Friday, March 8, 2024

Black Oval chainring, Crank Breaker?

    So, eight years ago, when my 3x9 was wearing out and 1 bys were becoming all the rage, I opted for the Shimano XT 42-11 cassette and needing a no drop chainring I got a 32t from Black Oval. 

See hear for the install:

Yes, I kept the package for Eight years!

My First ride on this set up was May 24th, 2016.  And While I did not ride much after May 2017 Strava says I logged 212 rides on that set up since.  I am not prepared to do the data mining yet for the miles and elevation gain, LOL!  Needless to say, it was a lot. I did replace the chain in October of 2019, when I got back on the horse to ready myself for some friends that were visiting in February.

So, as I was JRA anticipating getting my single speed together going up a short steepish climb in the 32/21 I believe and bang, I thought I broke the chain, not so lucky, while the chain did get twisted a bit, I looked down to see a mangled mess of twisted chainring.  Thinking to myself that’s odd, but I have more at home.  But before I could contemplate the walk out to the road, I realized a much bigger shock, three of the ears that held the chainring on the crank had completely snapped off!!!! and the 4th was ripped open?  This is an XT crankset and yes, I have put umpteen miles on it and I tipped the scale at 240+ pounds and my legs were getting strong after a few months on the bike (After 4 years off) and lifting many kegs at work, but jumping Jehoshaphat!  Me and My buddy just stood there not quite comprehending what had happened.  My friend, who worked in a bike shop for quite some time said, "That's a new one" and between us we thought we had seen broken or broken ourselves, everything on a bike.  I also worked at a bike shop for several years and one of my friends wife use to call me "everything is broken Man"  

But I digress.  So was it metal fatigue, was I too fat.  While my friend rode to get the car and I walked to the nearest trail head, (we were halfway through a 14-mile ride) I had time to ponder and wonder if the Black Oval chainring, which was light weight (maybe too light) and the material around the bold holes got nowhere near the lands on the crank was the culprit.  All the bolts were still tight in the threaded chainring holding on the three ears from the crank, suggesting that the chainring fold/twisted under the load and twisted off the ears of the crank.

There was a silver lining though, we thrashed that evening and converted My Lynskey with a Black Sheep fork, back to its single best destiny... a 

Single Speed

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