Anyone else snap a center suspension pivot arm?

[Alatalo]

I cracked a center swingarm on my -08 RTX 40th, but not in the place you are talking about. My left side tube (connecting the upper tube and the left side rail) started to show a crack straight across the tube at the end of the season (approximately 5000 kilometers).

Just to clarify, this happened with a non-OEM center shock absorber with a very short and non-restrictive passage between the shock absorber body and the compression valve.

Change the shock hose! Call Leein at HyGear, he will tell all about that shock.

The shock absorber hose is obviously restrictive, but based on the input from the guy that started the thread, is this really his main problem...?
The guy is reporting about frequent bottoming out followed by a broken swingarm. This would indicate that insufficient compression damping caused frequent bottoming out and thereby frequent load peaks that eventually broke the swingarm.
A too restrictive shock absorber hose, on the other hand, means an over-compensated shock absorber pressure balance which is exactly the same scenario as running a very strong compression valve. Moreover, the flow characteristics of a long, uniform hose would create a pressure build-up (and thereby a compression damping force build-up) that depends on the compression velocity squared, at least. All of this indicates that the rider would for sure not feel the shock absorber to be soft or bottoming out. If anything, he would feel the shock absorber to be very hard, harsh and un-compliant. Unless the shock absorber was blown in the first place, of course...?

 

[stopdropanroll]

Could the shock feel like its bottoming out when in reality the resricted flow has the shock bound up creating a shorted shock stroke? If that was the case it would put more pressure on the pivot arm, not sure if that makes sence to you. You seem to know your stuff when it comes to suspension.

 

[**sj**]

point is...09 rtx....big bump sled....obvilously maintained if he had the shock revalved last year...Id be on the phone with yamaha customer serveice ...assuming you started at the dealer and were out of warranty...and be pitching a beotch...