07 Sprocket, Bolts, or Hub Failure


54 replies to this topic
  • Dirty_Sanchez

Posted October 16, 2006 - 03:31 PM

#21

I stayed at a Holiday Inn Express last night, performed two lobotomy's before noon, and am Thumpertalk's resident Loctite factory Rep.

No kidding.

I tell every new bike owner whether it's a dirt bike, or street bike to remove and reinstall every nut and bolt you can access and put either a red or blue threadlocker on it, then reassemble.

On dirt bikes/dual-sports, blue will do it all for us. I rarely if ever use a red threadlocker unless I'm conducting machinery reliability training at an industrial facility.

Apply threadlocker to every 6mm nut and bolt you can find in one sitting, then do the 8mm's, then the 10mm's, etc., on up to the axle nuts.

Do it, because going through a new or used bike like this could save your skin.

You could have been seriously hurt or worse if you weren't so lucky.

None of us wants a bike to come apart 40 miles from nowhere, or 40 feet in the air.

One piece bikes rule!

Dirty

  • Fastest1

Posted October 16, 2006 - 04:23 PM

#22

I would think Yamaha would work with you especially if you praise them first. It always seems to help. My suspicion leans towards chain tension. It would make sense since the bike squats heavily during acceleration and has the opportunity for the highest chain tension during that arc, This folds the sprocket over, breaks the hub and shears the bolts. Though I do use loctite for sprocket bolts, I rarely use it anywhere else. I rely on constant checking and rarely do I find anything loose. I use more antiseize than any other product. It definitely makes maintenance easier and never a seized nut or bolt. More accurate torque readings too!

  • RCannon

Posted October 16, 2006 - 04:26 PM

#23

I bought one of the faastco spoke wrenches just before getting my new yz. EVERY spoke was very loose...even before riding the bike. I believe the factory only tightens then as much as they can from the INSIDE of the rim. I dont believe a real spoke wrench is ever used on the bike. Or that a real human builds the wheel. Notice how the nipples are perfect????

The sproket??? Remember several years ago when a person had to use heat to get the stock bolts loose? What happened since then?

I almost completly removed ever part off of my bike when it was new. Still, I dont believe we should have to. I cannot help but wonder...If sproket bolts are coming lose after being "factory installed" whats next? Interal engine parts?

  • 02YZ426

Posted October 16, 2006 - 04:59 PM

#24

I bought one of the faastco spoke wrenches just before getting my new yz. EVERY spoke was very loose...even before riding the bike. I believe the factory only tightens then as much as they can from the INSIDE of the rim. I dont believe a real spoke wrench is ever used on the bike. Or that a real human builds the wheel. Notice how the nipples are perfect????

The sproket??? Remember several years ago when a person had to use heat to get the stock bolts loose? What happened since then?

I almost completly removed ever part off of my bike when it was new. Still, I dont believe we should have to. I cannot help but wonder...If sproket bolts are coming lose after being "factory installed" whats next? Interal engine parts?



This year so far... My handlebars came loose at the triple clamp, sprocket bolts backed off and yes my spokes could have been tighter from the factory. But this stuff should all be gone over anyhow and I don't blame Yamaha for poor workmanship. Its up to us to make sure the bike doesn't rattle apart, and loctite and basic maintenance is the simple solution. Should we have to do this? Yes, its called maintenance... some do more than others and the ones who do less run into these kinds of problems. At least Yamaha makes the toughest, most reliable engine in the market... and I wouldn't trade that for any bike.

  • yz375

Posted October 16, 2006 - 09:56 PM

#25

I own an 06 and just spent 300 + on a new oem hub, sprocket kit and aftermarket sprocket for this very reason.

My story is a little different though, i noticed my bolts loosened up badly and one was missing after my 3rd ride. I was always told you should replace them all if you come up short and other bolts are loose. I purchased a generic sprocket kit from Langston Racing and put a load of red loctite on each following the pattern you're supposed to. A couple of days later, my first ride back, 3 laps in, CLANK, I thought I blew my engine. Luckily I was coming out of a flat corner!!!! Every bolt was snapped, with two missing, my sprocket dug a nice chunck in the swingarm and chain guide. I can take pictures if anyone would like to see the parts a was able to locate.

I never even thought of bringing this to yamahas attention due to the set of bolts being aftermarket, however, this is apparently happening far too often. Like others have mentioned, i am just glad this didn't happen of a big hit, the track I ride is littered with them, i am very lucky!!!

  • Dirty_Sanchez

Posted October 17, 2006 - 12:29 PM

#26

I would think Yamaha would work with you especially if you praise them first. It always seems to help. My suspicion leans towards chain tension. It would make sense since the bike squats heavily during acceleration and has the opportunity for the highest chain tension during that arc, This folds the sprocket over, breaks the hub and shears the bolts. Though I do use loctite for sprocket bolts, I rarely use it anywhere else. I rely on constant checking and rarely do I find anything loose. I use more antiseize than any other product. It definitely makes maintenance easier and never a seized nut or bolt. More accurate torque readings too!


Anti-Seize is nothing more than metal dust and grease-best used in high heat applications. If you're good at context clues, anti-seize lubricates the threads as you are inducing a clamp load via use of a torque wrench, but it also lubricates the threads when times comes for coming apart-sometimes when it's not desired.

Anti-Seize and Threadlocker have almost identical "K Factors" aka lubricity. Clamp loads using anti-seize and threadlockers with identical grade fasteners and torque readings will be virtually identical.

The use of anti-seize on your bike hasn't jumped up and bitten you on the arse just yet, but I'll stick with my trusty blue threadlocker because it stops galvanic corrosion just like anti-seize AND it locks threaded fasteners together until I choose to remove them unlike anti-seize:thumbsup: .

Dirty

  • Ga426owner

Posted October 17, 2006 - 12:36 PM

#27

I own an 06 and just spent 300 + on a new oem hub, sprocket kit and aftermarket sprocket for this very reason.

My story is a little different though, i noticed my bolts loosened up badly and one was missing after my 3rd ride. I was always told you should replace them all if you come up short and other bolts are loose. I purchased a generic sprocket kit from Langston Racing and put a load of red loctite on each following the pattern you're supposed to. A couple of days later, my first ride back, 3 laps in, CLANK, I thought I blew my engine. Luckily I was coming out of a flat corner!!!! Every bolt was snapped, with two missing, my sprocket dug a nice chunck in the swingarm and chain guide. I can take pictures if anyone would like to see the parts a was able to locate.

I never even thought of bringing this to yamahas attention due to the set of bolts being aftermarket, however, this is apparently happening far too often. Like others have mentioned, i am just glad this didn't happen of a big hit, the track I ride is littered with them, i am very lucky!!!


you needed to swap out sprockets after you noticed the bolts were loose and minus one - the sprocket probably was galled - ovaled out holes

  • grayracer513

Posted October 17, 2006 - 01:12 PM

#28

Anti-Seize and Threadlocker have almost identical "K Factors" aka lubricity. Clamp loads using anti-seize and threadlockers with identical grade fasteners and torque readings will be virtually identical....I'll stick with my trusty blue threadlocker because it stops galvanic corrosion just like anti-seize AND it locks threaded fasteners together until I choose to remove them unlike anti-seize:thumbsup: .

Dirty

I agree with 90%+ of this, but not with using threadlockers on the chain adjusters, which is what Fastest1 was recommending.

  • Dirty_Sanchez

Posted October 17, 2006 - 01:17 PM

#29

I agree with 90%+ of this, but not with using threadlockers on the chain adjusters, which is what Fastest1 was recommending.


I'm with you Grey-

Chain Adjusters and the fork bleeders, and spokes are the only place you don't find a threadlocker on my bike.

Cheers for Now-

Off to do two Loctite workshops in northern Louisiana tomorrow.

Dirty

  • RCannon

Posted October 17, 2006 - 02:27 PM

#30

On the loctite subject......has everyone seen the loctite packaged just like chap stick?? It is a lot easier to deal with than the older dropper style. This new method op packaging rocks.

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • FlynRyn

Posted October 17, 2006 - 03:32 PM

#31

YamieRider411
It is a shame that this happened, but personally I do not see a defect.
I know you say you checked these bolts (which I do not doubt) but unless you actually used a torque wrench, there is no way you can be sure they were tight enough. The sprocket bolts should be torqued at 30 ft. lb. As a reference a typical 8 x 1.25 bolt would normally be torqued at 11 ft-lb so the drive sprocket requires 3 x the STD torque. The fact that the sprocket bolts are missing and one portion of the hub is damaged means the bolts became loose then backed out, which eventually broke the hub. What I have seen on my bike is that the tapered bolt seats to the sprocket requiring a retorque as within as little time as 15 minutes. If you look at the manual the break in procedure asks you to inspect all hardware as per torque check points after the break in is complete, approximately 20 minutes. The pre ride inspection then says to check these bolts before each ride thereafter. Maybe use a longer wrench to get a bit more leverage or tighten them a bit more than you did and I bet you never see this problem again. I hope Yamaha helps you out on this one as that’s one expensive lesson.

Quote
RCannon “I bought one of the faastco spoke wrenches just before getting my new yz. EVERY spoke was very loose...even before riding the bike. I believe the factory only tightens then as much as they can from the INSIDE of the rim. I don’t believe a real spoke wrench is ever used on the bike. Or that a real human builds the wheel. Notice how the nipples are perfect????

The sprocket??? Remember several years ago when a person had to use heat to get the stock bolts loose? What happened since then?

I almost completely removed ever part off of my bike when it was new. Still, I don’t believe we should have to. I cannot help but wonder...If sprocket bolts are coming lose after being "factory installed" what’s next? Internal engine parts?”


Faastco is a preset torque wrench which is set at 48 in.lbs (OE is 26.4) this is above the factory torque spec so its no wonder each spoke was loose.

  • mmbasa

Posted October 17, 2006 - 04:33 PM

#32

So what is the proper way to check the bolts? From the inside or the outside, on the nuts or the outside on the bolt?

  • grayracer513

Posted October 17, 2006 - 06:04 PM

#33

In any applicaion such as this, turn the nut only whenever it's practical to do so.

  • Ga426owner

Posted October 18, 2006 - 06:20 AM

#34

In any applicaion such as this, turn the nut only whenever it's practical to do so.


I have found that once you locktite w red on the sprocket bolts and nuts....I have never had to break the seal to "recheck torque".....maybe another reason this has not happened again, until time to replace sprocket....if you break the seal......get your locktite out again and reaaply...otherwise....chances are yours will loosen up again and again until failure occurs...:devil:

  • RCannon

Posted October 18, 2006 - 07:20 AM

#35

Faastco is a preset torque wrench which is set at 48 in.lbs (OE is 26.4) this is above the factory torque spec so its no wonder each spoke was loose.[/QUOTE]

My manual says 30 on the spoke nipples. Even though the Faastco wrench is non-adjustable, it really is. I called faastco and they told me how to bacvk the preset torque off. I had it set for @ 30-33 lbs. My spokes were not even close. It was at least 1/2 turn to get this measurement.

They strongly suggested 48in/lbs on the phone. I took them up to this after I brought them to 30 first. Never a wheel issue. The rims are as straight and true as the day I bought the bike. The spokes have never loosened again.

I have alos seen many recommendations to replace the sproket bolts/nuts after removing them. Something about the nut losing its locking abilities after being removed. If this is true, are we not defeatign the purpose of the nut bu removing it to add loctite?

  • grayracer513

Posted October 18, 2006 - 07:55 AM

#36

I have alos seen many recommendations to replace the sproket bolts/nuts after removing them. Something about the nut losing its locking abilities after being removed. If this is true, are we not defeatign the purpose of the nut bu removing it to add loctite?


Locking nuts rely on friction in one way or other to hold in place. "By the book", they are replaced with new one every time they are removed. They are typically made in one of four ways: 1) A nut with a tough plastic insert on the end with the hole in the insert being smaller than the threads, 2) A metal insert in place of the plastic, 3) the nut is deformed at the top end during manufacturing so that the threaded hole is out of round, or 4) the nut is cross drilled and a plastic or soft metal pin is run in just higher than the threads.

Regardless of the type, they all work best the first time they are installed, and, again, "by the book", they should never be reused. But, you can use your own judgment on that (be honest with yourself about your own judgment). If the nut has a fair amount of drag as it goes on the second or third time, it should work. I've reused the bolts/nuts on my '03 at least twice, and they're still there, still tight. They have no Loctite on them either, although I find nothing wrong with recommending its use.

The red stuff is the strongest, but it's not as tenacious as some say, IMO. In fact, bolts that are prone to sticking in place are often easier to remove with threadlocker applied because of the lubricating and anti-corrosive qualities Dirty mentioned.

And Loctited fasteners CAN be reused without re-applying any, but like a lock nut, the threadlocker is less effective this way than it was to start with, and even more so than a used nut. The blue is quite a bit more reusable than the red.

The best insurance, with or without lock nuts or threadlockers, is clean, dry threads, and properly seated, clean parts.

BTW, Here's a Good Buy on grade 10 stainless bolts (scroll down).

  • FlynRyn

Posted October 18, 2006 - 08:18 AM

#37

My manual says 30 on the spoke nipples. Even though the Faastco wrench is non-adjustable, it really is. I called faastco and they told me how to bacvk the preset torque off. I had it set for @ 30-33 lbs. My spokes were not even close. It was at least 1/2 turn to get this measurement.

They strongly suggested 48in/lbs on the phone. I took them up to this after I brought them to 30 first. Never a wheel issue. The rims are as straight and true as the day I bought the bike. The spokes have never loosened again.

I have alos seen many recommendations to replace the sproket bolts/nuts after removing them. Something about the nut losing its locking abilities after being removed. If this is true, are we not defeatign the purpose of the nut bu removing it to add loctite?


My apologies RC, I assumed you owned and were talking about a YZ or WR which have been 2.2 ft.lb (26.4 in.lb) since at least 99.

How do you adjust the wrench btw? I am interested to know that.

Also in reference to loctite, quite a few engineers I know say that if a bolt or nut is properly torqued it will never require any form of bonding or anti-loosening agent.

There are still just some items I would always loctite even knowing that though.

  • motobark

Posted October 18, 2006 - 10:52 AM

#38

Hey Gray, have you ordered anything from Quality Smart lately? I was going to order some Ironman sprockets from them the other day and saw the message on their site that said they're not taking any new orders.
I've ordered from them before, they're cheaper than DirtTricks for Ironmans.

  • grayracer513

Posted October 18, 2006 - 11:30 AM

#39

No, I haven't. It's a one-man show run by a TT member, and I know he's just recently had a baby at his house, so it could be that he just doesn't have the time for it. Too bad, those are good deals.

  • Jaycycle

Posted October 18, 2006 - 11:41 AM

#40

Wow, thats nuts. I have never seen that happen. Did it damage the swingarm at all?





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