Broken Skid plate welds......

[FastDoc]

Having recently been back in San Diego I can see how nerve wracking a breakdown would be. Heck even in an air conditioned cage SoCal traffic still stresses me out.

[RX3James]

Originally Posted by pyoungbl

OK, your azz. I do welding. From the photos the weld is still 100% intact. There was decent penetration. The part did not "rust off". Just look at the edges of the weld where the metal is broken off. That's a sharp edge. The sharp edge is due to a crack and the rust you see is just normal surface rust that you get from bare metal exposed to the atmosphere. The rust is also fairly recent, otherwise it would be crusted over and expanded. No, this is a crack that was either caused by impact or vibration. I'm now of the opinion that vibration is the culprit since others have had exactly the same problem.

This seems like a very reasonable answer. I'm not a mechanic or welder so I can only go off what my inexperienced eyes see. That's why I posted here. This community has been extremely helpful getting me through almost all the maintenance I've done on the bike. So I knew one of you Zong experts would more than likely have a better answer than me..

[2LZ]

Originally Posted by RX3James

Battery died at around 200 miles( I bought a new one with a two year warranty ), front rotor was warped causing pulsating front brakes (replaced under warranty ), had a chain issue causing it to scream really loud even with proper tension and lube (bought upgraded chain ), right side mirror broke off (replaced under warranty ), The engine likes to die at random times, like it just completely shuts off and wont restart until I come to a full stop and shift into neutral and restart (has happened in heavy San Diego traffic twice now which was pretty nerve racking ) the engine temp runs between 4 and 5 bars constantly (but the fans do come on and I haven't over heated so I'm not too worried about that... but it does add a lot of heat in my ATGATT in Southern CA stop and go city driving)

Well heck, it sounds like you have all the "standard fair" RX3 issues already fixed! I've read in a bunch of places here that the dying may be caused by loose or dirty battery cables. When did you check them last??

[RX3James]

Originally Posted by 2LZ

Well heck, it sounds like you have all the "standard fair" RX3 issues already fixed! I've read in a bunch of places here that the dying may be caused by loose or dirty battery cables. When did you check them last??

I checked them the other day when I changed the oil and oiled the air filter. They were snug and looked clean. But...
Come to think of it I never had this issue until after I replaced the OEM battery so maybe I should take a better look.... my 2nd thought was something that Spud had mentioned to me a few months ago. He said my valves might be too tight which could be causing the dying issue. I think I'm gonna check them on sunday and take them all the way out to 0.8mm and see if that makes any difference.

[2LZ]

Originally Posted by RX3James

I checked them the other day when I changed the oil and oiled the air filter. They were snug and looked clean. But...
Come to think of it I never had this issue until after I replaced the OEM battery so maybe I should take a better look.... my 2nd thought was something that Spud had mentioned to me a few months ago. He said my valves might be too tight which could be causing the dying issue. I think I'm gonna check them on sunday and take them all the way out to 0.8mm and see if that makes any difference.

That could do it also. I'm not sure if you followed my thread or not but my brother and I each bought a pair of RX3's, used(?), from a nice gentleman in Oregon. These were supposed to be the first batch not prepped by CSC but supposedly the crates were send to the customer to assemble.

My bike had about 80 miles on it (my brothers had 17) and after I put 100 miles on it, I wanted to check the valves, just in case, since they hadn't been set by CSC. All but one were at .08MM. Just one was a little tight. I'll be setting mine at .08MM from here on out.

It really does sound like you have all the normal bugs worked out. I hope you decide to keep it. I really enjoy mine. It's a fun bike to ride..and when the rotor warps, I'll replace it, etc...etc... At least I won't be surprised! ;-)

[Jay In Milpitas]

From what I'm seeing on both bikes, the failure is indeed vibration related.

I don't really like the forward mount having two parallel arms instead of triangulation or a transverse mount. If the two bolts at the rear of the skid plate don't securely clamp that portion, the front is allowed to vibrate even more.

Cyclic vibration fatigues the metal and breaks the grain boundaries at the edge that is most under stress (tiny crack). Once the crack is started, progression accelerates which allows the plate to swing further in vibration, in turn bending the metal more and more.

The dusty/powdery looking rust is the result of the edges rubbing back and forth against each other. This is something to keep in mind every time you work on any machine, a streak of reddish brown is a sign of iron oxidation and the cause should be investigated as soon as possible. It may be something as simple as a motor mount plate needing the bolts tightened. With aluminum the clue is white powdery residue.

Just my 2 cents worth, so feel free to ignore it.

Jay Littleton,
Former Nondestructive Inspection Technician, USAF (ret'd)

[pete]

weld them back on...
frames ridged skid plate is vibrating
so something had to give and it found
the weckest point...

put thick rubber between the plate and bracket...



..

[pyoungbl]

Originally Posted by Jay In Milpitas

I don't really like the forward mount having two parallel arms instead of triangulation or a transverse mount. If the two bolts at the rear of the skid plate don't securely clamp that portion, the front is allowed to vibrate even more.

Cyclic vibration fatigues the metal and breaks the grain boundaries at the edge that is most under stress (tiny crack). Once the crack is started, progression accelerates which allows the plate to swing further in vibration, in turn bending the metal more and more.

Jay hit the nail on the head. This is a design issue. With time I'd expect the same failure on most RX3s. You can either remove the OEM plate and ride without one or install the CSC optional plate. If you do not plan to ride off road the plate is window dressing. Heck, some 'adventure bikes' come with a plastic bash plate.

[2LZ]

I also like Pete's idea of putting a rubber grommet between the plate and bracket. I'll do that and see how it goes. Even my old X-Moto has rubber mounts for the skid plate.

[CSaddict]

Upgrade to the aluminum skid?

[SpudRider]

Originally Posted by pyoungbl

OK, your azz. I do welding. From the photos the weld is still 100% intact. There was decent penetration. The part did not "rust off". Just look at the edges of the weld where the metal is broken off. That's a sharp edge. The sharp edge is due to a crack and the rust you see is just normal surface rust that you get from bare metal exposed to the atmosphere. The rust is also fairly recent, otherwise it would be crusted over and expanded. No, this is a crack that was either caused by impact or vibration. I'm now of the opinion that vibration is the culprit since others have had exactly the same problem.

Originally Posted by FastDoc

'I'm now of the opinion that vibration is the culprit since others have had exactly the same problem. '

I agree. The part failed from a crack. The crack was probably caused by vibration. The exposed unprotected steel then rusted.

I think this is the sequence of events, and that rust is a consequence and not the cause.

With that said, it's not a mark of quality per se, but not a reason to suspect the other welds on the frame.

X3; I agree on all points.

This bracket recently failed on my RX3, which has 18,000 miles on the odometer. I followed the example of Woodlandsprite, and re-attached the bracket with two hose clamps.

I am not worried about any of the other welds on the motorcycle. I agree this bracket was not adequately designed to resist vibration, and rubber cushions might mitigate the problem. However, I think the two hose clamps will permanently fix the problem. I agree it is probably wise for all RX3 owners to install the two hose clamps before the fracture occurs.

[madsocial]

For anyone riding off-road the Aluminum skid plate is the better option. I don't know anyone traveling the world by motorcycle without an Aluminum plate. Even the motocross guys have aluminum skid pates for their dirt tracks.