Okay, I know this has been discussed a number of times but this is something I have never experienced before so it's a completely new problem to me.
We were going up a short but fairly steep section of road this past weekend on our tandem. The wheelset is a circa 2006 Rolf Prima Vigor. The bike is a recently purchased off craigslist Trek T1000. The 9speed cassette is almost new. Chain and chainrings came with the bike, but appear pretty good.
We had ridden up some pretty steep hills with this bike and set up before with never a hint of a problem
We were leaning heavy on the pedals at this particularly steep section and all of a sudden the pedals slipped with a sort of ratcheting sound. Naturally, locked into the pedals, it was a heart stopping moment as we nearly teetered over!
Having never experienced this before I immediately thought one of the chains had slipped over some sprocket or chainring teeth.
Once off the bike on the side of the road, I began to think it wasn't a slipping chain, but a slipping freehub.
We continued up the hill, under more moderate pedal load and experienced no more slipping on the way home.
Once home, I took the freehub apart. I noticed a tiny amount of wear on the outer edge of the ratchet ring (whatever it's called) but pawls seemed okay and sprung back and forth okay.
To me, never having ever taken apart freehub before, it all looked pretty good. But what do I know? Any insight? (Or if you prefer, incite.)...Oh, if I need a new freehub, can some one make a recommendation. Currently running 9speed Shimano and would stay with that.
Photos to follow:
