any are, A2A4 have some but I don't recall seeing any 2-part ones.

User avatar
MikeB
Posts: 7958
Joined: Tue Apr 29, 2003 9:44 pm
Location: Scotland

Re: Failure of Thule J-bars

Post by MikeB » Fri Sep 02, 2011 11:55 am

juliasixtyfive wrote: are the KCS bars still available?.
I suggest dropping them a line expressing interest if you want some. I've been in touch with Kyle Thomson, the late Mike T's son, and he told me he would consider getting a batch made if there was sufficient pre-order. He has V's available from stock.

Details on the SPS / KCS website, see the Alamanac / Retailers.

User avatar
MikeB
Posts: 7958
Joined: Tue Apr 29, 2003 9:44 pm
Location: Scotland

Re: Failure of Thule J-bars

Post by MikeB » Fri Sep 02, 2011 12:00 pm

Jim wrote: There are all kinds of nutserts and rivnuts out there, I have no idea what the correct names of any are, A2A4 have some but I don't recall seeing any 2-part ones.
Thinking about it a bit more, it must be a "one part" fitting - I guess the top and bottom is splayed somehow when fitted, to locate it - they certainly have serrations which bite into the material to hold them. Or, until the bolt used corrodes solid and they strip - - -

User avatar
Jim
Posts: 13497
Joined: Sun Apr 21, 2002 2:14 pm
Location: Dumbarton

Re: Failure of Thule J-bars

Post by Jim » Fri Sep 02, 2011 12:19 pm

MikeB wrote:
Jim wrote: There are all kinds of nutserts and rivnuts out there, I have no idea what the correct names of any are, A2A4 have some but I don't recall seeing any 2-part ones.
Thinking about it a bit more, it must be a "one part" fitting - I guess the top and bottom is splayed somehow when fitted, to locate it - they certainly have serrations which bite into the material to hold them. Or, until the bolt used corrodes solid and they strip - - -
Hmm, A2A4 catalogue seems to have shrunk slightly - I'm sure there were some captive nuts on not so long ago!

Try these - the 'other' type of T nut I was talking about :
http://www.orbitalfasteners.co.uk/produ ... fAodVHWyzw

Rather than these which are used to attaching things to machine tables etc:
http://www.wdsltd.co.uk/products/Standa ... etric-548/

User avatar
zec01
Posts: 225
Joined: Sat May 12, 2007 7:17 pm
Location: Southend on Sea Essex

Re: Failure of Thule J-bars

Post by zec01 » Fri Sep 02, 2011 12:30 pm

Yep the KariTek has a threaded square piece of metal that slides into the slotted roofrack, the J Bars are very chunky but I stll strap down to the roofrack!
If it hurts, you are still alive!

juliasixtyfive
Posts: 42
Joined: Fri May 11, 2007 8:53 am

Re: Failure of Thule J-bars

Post by juliasixtyfive » Fri Sep 02, 2011 12:39 pm

I've posted some better photos of the undamaged Thule j-bar's fittings here: https://picasaweb.google.com/1127617454 ... directlink also if you're interested in the Malone Easy Loader's top fitting that slots into the side of the their j-bars, some pictures are here: https://picasaweb.google.com/1127617454 ... directlink

User avatar
MikeB
Posts: 7958
Joined: Tue Apr 29, 2003 9:44 pm
Location: Scotland

Re: Failure of Thule J-bars

Post by MikeB » Fri Sep 02, 2011 5:45 pm

Jim wrote: Try these - the 'other' type of T nut I was talking about :
http://www.orbitalfasteners.co.uk/produ ... fAodVHWyzw
Hmm - no - whatever is in there is much more sophisticated than that. Having put a hacksaw through the rusted in studs, even a 5lb hammer with a drift isn't shifting the insert. If it was those T nuts it would just pop out. Mike.

User avatar
Jim
Posts: 13497
Joined: Sun Apr 21, 2002 2:14 pm
Location: Dumbarton

Re: Failure of Thule J-bars

Post by Jim » Fri Sep 02, 2011 6:31 pm

Anything off this site look similar?
http://www.insertsdirect.com/

Is it possible the plastic is moulded around the insert or do they appear to be retrofitted?

User avatar
MikeB
Posts: 7958
Joined: Tue Apr 29, 2003 9:44 pm
Location: Scotland

Re: Failure of Thule J-bars

Post by MikeB » Fri Sep 02, 2011 7:48 pm

Ah - now that's interesting - I would imagine these things were put into the cradle after forming - getting it into the material in some way wouild be a challenge for a small volumn producer I would imagine, and Mike T always went for simple solutions.

it could well be that they used the "Multifit" http://www.insertsdirect.com/productCat ... 4359953b4e (it certainly has a "head" or flange of some sort - and given it won't pop out, I suspect it's got a retaining flange at the other side too - so put in with a tool of some sort). I am questionning whether it's brass - when it was all shiny and new, it looked like steel - and the ones I was able to free off certainly seem to be steel - and given the ease with which the steel stud corroded into place - - with no evidecne of dis-similar metal corrossion that I can see.

I'm going to have to find someone with a pillar drill to get the old one out I suspect. The annoying thing of course is that, apart from the rust, the studs were actually ok once I finally got the nuts off. My justification to myself is that 15 year old rusty studs are not the ideal thing to be holding a kayak rack on with! Had I Coppaslipped the blasted things in the first place, then all would have been well - hey ho.

Mike.

User avatar
gasserra
Posts: 37
Joined: Thu Jan 21, 2010 11:43 pm
Location: Northern Virginia,USA

Re: Failure of Thule J-bars

Post by gasserra » Fri Sep 02, 2011 8:12 pm

Thanks for posting this; it's an important topic.

Reading your descriptions--both your original post and your follow-up details--it's still not obvious to me what the mechanism of failure here was.

The greatest vulnerability of these rack systems when hauling long sea boats is the lift generated on the front overhang. For a sea boat, that can be a 5 or 6 foot overhang, so the upward torque applied to the front rack can be very severe, and even good rack systems can't really sustain this force well. A snug front tie down provides substantial protection against this. You didn't use a front tie down, and you didn't mention which J-bar failed--I initially assumed it was the front, and that would be the case if the problem was lift as I discussed.

However, then you mentioned that you strapped the boat to the roof bar system, not the J-bar, and you don't describe the roof bar as having failed; i.e., I infer that the rack bar didn't fail. So it doesn't seem like lift was the key problem here. Your pictures of the damage to the plastic base and bolts of the J-bar suggest that lateral twisting (yaw) cracked the base of the J bar, and that once that internal support was removed, the upright parts of the J-bar would have been able to twist even more, allowing the boat to slip. If this is true, then a front tie down would still have been useful, but unless you used an inverted "V" tie down--one end on each side of the car with the apex at the kayak bow, even a front tie down would still have allowed a bit of yaw and might not have prevented the failure.

My guess is that when you hear back from Thule, they'll say that if you didn't have fore and aft tie downs in addition to the rack straps, the system was vulnerable. Their J bar instructions do emphasize the bow & stern tie downs.

juliasixtyfive
Posts: 42
Joined: Fri May 11, 2007 8:53 am

Re: Failure of Thule J-bars

Post by juliasixtyfive » Fri Sep 02, 2011 8:53 pm

It was the front j-bar that failed.

User avatar
immunogirl
Posts: 271
Joined: Tue May 17, 2011 10:58 pm

Re: Failure of Thule J-bars

Post by immunogirl » Fri Sep 02, 2011 10:21 pm

juliasixtyfive wrote:Yep, an email has gone off to Thule with the link to the photos and an explanation of what happened, inviting their comment. I will post any reply I get...
As to tie downs - there's been lots of discussion of this before, an in particular Douglas' story posted here http://www.ukriversguidebook.co.uk/foru ... ns#p459006 stayed in my head...
I am reverting to Malone v-bars for now, I also have Malone J-bars but they don't fit my low volume Rockpool Isel too well, and I'm a little concerned about the Malone bars too as I've heard stories of the plastic bars cracking. On the plus side the brackets seem very sturdy. I now have some of these http://www.ajkayakequipment.com on order to try.
Having read Douglas's story - that all really depends on how you are tying down & what anchor points are you using. How were the straps arranged on the J bar that failed? If the kayak was tethered to the J bar and not the rack, then the kayak can swing around... I had some friend come pick me up once to start a 14 hour drive with our boats and he had his bow tethered with an S hook to the plastic grill in front of his VW golf. If you anchor your front tethers in a weak spot or at a weak angle, they're not going to be helpful. Douglas had his front rope snap, but not his back rope snap.

I don't use webbing, because that tends to wear with friction. I buy high strength rope. I don't use pulleys or whatever, I tie prusik knots (friction knots that climbers use)... And I dress the knot, tie off the ends. I do use those hood loops. And I keep an eye on my boats when they're on my roof. And, I make sure that I'm tying down all the boats myself (I've done it so much that other people slow me down trying to be helpful).

I prefer the yakima mako saddles, because you can adjust them to the width of the boat & because in combination with the boat loader bar, I can cartop my boats myself (my suburu is high for a short person). I have a couple of sets of j cradles that I pop on the roof if i need to carry a 3rd or 4th kayak to the roof rack, but I'm not tall enough to car top a boat with them. When I do use a J rack, they're positioned next to my towers, and the strap gets tethered to the bar on both sides of the tower, so the strap can't slide along the bar...


The 2 times I was present where roof racks failed was cars being driven highway speeds with kayaks on the roof & not tethered in a rain or snow storm... The roof racks were those after market thule or yakima ones that mount in the door frame and get tightened for a certain spot on the car. The upward lift of the kayaks was enough to pry up on the thule/yakima towers let a little bit of moisture (snow in one case, rain in the other) get under the pad... and then the entire roof racks slid backwards on the car roof - once the roof racks slide backwards, they're in a narrower spot of the car then they've been tightened for, so you've just got a floating roof rack being held on your car by the little metal clips that go in the door frame. It wasn't good.

Fulmar
Posts: 14
Joined: Wed Aug 24, 2011 11:12 am
Location: Warton Lancs

Re: Failure of Thule J-bars

Post by Fulmar » Sat Sep 03, 2011 11:22 am

We purchased a set of Kari-Tec J bars to carry our Scorpio Lv last year.3 months ago my wife and i dropped the wet/slippery kayak on to the bonnet of the car trying to lift it over the bottom end of the J . The problem with J bars is that the kayak has to be turned sideways when lifting it on to the J.The kayaks are also prone to movement even when strapped on correctly ,due to the springiness of the J bars.I have since sold them and now use PROrack available from Roofbox Company (roofbox.co.uk) for both my kayaks.The kayaks sit upright on fully adjustable V's.They can be loaded sideways or even from the back of the car.When strapped on, the kayaks do not move at all even at higher motorway speeds.If you only carry a maximum of 2 kayaks, the PROracks are the safest way of loading and transporting kayaks.
David
Tiderace Xplore S

User avatar
MikeB
Posts: 7958
Joined: Tue Apr 29, 2003 9:44 pm
Location: Scotland

Re: Failure of Thule J-bars

Post by MikeB » Sat Sep 03, 2011 11:50 am

Those observations about J's are certainly worth considering, especially the need to rotate the boat 90 degrees. I like the slight flexibility in the J set up though. It would seem to provide a degree of "shock absorption". Mind you, I once had two singles and a double on the rack. Watching that lot move around at speed, with a side wind, was enough to make me add bow and stern ties!

The "V" set up it great as long as the boat sits level - for those cars with a sloping roof, it sits bow high and exposes all the flatish hull surface to those motorway speed winds. Definitly a case where it's worth using ties front and stern. Especially so with a small(ish) car where the bars might be fairly close together.

A lot of 2/3 door cars don't seem to have much in the way of attachment for the rear bars - in some cases, it's a flimsy clamp in the rear window recess. If that's the case, then beware!

There is much to be said for choosing your paddle-wagon based on what sort of roof rack attachment points it has! I like estates, and put great faith in factory fitted roof rails. Any saloon with a dedicated rack attachement point has got to be good too. BM's and Vauxhall come to mind iirc.

Mike.

tannys
Posts: 95
Joined: Mon Jun 07, 2010 11:16 pm

Re: Failure of Thule J-bars^

Post by tannys » Sat Sep 03, 2011 7:51 pm

I had a very similar thing happen in high winds in may (rather bloody scary it was) not with thule J's but same style of double bars and metal bracket, the company sent new J bars and I now always carry a spare set of cradles

(Admin Edit 5/9/2011 - to add link the the post relating to this - here. )
"Paddle solo, sleep tandem"

juliasixtyfive
Posts: 42
Joined: Fri May 11, 2007 8:53 am

Re: Failure of Thule J-bars^

Post by juliasixtyfive » Sat Sep 03, 2011 9:01 pm

No reply from Thule yet... but after that experience I do not want to use replacement Thule j-bars in any case.
Malone v-bars with roof bars a bit wider than 'normal' and with straps secured to roof rails worked fine today.

User avatar
MikeB
Posts: 7958
Joined: Tue Apr 29, 2003 9:44 pm
Location: Scotland

Re: Failure of Thule J-bars

Post by MikeB » Mon Sep 05, 2011 1:06 pm

gasserra wrote: However, then you mentioned that you strapped the boat to the roof bar system, not the J-bar, and you don't describe the roof bar as having failed; i.e., I infer that the rack bar didn't fail. So it doesn't seem like lift was the key problem here. Your pictures of the damage to the plastic base and bolts of the J-bar suggest that lateral twisting (yaw) cracked the base of the J bar, and that once that internal support was removed, the upright parts of the J-bar would have been able to twist even more, allowing the boat to slip. If this is true, then a front tie down would still have been useful, but unless you used an inverted "V" tie down--one end on each side of the car with the apex at the kayak bow, even a front tie down would still have allowed a bit of yaw and might not have prevented the failure.

My guess is that when you hear back from Thule, they'll say that if you didn't have fore and aft tie downs in addition to the rack straps, the system was vulnerable. Their J bar instructions do emphasize the bow & stern tie downs.
If it's a Thule Hull-a-Port, then it has to be strapped to the rack. A pal uses one and I was looking at it yesterday. The picture on the roofracks.co.uk site even shows this.

Image

There's nothing to attach the straps to at the bottom of the rack, unlike the Malone, KCS and KariTek cradles where the straps pass though slots at the top and the bottom. The strap has to pass round the roof bar to be tensioned. I've not found a ref to using bow & stern ties but given the picture doesn't show them - - -

I'm no engineer, but even my rudimentary understanding of this stuff is telling me that there must be a severe lateral leverage against the bolts and the plastic bracket holding the whole thing together once a boat is strapped on with the strap round the top curve of the bar, as per the picture above. (Which is how my pal tied his boat down - the ends / prongs of the cradle don't allow any attachment at that point).

The bolts aren't especially chunky either, nor is the attachment plate. In fact, I noticed that my friend's rear cradle had moved sideways after one journey - resetting it was easy with the thumb nuts of course, but it didn't seem a very substantial set up. (Just my uneducated, personal opinion of course.)

They're also quite expensive - - -

I like Thule bars and the fitting kits - not too sure I like the cradles though. Mike.

Post Reply