06 Yz 450 Hub Broke


42 replies to this topic
  • jamiehughes

Posted June 18, 2007 - 12:46 PM

#1

well i've read on here about it happening, and i've always been pretty anal about my sproket bolts, and my aftermarket sprocket has been on for over a year, with locktite and bolts were checked 3 weeks ago when i put on a new tire, none were loose and i didn't put any torque on them as i didn't want to break my loctite loose. i was riding sat and after a few rides out, hub came apart after landing off of a jump, let me tell you it wasnt pretty as the wheel locked up and i went over the bars into the face of the next double. so now the hub is at my local dealer to see if and what yamaha will do. the holes don't look wallowed out at all to me, the parts guy said that they stock the hubs, then i told him that if they weren't gonna take care of it i didn't want another yamaha hub, to which he replied well they arent having any problems with the new hubs. if they are having probs with the 06's why isnt there any notices on these? i post what they decide to do. and maybe get some picks up here if they don't take care of it. it sure made short work of my ironman sprocket,bent it like a pretzel.:thumbsup:

  • Ga426owner

Posted June 18, 2007 - 01:13 PM

#2

That stinks man....sounds like you did all the right things to keep it from detonating. I am curious if they will do anything but not too hopeful....one alternative for you is that Motosports is blowing out Talon hubs and Excel rim assembled with Bulldog spokes......front 350.00 rear 450.00 And MSR is selling Ironman sprockets for 79.00

  • SC_Spode

Posted June 18, 2007 - 01:18 PM

#3

it sure made short work of my ironman sprocket,bent it like a pretzel.:thumbsup:



Was this one of those sprockets without the inner ring?

  • grayracer513

Posted June 18, 2007 - 03:15 PM

#4

At the risk of being overly blunt, your chain was too tight. It had nothing to do with sprocket bolts or LocTite, or any of that.

  • jamiehughes

Posted June 18, 2007 - 03:42 PM

#5

good, that means yamaha should warranty it as they told me as long as the bolt holes werent rounded out they would warranty it. my chain must've been to tight for the last 10 months and 30 hours ago as that was the last time i changed the adjuster screws,as i put an aftermarket chain on there right after i bought it and i went by yamaha's 2 1/2 inch rule, guess i should have that thing slapping loose with my size.

  • grayracer513

Posted June 18, 2007 - 04:04 PM

#6

The chain tension has to be set with the bike on the stand, and the chain must be able to be pulled up to a point 1.9-2.3" above the rear slider bolt. You should be able to push the chain down against the swing arm at or just behind the rear slider bolt.

When set like this, they look loose, so many either don't measure at all, and go by when it looks right, or decide that the book must be wrong. The result is that the chain runs out of slack as the swing arm passes over center, and the resulting force breaks the sprocket flange off the hub.

It's also important to realize that the use of larger than stock sprockets will make it necessary to add to the measurement dimension used in the manual.

Your weight is of no consequence to the equation. The only question is whether there is slack as the swing arm passes through the point where the centers of the out put shaft, swing arm pivot, and axle are in line with each other, as this is the point at which the axle is the farthest from the front sprocket.

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  • Yamahafan

Posted June 18, 2007 - 06:44 PM

#7

Gray,

You are scaring me. I ran out to the garage and checked my slack again. On the stand it is exactly 2 inches above the rear TM Designworks slider bolt when pulled tight, but it is a ways from being able to touch the swingarm behind the slider. Could you post a picture of your measurement?

  • grayracer513

Posted June 18, 2007 - 07:13 PM

#8

I run the '06 at 2.25 - 2.375" with the standard sized sprockets on the bike. I have a wood block that I cut with a step in it so that it measures 2.2 on one end and 2.4 on the other. When I set this block on the slider, the short side should fit, and the tall side should not. If you want to be absolutely sure that you're not running the chain too tight, do as suggested in the link I posted. Then, you'll know.

  • greentyler

Posted June 18, 2007 - 07:57 PM

#9

the chain should touch the swingarm behind the slider bolts?!

i've had a problem with mine being too loose too... have had it jump a tooth on the back sprocket resulting in the chain being so tight that i couldn't kick it over and the back suspension was completely locked up as a result... all this on a sand ride about 10 miles from our truck and the nearest set of tools!

personally, i'd trust my chain being a little tighter rather than too loose.

  • SC_Spode

Posted June 18, 2007 - 08:15 PM

#10

personally, i'd trust my chain being a little tighter rather than too loose.


You absolutely don't want to do that.

I've seen a set of cases snatched apart because the chain was too tight. When the swingarm swung through its arc and the chain touched the upper roller, it got even tighter and it yanked on the countershaft so hard that it pulled the cases apart. :thumbsup:

I imagine it was quite expensive to repair.

:thumbsup:

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  • greentyler

Posted June 18, 2007 - 08:19 PM

#11

haha, thanks for the advice!

but i don't mean THAT tight, i mean tight enough so its not completely sloppy... and within' spec.

  • kstutzman

Posted June 19, 2007 - 06:11 AM

#12

06 YZ450 also. Ripped the sprocket right off the hub. Tore one of the flanges off the hub. The rest of the bolts are gone. Do they just shear off when the hub cracks?

  • jamiehughes

Posted June 19, 2007 - 06:54 AM

#13

my chain definitely wasn't too tight. i had actually about 1/4 of an inch more than what grey specified. but i'm sure that some will still be able to see it as my fault just because they haven't had these problems yet.

  • jamiehughes

Posted June 19, 2007 - 06:58 AM

#14

06 YZ450 also. Ripped the sprocket right off the hub. Tore one of the flanges off the hub. The rest of the bolts are gone. Do they just shear off when the hub cracks?


maybe there is actually a problem with the hubs, as my dealer even told me that they arent having problems with the new hubs like they were with the old ones. so there mustve been some problems for him to say that. one of my other buddies had a problem with the bearings in his hub, after just 5 hours on the bike you could pull the bearings out by hand, they were really sloppy in the hub.

  • andy250

Posted June 19, 2007 - 07:43 AM

#15

Add me to the growing list of bad hubs. The bearing has spun in mine, and there is a ton of lateral play as well. I can almost pull the drive side bearing completely out of the hub by hand. Lack of maintenence or improper chain slack are not an issue here either. My chain is kept at +/- 2" of slack, and bearings are regreased religously. There absolutely has to be a problem with these hubs. Even with overly tight chains we shouldn't be seeing this frequency of failure.

I just ordered up an excel/talon wheelset from motosport.com for peace of mind.

  • grayracer513

Posted June 19, 2007 - 07:56 AM

#16

The bearing pocket issue IS a flaw in the hubs affected by it. There MAY be a flaw that contributes to the breaking off of sprocket flanges. But the thing I see is simply this:

This particular problem really began with the '06. The '06 has a different shaped swing arm, and a lowered lower chain roller. Both of these things cause the chain to need more slack on the stand than any earlier YZF, and to look even looser than that. People are always telling me that my chain looks loose to them, and I've seen the same comment made about other '06's here on this sight when someone posts a picture. Given that, I believe that most of these failures are brought about by excessively tight chains, and that there are several more out there waiting to happen.

  • andy250

Posted June 19, 2007 - 08:07 AM

#17

The bearing pocket issue IS a flaw in the hubs affected by it.


Can you elaborate on this flaw? Bad batch of castings? Why are previous and later models not affected, but only the '06 model? How can this flaw NOT also be the cause of the catastrophic failures others are seeing?

I'll try taking the hub to my local dealer and see what they say...

  • jamiehughes

Posted June 19, 2007 - 08:50 AM

#18

well after my dealer sent pics to yamaha, they said they are going to warranty my hub and spokes, my dealer said he has warrantied like 5 or 6 of these already. i hope others don't start seeing problems like mine, especially when going over a jump like i was when it broke.

  • msgbean

Posted June 19, 2007 - 09:04 AM

#19

Personaly I am inclined to blame the Ironman sprocket. The same thing happened to me and my buddy. We both had Ironman sprockets. Both broke after landing from a jump while on the gas. My theory is that under extreme pressure the skeleton frame of the ironman folds to one side creating the chain of events which leads to the broken hub. I will never buy another one.

  • grayracer513

Posted June 19, 2007 - 09:43 AM

#20

Can you elaborate on this flaw? (loose bearings) Bad batch of castings? Why are previous and later models not affected, but only the '06 model? How can this flaw NOT also be the cause of the catastrophic failures others are seeing?

If the hub that breaks the sprocket flange off has no problem with loosening or deformation of the bearing pockets, as they often do not, then it had nothing to do with the failure.

As far as I know, the bearing problem is the fault of a casting defect in the hubs involved.





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