Rear sprocket install disaster

[petshark]

I've just found 2 threads on this forum concerning the same thing.

The 80 Nm / 59 lb ft in the manual is too high. I read that it might work with new nuts but it doesn't say in the manual that they need to replaced. I tried to prepare really well, saw many videos, read the section in the manual a few times and set to work installing both sprockets and chain. Front sprocket install and chain breaking went well. Then the easy part: for the rear I did the criss-cross pattern while gradually tightening but.. the wrench never clicked. I started to worry and tried 40 Nm, it clicked just fine on all nuts. I figured it just needed to be tighter untill one or two started loosening and my worst fears became reality: stripped. Couldn't believe it. I'm learning many hard lessons with this bike... this time it's "don't trust the manual".

This nut actually sits a little higher on the stud than the others. It started turning the stud instead. While I could get it back out, it took the stud with it which to me indicates that the nut is really tight and the stud has stripped the aluminum threads in the hub (200 euro's 😮). In the other threads people talk about stripped nuts so I still have hope but not a lot. If you zoom in on the stud the threads seem stripped  as well so could it be that the hub is somehow stronger than the stud? Can't be, right? That would be great news of course.

Any insights are much appreciated as always.

Tomorrow is a holiday so no deliveries until at least monday. That day I happen to have a master course that I have really been looking forward to and paid for so I need the bike. So I've just epoxied the stud in place and will try all nuts tomorrow with a lower torque setting and if they are all holding I will install the wheel and check it often.

[johnmark101]

This really stinks.  I am not sure but I think I may have stripped a few when I did my new chain and sprockets.  They all seem to be holding fine.  However I was using the factory specs and the original nuts and the torque wrench would not click off.  So I stopped and checked them for tightness with a standard wrench and socket and they felt secure.  I keep an eye on them and will probably end up in the same situation as you in about 25,000 miles when I need to replace them again.  In the meantime all seems okay.    

Edited May 12, 2021 by johnmark101

[petshark]

5 minutes ago, johnmark101 said:

This really stinks.  I am not sure but I think I may have stripped a few when I did my new chain and sprockets.  They all seem to be holding fine.  However I was using the factory specs and the original nuts and the torque wrench would not click off.  So I stopped and checked them for tightness with a standard wrench and socket and they felt secure.  I keep an eye on them and will probably end up in the same situation as you in about 25,000 miles when I need to replace them again.  In the meantime all seems okay.    

That's great to hear. Well, not really but you know what I mean. Thanks!

[roadrash83]

I will usually take a micro torch or heat gun to the nuts, to soften up the thread lock before removing them. seems to work well.

[Salish900]

So what's the wisdom of what torque to use on these things if the manual is too much? 

[peteinpa]

Gave my opinion previously, wasn't too popular. 

For future reference, and you're not the only one, I'm speaking to all.  This IS a tech. question. It belongs in the garage where others in the future can find it.

[PhotoAl]

It's been a while and I'm getting older but seems like I remember something about wrong torque in the manual for sprocket bolts when I changed the sprockets on my 2004 FZ6 ten or eleven years ago.  I went with a SuperSprox rear sprocket on that bike which was nice.  

[andz]

15 hours ago, PhotoAl said:

It's been a while and I'm getting older but seems like I remember something about wrong torque in the manual for sprocket bolts when I changed the sprockets on my 2004 FZ6 ten or eleven years ago.  I went with a SuperSprox rear sprocket on that bike which was nice.  

I had a 2004 FZ6 and when I changed the sprockets I torqued to manual spec and it was fine.

Edited May 13, 2021 by andz

[peteinpa]

54 minutes ago, andz said:

I had a 2004 FZ6 and when I changed the sprockets I torqued to manual spec and it was fine.

but what was that manual spec??

[piotrek]

I used a low torque impact driver and it gradually hammered the nut off without drama. I do agree that the torque value reads insane for the size of the fastener, but I did it to spec, using sequence as described in the book, and in steps.

Edited May 15, 2021 by piotrek

[Dodgy Knees]

I only use torque wrench on Axles, thats about it. Screwing bolt's into casings, calipers etc is best done by feel,   ime.  👍

[JonnyB]

Rather than buy a new hub, can you use helicoils or similar to repair? I have done this on several alloy parts over the years. 

[tktplz]

5 hours ago, Dodgy Knees said:

I only use torque wrench on Axles, thats about it. Screwing bolt's into casings, calipers etc is best done by feel,   ime.  👍

That's me. I do mine by feel unless it's motor bolt specs.

[roy826]

Most if not all torque wrenches can be off +/- 5-6% so that is one way to approach using one. I personally only use one on axle bolts (not the 108 yamaha requires on rear axle nut) and that is about it. I go by feel from many years of wrenching on motorcycles with mostly aluminum nuts bolts and pot metal hardware.

[petshark]

5 hours ago, JonnyB said:

Rather than buy a new hub, can you use helicoils or similar to repair? I have done this on several alloy parts over the years. 

I was just looking into that, yes. I'm still pretty new to wrenching so learning as I go along. That seems a good option. I can also try to source a hub from a crashed MT09 (I suspect they crash more often than Tracers and it's the same part)

7 hours ago, Dodgy Knees said:

I only use torque wrench on Axles, thats about it. Screwing bolt's into casings, calipers etc is best done by feel,   ime.  👍

I just learned this the hard way. I've been using the torque wrench on a lot of stuff because I thought that way I could develop the feel, but if it's all too tight I might as well forget it. Talking about the axle, that should be 150 Nm but that is also way too tight according to many so I did 100 Nm. At least I read about that before I ruined the aluminum wheel alignment block.

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.

Could we perhaps make a sticky post with community torque settings and/or warnings for high torque values? If you're like me and don't have the experience it sucks to never be sure if you're going to strip a bolt or if it might come loose and potentially cost you your life. That's an obvious downside from learning these things from video's and books, I wish there was a thing like community garages over here.

Edited May 14, 2021 by petshark
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