Crank Bearing Seat Imperfections

[bosshasr]

Are these little rivers on my large crank bearing seat something I should be concerned about?

 

[TwoManyXS1Bs]

That's the upper seat area of the primary drive ball bearing.
Some bikes have a history of gear grinding alongside that area, from a mis-spaced clutch primary gear, or broken parts getting trapped behind it.

Look for scratch marks where the clutch gear passes by there.
If the lines are just blemishes, with no hidden cracks, it's okay...

 

[bosshasr]

I checked for scratches from the clutch primary and didn't see any. The gear itself also seems to have no damage.

I can feel that the lines are there but I don't see any actual cracks hiding in them or near them. They also seem to only be on this half of the case.

 

[TwoManyXS1Bs]

They're probably just blemishes, then. Nothing to worry about.
To know for sure, you could have a dye penetrant test done...

 

[bosshasr]

Thanks TwoMany. I'll run the risk and see what happens. Curious how those patterns developed in the first place. Kinda looks like I had aluminum termites.