Bike is shifting on its own Ever since I got my bike (Surly Long Haul Trucker), it has been prone to shifting on its own.  This is almost guaranteed to happen when I stand up on the pedals, and happens regularly when sitting as well.  I have the feeling that this is a dangerous condition.

It seems from reading about the problem that it is due to the cable catching somewhere and creating a clutch effect.  (read about it here)
There does not seem to be a way to adjust the friction of the shift lever.
I've tried:


greasing the cable guide under the bottom bracket (no effect)
backing off the tension of the cable with the tension knob on the cable casing (no effect)


Can anyone relate how they overcame this?  My next step is to further loosen the cable by adjusting the connection to the derailleur?
Neil is right, most all &quot;auto shifting&quot; or &quot;ghost shifting&quot; is the result of cable-tension problems.
If the cable is a bit loose, the derailleur will try to shift &quot;up&quot; to a smaller cog.  If too tight, it will try to catch the next larger cog.
Cables stretch, especially after a short period where the new cables stretch to the point they're stable.  after that, they should be good for a long time.
Try this.
Shift to the highest (smallest) cog and try to pull the derailleur cable away from the frame.  If there's a lot of slack, it's too loose.  If it feels very tight....
With either condition, make sure the shifter is in the highest position, and loosen the cable at the derailleur and then pull it snug.  Re-tighten the securing bolt and run it through the gears; it should be very close.
Ideally, the chain should jump smartly to each cog both up and down, and seat solidly on the cog.
If it's just a bit off, you can play with the barrel adjuster either at the shifter or at the derailleur.
Another cause of such problems is a bent rear derailleur &quot;hanger&quot;, the part that the derailleur attaches to.
Some of these are very soft aluminum and can be easily bent.
Make sure the derailleur cage is exactly parallel to the cogs and the hanger is not visibly bent.