Torque value for plastic cowling hex bolts
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madmike2
Shtirrenuppenmeister
06FJRider
Active member
I should have added the reason for looking for this answer..
[Note: Serious tone mode turned on]
As a result of a "just snuggin' it up tight" (by yours truly) application of hand-applied torque, the threaded spring clip crushed the retaining tab of one of the plastic panels... The fragility and the ease of destruction of a not-so-inexpensive part has, of course, led me to this question rather than a concern over a loss of the fastener (being a firm believer in threadlocker). Inspection of the side cowling (removed to recover broken pieces) revealed that there are a number of places where the same design could repeat the failure in the future.
And yes, I do own a torque wrench that is accurate in inch-pounds - useful for many things (including mounting scopes to help ensure accuracy as best possible...) In this case, I am seeking to quantify a recommendation in terms that are easily repeatable /reproducible /measurable, to help prevent future repairs /replacement for myself and others. Creating this definition also has a side benefit that it can become a torque recommendation to the grease monkey at a shop working on your bike - to help prevent issues there (it is pretty easy to use a T-wrench and end up overtighting these panels - yes, the shop experienced that and had to buy me a panel at a previous time).
For now, my recommendation (based on interpretation of the general torque recommendation table in the FSM) is to use 18 - 24 inch-pounds when fastening the plastic panels with the M4 screws (if no other torque is given by the FSM). Is there any other recommendation that anyone has, and that meets the needs to be repeatable and measurable?
Thanks!
[serious tone mode turned off - please continue bashing /joking around...
]
[Note: Serious tone mode turned on]
As a result of a "just snuggin' it up tight" (by yours truly) application of hand-applied torque, the threaded spring clip crushed the retaining tab of one of the plastic panels... The fragility and the ease of destruction of a not-so-inexpensive part has, of course, led me to this question rather than a concern over a loss of the fastener (being a firm believer in threadlocker). Inspection of the side cowling (removed to recover broken pieces) revealed that there are a number of places where the same design could repeat the failure in the future.
And yes, I do own a torque wrench that is accurate in inch-pounds - useful for many things (including mounting scopes to help ensure accuracy as best possible...) In this case, I am seeking to quantify a recommendation in terms that are easily repeatable /reproducible /measurable, to help prevent future repairs /replacement for myself and others. Creating this definition also has a side benefit that it can become a torque recommendation to the grease monkey at a shop working on your bike - to help prevent issues there (it is pretty easy to use a T-wrench and end up overtighting these panels - yes, the shop experienced that and had to buy me a panel at a previous time).
For now, my recommendation (based on interpretation of the general torque recommendation table in the FSM) is to use 18 - 24 inch-pounds when fastening the plastic panels with the M4 screws (if no other torque is given by the FSM). Is there any other recommendation that anyone has, and that meets the needs to be repeatable and measurable?
Thanks!
[serious tone mode turned off - please continue bashing /joking around...
]I can appreciate your concern. However, you're half way there in learning the proper feel to the task. You already know what over tight feels like, now tighten it less than that. Yes, I agree that it's easy to over do it with a T handle. The two finger method works well for most folks.
I too have an in/lb torque wrench, but not one that goes that low. I know they do exist, but it's rare for any torque wrench to be particuarly accurate at the low end of the scale, (or the high end). And inch pounds is really all about feel unless you're doing cam shaft caps, or similar.
road runner
Well-known member
I think if you have to ask this then put the wrench down and step away from the bike. :blink:
This is something you do by feel on these little fasteners, and that comes from experience. The way to get that is to do it wrong a few times , then you will know how to do it. So if you must do it yourself and don't really know what you are doing, be prepared to hit some bumps in the road,so to speak.
This is something you do by feel on these little fasteners, and that comes from experience. The way to get that is to do it wrong a few times , then you will know how to do it. So if you must do it yourself and don't really know what you are doing, be prepared to hit some bumps in the road,so to speak.
wfooshee
O, Woe is me!!
I would really expect the spring clip to strip before the plastic tabs break or get crushed. I'm thinking something else has happened to stress the tab. As the bolts are removed the fairing should not be allowed to hang from the upper three bolts. That will break those tabs. The upper bolts should be the first removed. Also, a bike drop might bump that area harder than it's designed to take.
And there is absolutely no reason to use Loctite on the fairing bolts. There's not enough thread surface on the spring clip for it to adhere to anyway, less than one turn of the bolt thread is in contact. The bolts that go to other plastic panels (the ones with spring clips and tabs) don't carry any of the plastic's weight, they simply close the seam. The fairing's weight is carried by the bolts into the frame. There's nothing going to fall off or loosen up as long as those bolts are hand tight. I give a little push on the hex key after it snugs up. Not even a quarter turn, maybe not even an eighth.
If you've ever assembled the fairing off the bike, you see that it's a surprisingly rigid structure. The weight of that structure is carried by the headlight assembly attachments and the side bolts on the lower panels. The rest, like I said, just closes the seams and has no stress. When the hex key in your hand stops, it's tight enough. That's all there is to it.
And there is absolutely no reason to use Loctite on the fairing bolts. There's not enough thread surface on the spring clip for it to adhere to anyway, less than one turn of the bolt thread is in contact. The bolts that go to other plastic panels (the ones with spring clips and tabs) don't carry any of the plastic's weight, they simply close the seam. The fairing's weight is carried by the bolts into the frame. There's nothing going to fall off or loosen up as long as those bolts are hand tight. I give a little push on the hex key after it snugs up. Not even a quarter turn, maybe not even an eighth.
If you've ever assembled the fairing off the bike, you see that it's a surprisingly rigid structure. The weight of that structure is carried by the headlight assembly attachments and the side bolts on the lower panels. The rest, like I said, just closes the seams and has no stress. When the hex key in your hand stops, it's tight enough. That's all there is to it.
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06FJRider
Active member
I'll close this thread with these answers /comments to the open questions.
Yes, the spring clip was able to crush the mounting tab - I had to pry open the clip to remove the pieces. The bike has not been dropped or hit by something, so I do not expect that to be a reason. Was it a bit of over-zealous tightening? Most probably.. Had I taken this part off before without any issues found? Yes; I probably was more careful when I mounted it and applied lower torque, as compared to this last time.
I cannot honestly remember "torquing down" on it - like several have mentioned I too normally follow a process of bringing it to snugness by hand and then apply a 1/8, or less, more turn to finish. To make my life simpler, I will use my torque wrench since I have it anyways and it lets me remove my own "ham-fistness" out of the equation. For those interested in good accuracy inch-pound torque wrenches, I suggest this one (similar to what I have and rated for accuracy in the 10 to 65 inch-pound range); you can find these kind of wrenches in many purveyors:
https://www.midwayusa.com/viewproduct/?productnumber=718023
Regards to all! Luis
Yes, the spring clip was able to crush the mounting tab - I had to pry open the clip to remove the pieces. The bike has not been dropped or hit by something, so I do not expect that to be a reason. Was it a bit of over-zealous tightening? Most probably.. Had I taken this part off before without any issues found? Yes; I probably was more careful when I mounted it and applied lower torque, as compared to this last time.
I cannot honestly remember "torquing down" on it - like several have mentioned I too normally follow a process of bringing it to snugness by hand and then apply a 1/8, or less, more turn to finish. To make my life simpler, I will use my torque wrench since I have it anyways and it lets me remove my own "ham-fistness" out of the equation. For those interested in good accuracy inch-pound torque wrenches, I suggest this one (similar to what I have and rated for accuracy in the 10 to 65 inch-pound range); you can find these kind of wrenches in many purveyors:
https://www.midwayusa.com/viewproduct/?productnumber=718023
Regards to all! Luis
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06FJRider
Active member
One last post again.. we discussed the torque process /specs but not how the plastic tab was repaired.
I used a kit from the Eastwood Company (see www.eastwood.com and I have no association with) for repairing the broken tab (link below). They call it a "rigid plastic repair kit"; you can get it in black, clear and white colors.
https://www.eastwood.com/catalog/product/vi...ar/category/19/
I found that using this kit to recreate the tab and then using a thin steel plate backing (just a paper thin piece, thin enough to cut easily with tin snips) made for a quite strong repair. I bonded the steel backing with some 5 min epoxy to the tab - the steel backing is large enough to cover the tab and an adjoining area to help distribute any loads /forces.
I may eventually replace the part with a new one but this fix seems to be doing the trick for me.
I used a kit from the Eastwood Company (see www.eastwood.com and I have no association with) for repairing the broken tab (link below). They call it a "rigid plastic repair kit"; you can get it in black, clear and white colors.
https://www.eastwood.com/catalog/product/vi...ar/category/19/
I found that using this kit to recreate the tab and then using a thin steel plate backing (just a paper thin piece, thin enough to cut easily with tin snips) made for a quite strong repair. I bonded the steel backing with some 5 min epoxy to the tab - the steel backing is large enough to cover the tab and an adjoining area to help distribute any loads /forces.
I may eventually replace the part with a new one but this fix seems to be doing the trick for me.
06FJRider
Active member
Along with the Eastwood site (www.eastwood.com) - which for those not familiar with Eastwood, is a very nice site for finding lots of repair /esoteric tools for those working in restoring /maintaining vehicles; here is the site of the plastic repair company whose product was used to do the repair.
The product is called "Plastex" and can be sourced at Eastwood and at their own site:
www.plastex.net
According to their site they now offer the product in blue, red, orange, yellow and green by contacting them directly, along with black, white, clear.
I have no affiliation with either of these places, other than as a satisfied customer.
Cheers all!
The product is called "Plastex" and can be sourced at Eastwood and at their own site:
www.plastex.net
According to their site they now offer the product in blue, red, orange, yellow and green by contacting them directly, along with black, white, clear.
I have no affiliation with either of these places, other than as a satisfied customer.
Cheers all!
double_entendre
Well-known member
There are only three torque settings you need for any fastener on the bike:
White knuckle
Grunt
Break wind
The fairing fasteners are all white knuckle fasteners.
Rancho
White knuckle
Grunt
Break wind
The fairing fasteners are all white knuckle fasteners.
Rancho
I break wind with very little torque... guess that would be my fairing fastener setting. Instead of click, click, click it is puff, puff, puff...
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