Middleburn rs7 lock ring thread help

[ishaw]

I bought a set of rs7s a good while ago and discovered previous owner had been a bit ham fisted with the lock ring for the spider.

Upon removal I found that the very outer/top thread had been damaged so I can't get a new lock ring back on. The rest of the thread is fine.

So I'm after some advice/help on what options I have to sort the thread out so I can refit the lock ring and secure the spider.

I'll post some pics in a bit, but basically in words, the thread that the lock ring bites on has a dent in it, preventing it from fitting.

I'd imagine a die would sort it, but that's not a tool I own, so wondering if anyone has any ideas on what's possible. Using the new lock ring will probably ruin it

Cheers

 

[Blacktopdisciple]

I'd suggest running a die down it. Could you ask Middleburn (now owned by BETD) what the thread pitch and diameter is and then see how much a die would cost?

 

[hamster]

Running a knife edge down the thread may be enough to clean it up and get the ring to bite and start.

 

[old_coyote_pedaller]

Running a knife edge down the thread may be enough to clean it up and get the ring to bite and start.

Was going to suggest something similar. Back in days of yore when the cars I drove were older than me, Minis, Imps, if the thread on a bolt got a bit chewed at end I'd use a junior hacksaw blade to clean it up. Usually it was bigger bolts on suspension so the blade would fit in threads, starting at the last good thread and gradually reform a thread so nut could start on bolt.
As suggested, using a sharp knife on the aluminium of cranks would be a better option than a brutal hachsaw blade.
Using a die wouldn't be ideal as you might not be able to start it exactly where original thread was as if you can't get the lock-ring to start the die might be the same. Chasing it back from last good thread with the knife more likely to work.

 

[ishaw]

Thanks for the advice. I sorted it as suggested, using a sharp edge to nudge the thread back into position and it's all back together.

One thing I noticed with the various Middleburn cranks I have is that some have the lock ring round one way, some the other, any reason for this?