Monday, 12 May 2014

Shimano FC 6700 crank fail

But perhaps not the kind you'd expect.  

Whilst trundling to work with Lawrence last week i turned onto the pedestrian overpass at the convergence of Victoria Rd and the ANZAC bridge when something went clunk.  Not just the grinding of gears.  Both feet found themselves in the down position.  Bicycles don't work that way.  This was serious.  Even though the Wombat has now carried me for 42K kms, never expected I'd be adding cranks to the list of things I’ve replaced on it.  Somewhere, hidden between the outboard bottom bracket bearings, the crank axle sheared.  Never seen this before.  Nor had the bike mechanic who just happened by and asked if he could help.  The incident did, however, facilitate a very pleasant stroll over the Darling Harbour walkway, something I've not done in daylight since I don't know when (thanks for the loan of the shoes, Lawrence).

Strangely enough, had I listened to Karma (or believed in such bunkum) I might have expected it.  Only the weekend prior I was in the St Albans beer garden imbibing the local drop and swapping Convict stories.  Just 30 meters away the post-podium lucky draw prizes were being distributed.  Name after name was being drawn, then discarded when the owner didn't pipe up.   Suddenly I hear my name called and return to the table with, you guessed it, a brand spankers crank set; FSA K-light hollow carbon cranks, albeit 175 mm (a fraction long) and sporting mtb tooth configuration (40/27).  Quite happy with XTR really, and in any case not really designed for the road.

The scary thing is, only days before the fail I'd been doing the 3 valley loop with Chris.  We were both on the limit hanging on to a couple of A-graders along the Arcadia road.  Had the fail occurred during maximum effort I’m not sure I would have kept things upright.  A little disconcerting to say the least and makes me wonder what might be next?  Hence, time to accelerate the look for something new.

 FC 6600 (shiny, LHS) has a much thicker axle wall than the 6700 series which replaced it.  Hence, 6600 should do me for the time being.


  1. Welcome to the BBB club! Bottom bracket busters; admittedly, mine was an all-Ti axle failure - not *that* uncommon back in the day er lad - but impressive nonetheless. As for your effort, I should mention the words 'abuse' and 'lack of regular maintenance', or even make a comparison with Italian craftsmanship. Lucky it didn't come out of the BB shell and remain attached to your shoe, or break in some place less benign than the bridge. A lucky escape, Langles.

  2. Point taken ("lack of regular maintenance"), although i'm not sure whether maintenance would have helped me - apart from picking up signs of the fracture early. I replaced the bottom bracket outboards only 6 months ago and didn't notice anything odd.