What is the safe minimum number of threads that must engage, track rod end into ball joint. I'm using sierra rack and having just fitted Quaiffe quick rack internals I'm only getting about 5 threads in each end. This seems a bit marginal. Would be a pain to have to shorten the rods, re thread the ends and fit extensions.

I would say the length of thread should be at least two times the diameter..

Dan

If I can rock it on the thread I'd consider it not enough, I would have thought the maximum you can screw it in as about 12 turns anyway?

should be at least 1.5 times the diameter

Yep having looked at it, 1.5 is probably o.k 2 would be over kill.

Dan