JXV Posted November 15, 2014 Share So I offered to replace some worn chainrings on a friend's 2011 Merida 96. It has FSA BB30 carbon cranks. These feature a captive self-extracting nut on the left hand side crank. I'm a Shimano guy so I watched all the youtube vids and downloaded the instructions direct from FSA website, then I tried it. Only it didn't self extract. They all say the nut goes initially loose then gets really tight when you unscrew it to extract it. It did exactly that, so I kept pulling ( normal allen key, not a long lever) and I sheared the extracting flange off the nut. So it is obviously seized on with corrosion or some such. Any tips for how to release this crank arm? If possible I will buy a replacement self-extracting nut ( or a new set of cranks) but whichever way it goes I still have to get the old ones off the bike. Link to comment Share on other sites More sharing options...
Guest DieBees Posted November 15, 2014 Share I had the same issue. Once the left crankarm is off, tap it lightly in the direction of the drive side, it should come loose. Otherwise, spray some Q20 there where the bolt came off and meet the bearing, it should have gotten stuck over time. Link to comment Share on other sites More sharing options...
Spoke101 Posted November 15, 2014 Share Pic's Link to comment Share on other sites More sharing options...
David Marshall Posted November 15, 2014 Share I've been there and done that. It is a stupid design so don't blame yourself. You can try an extracting tool (the tapered ones with a left hand thread). You may have to first drill a hole. The last one I got out - after stripping the tool thread, by fashioning a slot in what was left of the bolt with a Dremel and managed to get it out with a piece of tool steel flat bar and a shifter. It was a two man job. I now use a very long allen key that goes right through the bolt and an impact wrench. Link to comment Share on other sites More sharing options...
Skylark Posted November 15, 2014 Share Impact wrench is the sucker for that job, the impact blows help loosen the nut and break the locked up faces at the same time. Easy enough with one, often near impossible without. Link to comment Share on other sites More sharing options...
JXV Posted November 17, 2014 Share Thanks to all for the advice. See pics....the thick alu 'washer' is the extracting flange that has neatly sheared off the bolt. The two pieces should be one solid part. The bolt was tight but turned easily enough with a standard allen key. I suspect a previous mechie actually sheared it and made a plan on reassembly because what I also managed to do was burst/crack the retaining collar. This could not happen if it was me who sheared that flange cos the bolt would have just screwed out past the flange. Anyway LBS promised to get it off for me and has a spare self extracting bolt and collar for me so I can re assemble correctly. R250 for a lesson learned...not too bad I guess. Link to comment Share on other sites More sharing options...
Skylark Posted November 17, 2014 Share R250 is a very cheap lesson, nice of the lbs to sort it out Link to comment Share on other sites More sharing options...
JXV Posted November 17, 2014 Share So I got it back from the shop and all sorted. Looks very different now with the extracting bolt flush with the collar - and makes me realise that someone had previously botched it. Link to comment Share on other sites More sharing options...
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