Twisted&Broken
Likes Bikes
No issues with thread lining up. There is no female thread on the roof rack, just a hole for the bolt to go through.
Thule roof rack issues
- Thread starter Twisted&Broken
- Start date
MARKL
Eats Squid
I disagree with the statement that Loctite is a "bandaid" but anyhow each to their own.
Do you know if the bolts are being correctly torqued? Essentially the bolt has to be torqued to a point where it creates enough tension to resist the forces trying to undo it, at the same time it shouldn't be torqued to a point where the bolt becomes permanently stretched.
The other thing to check is (I don't know if it is possible) but once you put a load on the roof rack does that effectively squash part of how the rack attaches a bit more; effectively loosening the bolt? Thus explaining why it loosens quicker with bikes on than without bikes.
Cheers and buy some loctite!
Do you know if the bolts are being correctly torqued? Essentially the bolt has to be torqued to a point where it creates enough tension to resist the forces trying to undo it, at the same time it shouldn't be torqued to a point where the bolt becomes permanently stretched.
The other thing to check is (I don't know if it is possible) but once you put a load on the roof rack does that effectively squash part of how the rack attaches a bit more; effectively loosening the bolt? Thus explaining why it loosens quicker with bikes on than without bikes.
Cheers and buy some loctite!
carpetrunner
Likes Dirt
There's loktite and there's loktite
There are a brazillian different types of loktite - I agree you don't want real threadlocker.
The one you want is Loktite 222
This just adds stiction, like a nylock nut, and it feels just like a nylock when you undo it.
All good - Campagnolo specify it for bearing cups, it even lubricates when you tighten to ensure a nice even torque measurement and it has oxidation inhibitors to stop the whole thing rusting up. (sorry sounding like a sales pitch)
Try your local Coventry Fasteners.
I agree that it would be nice to know why they spontaneously undo themselves.
I'd be suspicious of the threads in the roof of the car, are these cut into mild steel?
did they have paint and galvanising treatment over them at one stage and is now gone?
Are the bolts are stainless? Stainless is pretty slippery and Gal (zinc) is a good lubricant against stainless, I don't like stainless into anything without a nylock nut.
I would also be a little worried about the amount of time these have been rattling around when they were lose, it may not obviously damage the threads, but it could just make them a little bigger.
and finally - I saw a road bike swaying in the wind the other day, does your bike move around when it is on the rack?
I can imagine that a constant sway back and forth could loosen bolts in that position.
- carpetrunner
There are a brazillian different types of loktite - I agree you don't want real threadlocker.
The one you want is Loktite 222
This just adds stiction, like a nylock nut, and it feels just like a nylock when you undo it.
All good - Campagnolo specify it for bearing cups, it even lubricates when you tighten to ensure a nice even torque measurement and it has oxidation inhibitors to stop the whole thing rusting up. (sorry sounding like a sales pitch)
Try your local Coventry Fasteners.
I agree that it would be nice to know why they spontaneously undo themselves.
I'd be suspicious of the threads in the roof of the car, are these cut into mild steel?
did they have paint and galvanising treatment over them at one stage and is now gone?
Are the bolts are stainless? Stainless is pretty slippery and Gal (zinc) is a good lubricant against stainless, I don't like stainless into anything without a nylock nut.
I would also be a little worried about the amount of time these have been rattling around when they were lose, it may not obviously damage the threads, but it could just make them a little bigger.
and finally - I saw a road bike swaying in the wind the other day, does your bike move around when it is on the rack?
I can imagine that a constant sway back and forth could loosen bolts in that position.
- carpetrunner
Twisted&Broken
Likes Bikes
Markl. I feel loctite is a bandaid as if it was required to fit the roof racks thule would specify to use it in the fitting instructions. Yes it would possibly stop them coming loose, but won't explain how and why its happening. If you had a leak in your camel back would you fill it with jelly so it doesn't leak water any more?
The current theory from thule is the bolts are over tight and compressing the rubber to much. This sounds weird to me as,they loosen past the point of contact with the rack, but a torque wrench is on its way and will test tomorrow.
The current theory from thule is the bolts are over tight and compressing the rubber to much. This sounds weird to me as,they loosen past the point of contact with the rack, but a torque wrench is on its way and will test tomorrow.
Twisted&Broken
Likes Bikes
Carpetrunner. I used to be a sales rep selling threebond which is another brand of thread lock so know and own all types of locking compound. Again its not finding and fixing the problem in my opinion. I believe the bolts are mild steel as are the "nuts" on the car. No stainless or zinc coat. The bolts don't rattle in the nut and three sets of bolts and no sign of damage to the thread when removed.
Every bike a a roof rack I've seen sways a bit. My brother in law has a subaru outback and has no issue with the same racks. I don't think its excessive movement of the bike.
Every bike a a roof rack I've seen sways a bit. My brother in law has a subaru outback and has no issue with the same racks. I don't think its excessive movement of the bike.
wilddemon
Likes Dirt
Point taken re loctite. Ultimately its thule's responsibility? Have you checked that the bolts end has clearance when done up tight? Are the roof rack bits soft enough that under load in any direction that the tension in the bolt is unloaded and thus susceptible to undoing itself?
Great thread. Who is going to solve the mystery? Lol
Great thread. Who is going to solve the mystery? Lol
MARKL
Eats Squid
Hey Twisted
I tend to agree with the loading/unloading of the bolt as the bike loads and unloads as the car travels. I would tend to think this makes the too tight theory unlikely however if the rubber has been overcompressed in the past/hardened due to age that could make it more succeptible to the loading unloading.
With regards to the analogy of a leak in the camelbak I think the loose bolt is the hole in the camelback, I don't have to know how the hole got there I just know that if I put a bandaid over the hole it won't leak an longer...
I tend to agree with the loading/unloading of the bolt as the bike loads and unloads as the car travels. I would tend to think this makes the too tight theory unlikely however if the rubber has been overcompressed in the past/hardened due to age that could make it more succeptible to the loading unloading.
With regards to the analogy of a leak in the camelbak I think the loose bolt is the hole in the camelback, I don't have to know how the hole got there I just know that if I put a bandaid over the hole it won't leak an longer...
hifiandmtb
Sphincter beanie
The Outback doesn't have bolt-on racks though - it uses longitudinal roof rails that the Thule system clamps onto?
Twisted&Broken
Likes Bikes
Hifi. Well there you go. I know he has thule roof racks and bike racks. Shows how much I've paid attention.
John U
MTB Precision
Even more so when you consider the car has a sunroof.
Twisted&Broken
Likes Bikes
John u. So you think my car is flexing more than all other subaru liberty wagons with genuine or thule roof racks? Thule say they have never heard of this before.
Given the year model I would say you have Thule's rt753 or rt751 that uses a tk3018 fit kit that suits the liberty.
The bolts supplied are mention to be 30mm long (shaft not total)
The pads that support the rack are rubber and it is crucial to tighten on first instalation to 4nm.
If tightened further this will cause the rubber to compress and deform. The problem arises if the bolts have been overtightened, the bolt will pass through the plate which is the "nut" and into the vehicles roof.
What happens now is the plate may have lifted and the racks rubber pad will float.
The only other culprit could be heavy vibration from corrugations on dirt roads loosening the bolts.
Here are the fitting instructions
http://www.thule.com.au/FITTING_GUIDE/3018.pdf
As for a fix, I would see if the pad has compressed and replace the kit if it is.
http://www.thule.com.au/FITTING_GUIDE/3018.pdf
The bolts supplied are mention to be 30mm long (shaft not total)
The pads that support the rack are rubber and it is crucial to tighten on first instalation to 4nm.
If tightened further this will cause the rubber to compress and deform. The problem arises if the bolts have been overtightened, the bolt will pass through the plate which is the "nut" and into the vehicles roof.
What happens now is the plate may have lifted and the racks rubber pad will float.
The only other culprit could be heavy vibration from corrugations on dirt roads loosening the bolts.
Here are the fitting instructions
http://www.thule.com.au/FITTING_GUIDE/3018.pdf
As for a fix, I would see if the pad has compressed and replace the kit if it is.
http://www.thule.com.au/FITTING_GUIDE/3018.pdf
Twisted&Broken
Likes Bikes
Dwain.
Thanks for the info. I already have the fitting instructions and have double and triple checked the fitting along with the Victoria rep for thule and the retail shop I bought them from.
The only thing I can't confirm is the torque setting of 4Nm as no tension wrench was used. I do know the 4Nm isn't much and I haven't excessively tightened the bolts in my opinion. The only time I was concerned about the bolts being excessively tightened was when the Victoria thule rep replaced the bolts one time, but I left him to it as roof racks are his profession and not mine.
When I get the tension wrench today I will check the rubbers for deformities and damage before checking the bolt tension. Hopefully the mystery will be solved.
Thanks again for the info.
Thanks for the info. I already have the fitting instructions and have double and triple checked the fitting along with the Victoria rep for thule and the retail shop I bought them from.
The only thing I can't confirm is the torque setting of 4Nm as no tension wrench was used. I do know the 4Nm isn't much and I haven't excessively tightened the bolts in my opinion. The only time I was concerned about the bolts being excessively tightened was when the Victoria thule rep replaced the bolts one time, but I left him to it as roof racks are his profession and not mine.
When I get the tension wrench today I will check the rubbers for deformities and damage before checking the bolt tension. Hopefully the mystery will be solved.
Thanks again for the info.
John U
MTB Precision
Just saying that if there are flex issues with roof area causing issues with your racks then this would be compounded by the fact you have a sun roof.
Having a look at Dwains post was interesting. I have always got my racks from a roof rack specialist and never a car dealer. I use Thules and have never had any issues (been using them for about 8 years on various cars).
My racks have always been based on the solid looking cross rails as posted by hifiandmtb.
Do you have the option of mounting these types of rails?
Have you been to a roof rack specialist (can't remember if you stated this) eg http://www.roofcarriersystems.com.au/
These dudes have everything and offer quite a bit of stuff second hand. All good in my experience.
John U
MTB Precision
Guess you have done that checking. Ignore my post.
Twisted&Broken
Likes Bikes
Well. i just picked up the tension wrench and checked the bolts. They were way under 4Nm and when I tried tighten them to 4Nm as specified in the fitting instruction they deformed the rubber quite a bit and then cracked the trim on the roof of the car.
Out of interest when I loosened them again I used the supplied Allen key and they felt way tighter then I have ever done them up with the Allen key.
So back to square one and now I have cracked trim panel on my car too.
I just looked a another liberty at we have at my work and the roof of my car is the same, so I don't feel it is an issue with the car but on issue with the roof rack.
Out of interest when I loosened them again I used the supplied Allen key and they felt way tighter then I have ever done them up with the Allen key.
So back to square one and now I have cracked trim panel on my car too.
I just looked a another liberty at we have at my work and the roof of my car is the same, so I don't feel it is an issue with the car but on issue with the roof rack.
Was this using a new fit kit?
As mentioned in my previous post those pads may be damaged.
Did you measure your bracket with the other car?
Can you please measure the roof to the top of the plate/bracket.
Please call me before you do any thing else with your car. You have our shops number.
As mentioned in my previous post those pads may be damaged.
Did you measure your bracket with the other car?
Can you please measure the roof to the top of the plate/bracket.
Please call me before you do any thing else with your car. You have our shops number.
Twisted&Broken
Likes Bikes
Dwain. The rubbers weren't damaged. I pulled them off again tonight and inspected then. The Victoria sales rep is coming to replace them on Tuesday. I've given up until then. If he can't fix it I'll be seeking a full refund. I've double, triple checked, inspected, pulled apart, re installed and I'm just over it.
wombat
Lives in a hole
Really? 4Nm really isn't that much torque at all, if the bolts were way under I'm suprised they stayed tight at all.
Are you sure that your wrench is reading properly?
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