Coming Uncranked

I recently noted a bit of extra play on my left pedal.  Before setting out on Tuesday morning commute I investigated the drive train and found the problem.  Here is view of the left crank from one of my original fittings:

Here is the left crank as I found it on Tuesday morning.





The exposed splines and threads were the first hint something was wrong.  It looked secure enough so I tightened down the clamp bolts and set out.  About five miles in the crank fell off completely clinking onto the greenway pavement.

There are two things wrong with this picture.  First, the crank came loose again.  Clearly something wrong.  Second, the pedal and crank should have stayed attached to the cleat on my cycling shoe. A quick inspection:





The two metal studs about half way down on the left and right used to have completely round caps.  Looks like I successfully wore out my first pair of cycling cleats.  This only took ~11 years.  I bought these Speedplay Frogs during my first full year of cycling in NC.  They've cycled in Georgia, Alabama, North Carolina, Maine, and maybe Florida.  Thanks for the good times trusty shoes and pedals.  Time to move on.

I stopped trailside and reattached the left crank.  The worst thing about this was the cold quick onset of cold.  When temps are in the low 30s keeping moving keeps warm.  There isn't much movement in turning bolts.  Cold temps and high heart rate are killers for manual dexterity.

There was nothing to do about the cleat so I rode on.  The crank came off again while riding an errand during my evening commute.  This time it was getting dark so I tightened it down extra snug and made for home.

I am losing count of all the lessons from this experience.  I came uncranked but stayed unfazed.   In telling people this story several turned pale with concern. I appreciate their concern, really nice to know they care. In their view bike commuting is scary enough; adding a mechanical was incomprehensible. To me it was mundane and possibly an annoyance at most.

Reattaching the crank was a simple mechanical task.  I had it replaced and rolling again without missing a beat of conversation with Mom on the phone.  She didn't want to get off the phone while I was still stranded on the side of the road.  By the time she made the comment I was almost a mile down the road.  Thanks Mom for keeping me company.


Allowing the cleat and crank to unknowingly get into that condition is another lesson.  I need to be more diligent in maintenance.  The crank is missing a part that the bike shop had to order that will now keep me off the bike for a week.  The lost training time is a big penalty.  This is a clear price to pay for ignoring maintenance.  At the same time it is all good practice.  Kenny assures me this mechanical is rare.  Rare or not I will be more attentive to loose parts going forward.  I'm also getting an extra spare for the pedal should this happen again. Kenny patiently entertained my questions about securing other bolts on the bike.  After a few loose nuts (other than the rider) on my tricross I removed all the bolts and reassmbled with removable Loctite.  Kenny assures me this is not necessary on the Moots as they took care of this during assembly.  This is an anomaly with the bottom bracket and crank.  I love these guys at Bicycle Chain Chapel Hill.

I dropped off the Moots and picked up my Tricross from a fresh tune up so I was back in an old familiar saddle on Wednesday.

Pulling it all together:

• Attend to critical dependencies.  An ounce of prevention is worth a pound of cure.  Tightening a loose bolt is much easier than finding or replacing one that falls out. Loctite keeps bolts from coming lose minimizing maintenance. Minimal maintenance still does not mean no maintenance especially under "extreme conditions".
• When things do come loose then use what you've got to get moving again and get to a place where you can take care of it permanently.
• Pictures and documentation of the original design and "known good state" are helpful in diagnosis.
• If a piece proves prone to weakness or failure then shore it up, know how to work on it, or plan to replace it.

All of this is completely tailored to the situation.  The Moots already has over 350 miles on it.  Few bicycles ever see that mileage, let alone in less than a month.  Few bikes face the mileage I plan for this one.  It's got a long way to go to reach the ~4k miles I put on the Tricross last year.

And speaking of the Tricross - I felt screaming fast on narrow cross tires after so much riding on 29er knobbies. Cranking along relatively easily in the big ring is quite a boost of confidence. 11.6 MPH with the knobbies vs. 15.6 MPH without.