Saturday, October 29, 2011

Stripped crank brought back to life

Sometimes when we get a challenging bike related issue at GF, we move our process to a super secret off-site location.  In this relaxed, shop away from the shop, we can relax, brainstorm and figure crap out.  Tonight's mission: repair a BMX crank where the pedal threads had been stripped out.  This steel crank also had a home repair attempt and was filled with some sort of JB Weld.  It was a mess, but these were expensive cranks and presented a challenge we were looking forward too.

Of course the right tools always help and we had a drill press, pedal inserts and a pedal tap.  So, first we started by drilling out the old pedal threads/hole to get a fresh start for taping new threads.  Super, super slow process going through this thick steel...and involved a drill bit sharpening in the middle.

Once drilled out, we had a nice clean interior surface for our tap.  Lots of cutting fluid and patience were key.
 

Now came the fun!!  Tapping in the new threads was rather easy and felt real good.

Once we removed the tap, our new threads looked amazing!  The sight of some freshly cut threads is always a welcome sight.

We took a 9/16 pedal, greased it's threads and then threaded a new pedal insert onto it.  It was easy and doable by hand.  Once the insert was on the pedal, we put some loctite on our new threads and installed our pedal with insert.  It threaded in like butter on those new threads.

We let the loctite sit over night to cure, removed our pedal and the crank was back in service.  A big thanks to Sierra Nevada, Fast Eddie and Annie for a successful evening of fun and bikes.

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