Braiot
Novice Class
Posts: 77
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posted July 12, 2003 04:53 PM
Friggin Forks
I was playing around with my forks today. As I was tightening the fork clamps on the lower triple clamp, one of the bolts broke off.
My Kawi dealership told me that the torque spec for the bottom triple clamp was 15 ft-lbs.
I had the torque set right, so could someone give me some insight as to why the damn bolt broke.
After it broke I took the bolts out of the other clamp that I had just tightened with no problems and both bolts look like they are ready to break as well.
What gives? Is 15 ft-lbs too much? My service manual is on order, so if someone could help me out, I'd appreciate it.
Thanks
  
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frEEk
Administrator
ummm... yeah
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posted July 12, 2003 05:49 PM
yep, 14.5ft-lbs to be exact.
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ZHooligan
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posted July 12, 2003 06:26 PM
It's possible the bolt was over torqued in the past and it chose this operation to break. Also many times the problem with bolts that torque at very low numbers the torque wrench you use can be off some and I have found torque wrenches are not always accurate at the bottom of the range they suposedly measure. I use an inch pound torque wrench for m forks etc.
Just a few thoughts.
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Braiot
Novice Class
Posts: 77
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posted July 12, 2003 06:32 PM
 Edited By: Braiot on 12 Jul 2003 19:36
So why would the bolt twist off? The wrench was set at 15 ft-lbs. I tried to tighten the two side by side bolts a little at a time so there was the same amount of torque on each bolt and it still broke.
ZHooligan, the bike is not even a month old. If the bolts were over tightened, it would have to be from the factory.
Is there a special way to tighten these?
This is seriously pissing me off. The weather is great and I finally have a couple days off and this shit has to happen.
Sorry, had to bitch a little
Thanks
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frEEk
Administrator
ummm... yeah
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posted July 12, 2003 06:36 PM
as zhool said, they could have been overtorqued previously, meaning the damage was already done when u touched the bolts, and they were damaged enough that even the relatively light torque u applied to them was enough to break them. as he also pointed out, ur wrench being set to 15ftlbs doesnt mean it's accurate. maybe it didnt actually "click" untill 20, tho that shoudlnt normally be a problem.
of course, they coudl just be a bad batch of bolts too.
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Braiot
Novice Class
Posts: 77
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posted July 12, 2003 06:40 PM
Is there a good way of testing the accuracy of the wrench?
The only way I can think of is to compare it with another one, which I don't have.
Now I'm a little worried that maybe all the other bolts I tightened may be too tight as well.
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12RPilot
Pro
Posts: 1094
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posted July 13, 2003 04:41 AM
Chuck the torque wrench in a vice (pad it however you want) and hang 15 pounds off a one foot offset and get a click. Since 1 foot offsets are rare, you could hang 30 pounds off a 6" offset or 45# off a four inch, etc. Of course, you need to know that your weights are pretty close to being right.
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Braiot
Novice Class
Posts: 77
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posted July 13, 2003 02:17 PM
I don't care what anyone says about you 12RPilot, you're a good guy in my books.
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12RPilot
Pro
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posted July 13, 2003 02:34 PM
LOL. Well if you decide to go that route, let me know. I'll give some more detailed instructions for keeping it an accurate check up.
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12RPilot
Pro
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posted July 13, 2003 03:08 PM
Edited By: 12RPilot on 13 Jul 2003 16:10
Couldn't get an image to post. Damn!!!
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Braiot
Novice Class
Posts: 77
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posted July 13, 2003 07:22 PM
Well I just tested it out at 15 ft-lbs. I used a 6 inch extension with 30 lbs on the end. Accuracy is out about 2 ft-lbs at this setting. But it's out on the loose side. The wrench would break at 17 ft-lbs.
So there is no way that I overtighened those bolts. And I checked the wrench immediately after I twisted the bolt off to make sure I had it at 15, and I did.
I'm really at a loss here.
Thanks again for the help and yes, I'd be interested in the check up instructions if you have them handy 12RPilot.
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frEEk
Administrator
ummm... yeah
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posted July 13, 2003 07:54 PM
Braiot, i'm not sure if u didnt understand what the previous posts suggested or if u just dont think they are accurate, but here are two possibilities already mentioned:
1. the bolts were overtightened EARLIER, like at the factory or at the dealer, and that is what did the damage. the bolt just decided to wait until now to break
or
2. the bolts were simply a bad batch, so they failed well below where they should
i'm not saying either one of these scenarios is what actually happened, but they are 2 very real and probably rather likely possibilies. i really wouldnt worry or think about it too much. from what u'v described, i doubt it was your doing.
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flite leader
Zone Head
Posts: 651
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posted July 13, 2003 08:55 PM
nobody is sayin you are doing..... or did anything wrong
im with Zhooligan on this one
another poster(known for wringing nutz) questioned proper torque methods
at the lower end even with a wrench that "breaks'
its very easy to wring one off or over torque
i suggested he set up a "block"
of commonly used bolts & tighten a few b4 doing an engine
or forks or whatever
just to get a proper feel for it
.... just a suggestion as many have broken bolts or studs in
or on engines....... & Then have to do much more work $$$$$
to then get it fixed & right
get 4 new ones..... dont lube them
take you time
youll get it right
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Braiot
Novice Class
Posts: 77
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posted July 13, 2003 09:21 PM
Hey Freek, I'm only trying to narrow down all the possibilities, which I think I've done. Now that I know that my wrench is a little on the light side (at 15 ft-lbs) the only other possiblility is what you described.
More than likely, whoever assembled the forks overtightened them.
I'm going to get new bolts tomarrow, I will post results
Thanks for the help.
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frEEk
Administrator
ummm... yeah
Posts: 9660
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posted July 14, 2003 12:41 AM
cool cool. hope the new bolts behave!
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ScaredyCat
Expert Class
Posts: 201
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posted July 14, 2003 05:04 AM
One thing worth considering is if you used grease on the threads - in industrial applications different torque figures are given for un-lubed, greased and coppergreased threads. (for the scary high tensile stuff they actually hydraulically stretch the bolts before doing the nuts up.... eek).
Apart from probably not lubing the bolts in the first place, any given torque will relate to a much higher rtensile stress on a lubricated fastener.
So you can snap a bolt a lot easier if you lube the threads beforehand.
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12RPilot
Pro
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posted July 14, 2003 06:39 AM
Edited By: frEEk on 14 Jul 2003 20:26
I was just going to attach this pic:
It sounds like you have it figured out.
[edit: fixed link]
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Braiot
Novice Class
Posts: 77
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posted July 14, 2003 07:24 PM
Ok, I found out what the problem was. All I needed to do was look and I would have had my answer before I originally posted.
Whoever assembled the forks mashed up the threads a bit on the right clamp. The bolts still screw in straight, it's just a little tougher, so more friction.
The moron probably overtighened them as well.
The new bolts went in just fine with no problems.
Seeing how the bike is new I automatically assumed it was something I did wrong. Because everybody knows that all the people at the factory and dealerships love their job and treat all bikes like they would their own, right?
I can't see the pic 12RPilot. It gives me an error.
Later
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