Bad WTF Crack

[Roostmaster]

Hey guys have any of you seen an AF frame crack at the head set / stearing stem??
If so why?
My tripple clamps where tight and she hadnt had any big crashs but she does have a worked bigpower motor which Ive run geared up for speed -15 / 38- maybe the frame flex stess is the cause?
The bike shops I showed said they hadnt seen a Honda alloy chassis crack like that before!

[gregrobo]

never seen one like that before right down the mould join

[zorak-2]

thats weird for it crack there.May be you can V it out real good and clamp it and take it to a real good welder and repair it?

[dubious01]

Casting flaw would be my guess.
I have a welder who I would trust with diagnosis for repair / if repairable safely.

[dannygraves]

I've never seen that before, I'm going with the others on here with casting flaw unless your head bearings were way too tight, they should be just snug and seated, but not tight, like car wheel bearings, you crank it tight, then back off aroudn a 1/4 turan and back and forth to feel where it "seats"

[asteroid500]

I think it may of been repaired like this.

Step #1..find & locate crack, we used a chemical crack tester.


Step #2..drill a small hole strait threw the headstem to prevent further travel of the stress fracture.


Step#3..V or groove out the fracture to a debth were the Tig weld can penertrate deeply & build up the material required.




Step #4..We ran a tripple fillet weld on this frame as it is a mate of mine's, center, left, then right.


End result is a frame with its full structual integrity. ;D
Dont this frame look like the hammer in pink floydes, The Wall.....when it's been grooved out.
All this work was carryed out at Wereabout Engineering by Dave the Tig master and crazy Carl, in Darwin Australia. 8-)

Hey Scotty, were do i send my crank for balancing?

[gregrobo]

asteroid when that crack was chased did they find any sand/imperfections

[asteroid500]

no,
the crack wasn't found strait away and had been riden hard so it was full off grit, requiring an acid wash to make sure no alloy spat on the mig

[gregrobo]

ok the welder would have knew what i ment by my question sand/imperfections/airpockets in the casting

[asteroid500]

Yeh, knew what you were talking about , a clean crack stait down the forge line

[blackz34]

The frame I got from ebay was crackd just like this (CRF450 2006). I already had the frame sitting in the garage for months waiting for completion when I discovered the crack and already left a good feedback to the seller so I just had it welded like asteroid did. The difference beeing that we left the bearing race in place to avoid any machining. So far so good.

[gregrobo]

once the swingarm pivot bolt is in place it has to be aligned with the swing arm providing the right bolt is used