Rear sprocket install disaster

[andz]

On 5/13/2021 at 10:15 PM, peteinpa said:

but what was that manual spec??

100Nm and I have an expensive Gedore torque wrench.

[whisperquiet]

I just loosened my OEM tightened sprocket nuts just for kicks…..the nuts were easy to break loose and then were re-torqued to 43 lb ft which seemed more than adequate.  My GT currently has 12,200 miles on it.

Edited May 15, 2021 by whisperquiet

[piotrek]

On 5/14/2021 at 7:08 PM, Warchild said:

Nope, I would treat the oem steel sprockets the very same way - 43 ft-lbs, not any more than that

I think @skipperT might have meant Ti fasteners... i.e. the torque values listed for a steel fastener would no longer apply anyway.

Edited May 16, 2021 by piotrek
sp

[skipperT]

20 minutes ago, piotrek said:

I thing @skipperT might have meant Ti fasteners... i.e. the torque values listed for a steel fastener would no longer apply anyway.

Yes. Thanks for clarifying. 
-S

[Warchild]

Wrong answer, gents. Let me clarify for both of you:

Whether the sprocket nuts in question are the current OEM steel nuts from the factory, or the Tek 5 Titanium fasteners I posted up, I would/am taking both of these to 43 ft-lbs of torque, and no higher. Regarding the Tek 5 Ti fasteners, they will also get a small dollop of copper-based anti-seize near the base of the stud threads, then I'll take them to just 43 ft-lbs.  👍

If you want to take these torque values higher on your bikes, no problem, have a blast. Hopefully they won't go all petshark-ed [tm] on you.    😃 

[piotrek]

2 hours ago, Warchild said:

Whether the sprocket nuts in question are the current OEM steel nuts from the factory, or the Tek 5 Titanium fasteners I posted up, I would/am taking both of these to 43 ft-lbs of torque, and no higher.

LOL... okay, so let's just get past your Ti nuts and assume that they are appropriate grade for the application. I think the general point was that the torque value in the book is there for a specific fastener (material/size/shape), in order to achieve some clamping force. You could use a different fastener, and still be able to torque it down to the specified value, but the clamping force (what really matters) could be different because material properties are different.

[petshark]

On 5/15/2021 at 3:30 AM, piotrek said:

I don't remember if my bike had thread locker on the stud threads (nut side) from factory, but according to the service manual it is a dry assembly. Do I see thread locker just under the nut in the photo, or is that just a bit of corrosion?

Interesting read on torquing fasteners from Yamaha here. Marine engine talk, but applicable just the same.

All the studs on mine had the white stuff on that you see in the OP. Judging from the location I don't think it can be corrosion, can it? And white corrosion would mean that these studs are aluminum which I don't think they are. But I'm really not sure about any of this.

But if I had to guess I think that there was some kind of none-standard threadlock on both sides of the stud even though it is not in the service manual. That stuff or slivers of stripped threads in the nut actually caused the stud to start rotating in the hub before the nut was all the way down.

And thank you for that link. That is an interesting read indeed, and it sure gives the impression that Yamaha does know what they are doing with these specs.

Another anecdote; the dealer where I finally found the nuts was telling me on the phone that 80 Nm is not right and that I probably had a fake manual. I challenged him to look it up and when I got there, he admitted his mistake and said that he tried it on an MT09 he had in the shop. For some reason he even went to 90 Nm, and he didn't have any issue, so he stood behind the factory spec and also had no idea why mine petsharked. I told him about the other "cases" and he had never heard of this happening.

Edited May 16, 2021 by petshark

[peteinpa]

Hmmmm...After he torqued to 90NM did he remove the nut?

[peteinpa]

Watched this:   

Besides the hilarity of it, he beats the  #### out of it, and being Harbor Freight items, you can't argue with both giving the same torque #'s even after all the abuse.

The digital one is only $30. 

[petshark]

57 minutes ago, peteinpa said:

Hmmmm...After he torqued to 90NM did he remove the nut?

I don’t know. I hope he didn’t use a clients bike. 
 

42 minutes ago, peteinpa said:

Watched this:   

Besides the hilarity of it, he beats the  #### out of it, and being Harbor Freight items, you can't argue with both giving the same torque #'s even after all the abuse.

The digital one is only $30. 

amazing.. and fun to watch. 

Edited May 16, 2021 by petshark

[skipperT]

14 hours ago, piotrek said:

LOL... okay, so let's just get past your Ti nuts and assume that they are appropriate grade for the application. I think the general point was that the torque value in the book is there for a specific fastener (material/size/shape), in order to achieve some clamping force. You could use a different fastener, and still be able to torque it down to the specified value, but the clamping force (what really matters) could be different because material properties are different.

This. And another reason why you can’t propose to use a lower/higher torque value because a number is higher or lower across different bikes for similar components. And that it’s ok to go with a smaller number because other bikes do it. It’s not that simple @peteinpa. The materials, size, and clamping load required for one bike are not the same as for another.  

Well stated, @piotrek.  

@Warchild, to each their own. I don’t agree with your decision but I’m not riding your bike.

You (and anyone reading this) accepts the risks associated with changing the fastener type from stock and torquing it differently than spelled out in the service manual. 

-Skip

[Warchild]

3 minutes ago, skipperT said:

I don’t agree with your decision but I’m not riding your bike.

 

"This", as you say.  😁

I'll go ahead and go with my 30+ years of experience in these matters, vice what an engineer writing a service manual claims it should be. I'll choose not to blindly follow a spec when I know it's not reasonable.  Like you say, to each their own, but I know I won't be having studs go all petshark on me, and neither will the wheel come unmade at speed. 

Happy riding. I am off to Portland to pick a 4.2 aux fuel cell - on the XR, since the Tracer's forks have not returned yet

[peteinpa]

@skipperT   Did you watch the above video I linked? $10 torque wrench holds up to serious abuse and still works.

When you go digital it uses strain gauges, sounds more solid state. Same way rifle barrels are proof tested. For $30 I might get one. My present Torque wrench is an old Sears click type I think is still accurate.

[tktplz]

On 5/14/2021 at 7:32 AM, petshark said:

Torque values gave me peace of mind but that's all over. I'll try to go back to developing a "feel", it's what I always did before. But working on a motorcycle is serious business as there's a lot less margin for error so I tried to follow the book.

Yes on frame, oil drain, axle etc. I have developed a "feel" for what is correct. When working inside an engine I use a torque wrench. And have them calibrated every 2 years or so for piece of mind. I've hardly done any internal work on engines since my last 2 bikes were Kawasaki 1100 cc motors. No removing cams to do valves, very simple actually but that's another conversation. Haven't looked in the huge FJ09 factory manual yet to see if a special tool works like on the VMax 1200. Or if I pull the cams. If so it's time to find a place to have my 2 torque wrenches calibrated. But yeah, inside the engine torque values respected, frame exterior can be done mostly by feel. 

[piotrek]

8 hours ago, peteinpa said:

Watched this:   

Besides the hilarity of it, he beats the  #### out of it, and being Harbor Freight items, you can't argue with both giving the same torque #'s even after all the abuse.

The digital one is only $30. 

That was funny, and strangely reassuring LOL. I try not to use these things for values near the edges of scale. Would be good to see this test for extreme low and high values. Still want to upgrade my 1/4" drive tool one day.