Broken Bolt

[HD4ME!]

In your manual does it state that it should be removed to replace the tire?

I dont know what the manual says but I do know what the Stealer told me. They said it was not removed when the tire was replace. I am really starting to think it was. It makes sense that this would happen if it was removed and the bolts were reused. However it has been ~22 months but only ~5k miles.

 

[R_W_B]

... ... ... ... Would someone show the complete assembly, as shown in the manual, to the rear wheel? ... ... ....

Don I don't have the manual but maybe this will help until someone gives a more detailed explosion of it.

No 17 is the bowl compensator, and 12 is the rubber

 

[HDDon]

I've seen this one and I understand the makeup, I am not to clear how the assembly mounts at the wheel. Are the bolts thru the bowl and mounted to the wheel? I would really like to see one of the pictured failed bolts under a scope as they look like more metel fatigue than sheer, also I don't think anyone has mentioned damage to the swingarm.

 

[IBA Harley]

Glider you are right, we only talk about the ones that fail.

I guess that is true. I've never complimented the 3 good tires on my car when 1 was flat.

 

[Hoople]

Now I am really confused. If you look at picture #1 on entry point 25 of this thread, it looks like the remains of the sheared off bolts is still in the rear pulley. But how can that be because according to the picture in entry point #52, the 5 bolts don't screw into the rear pulley. The picture of the 5 sheared bolts (entry point 25), still have the heads and captive washers. So what are small pieces of bolts doing in the rear sprocket?

Is the picture in entry point #52 a picture of the improved version and not what came on the 2008 (generation 1) from the factory.?

 

[R_W_B]

... ... .... also I don't think anyone has mentioned damage to the swingarm.

Now I am really confused. If you look at picture #1 on entry point 25 of this thread, it looks like the remains of the sheared off bolts is still in the rear pulley. But how can that be because according to the picture in entry point #52, the 5 bolts don't screw into the rear pulley. The picture of the 5 sheared bolts (entry point 25), still have the heads and captive washers. So what are small pieces of bolts doing in the rear sprocket?
Is the picture in entry point #52 a picture of the improved version and not what came on the 2008 (generation 1) from the factory.?

HD4ME in addition to the questions above, I did not see where anyone addressed (or dimissed) Dr Evil's question about
..........If the rear bearing failed, could the engine have enough torque at speed to rip the pulley off?

We are all curious for any input you can give us.

 

[Hoople]

If the rear bearing failed, could the engine have enough torque at speed to rip the pulley off?

In my opinion, I seriously doubt it. To shear off 5 TIGHT (tight) bolts in one shot would take a whole lot more torque than these engines have. I realize it is not the same thing by comparison but look at it with proportion... If a 600 H.P. Viper can't shear off 5 lugs nuts when you pop the clutch at 4000 RPM, we are not shearing our bolts either. I have seen muscle cars shift 12" slicks on the rims before a wheel lug broke. Has anyone ever seen a TIGHT wheel shear off a car even when they had 1000 H.P. I never have. But if the lug nuts were loose, forget it. You will rip them out very easily. The lugs can not absorb the "running start" impact.

I really think the elongated slots were no match for the bolts.

 

[Dr.Evil]

In my opinion, I seriously doubt it. To shear off 5 TIGHT (tight) bolts in one shot would take a whole lot more torque than these engines have. I realize it is not the same thing by comparison but look at it with proportion... If a 600 H.P. Viper can't shear off 5 lugs nuts when you pop the clutch at 4000 RPM, we are not shearing our bolts either. I have seen muscle cars shift 12" slicks on the rims before a wheel lug broke. Has anyone ever seen a TIGHT wheel shear off a car even when they had 1000 H.P. I never have. But if the lug nuts were loose, forget it. You will rip them out very easily. The lugs can not absorb the "running start" impact.

I really think the elongated slots were no match for the bolts.

Looking at the pics I have to now agree with Hoops thoughts on the oblong holes indicating that the assembly was loose and torquing back and forth for quite some time. Keep in mind that all 5 bolts heads were found at the failure location so the swing arm did not knock them off one at a time and they would not loosen up at the same rate to knock them off in one shot, and further moor the heads are not damaged.

Did the bolt heads get captured inside the bowl?

What would be great, would be to remove each broken stud and see how far out each one was. At that point you could also check for Loctite on the threads. I have to say if the money was coming out of my pocket, I would be all over finding the root cause.

 

[Dr.Evil]

Looking at this from a very top level. If the bolts, through bolt all that hardware to the wheel they must be at leats 2-3 inches long. They seam to me to be too small a diameter bolt to clamp that thickness of assembly. Just slightly under torqued, the side load and bending moment would be way too much causing them to loosen very easily. Locktite and proper torque would be critical. Poor design maby?

Good point about the pully pic Hoop, I don't get it either, unless it was some crazy compound failure.

 

[R_W_B]

In my opinion, I seriously doubt it. To shear off 5 TIGHT (tight) bolts in one shot would take a whole lot more torque than these engines have. .. .. .. .. .

Looking at the pics I have to now agree with Hoops thoughts on the oblong holes indicating that the assembly was loose and torquing back and forth for quite some time. Keep in mind that all 5 bolts heads were found at the failure location so the swing arm did not knock them off one at a time and they would not loosen up at the same rate to knock them off in one shot, and further moor the heads are not damaged.
.... .. . .... ... . . I have to say if the money was coming out of my pocket, I would be all over finding the root cause.

So then it's honing in on the a defective rubber or compensator bowl, OR the bolts not being properly torqued (and/or re-used and/or no loctite) and coming loose, thereby causing the bowl and rubber failure and then the resulting bolt shearing?

This would be the first time I've heard of that scenario and I surmise it would be isolated to the IDS models. Since all the broken bolt scenarios I have heard of prior to this were from backing out and hitting the swing arm resulting in swing arm gouges etc. Luckily for all who were involved, I have yet to read of a case where the tire locked up and put the rider into extreme skill or death mode.