Auto-shifting driving me nuts!!!
 

I do friction shifting. Auto-shifting can hurt when using lotsa pressure on pedals. Especially while standing.

Ultegra front and rear derailers.
10-speed cassette. Compact up front.
Bar-end shifters.

In 2-6 cogs, auto shifts. Hard to predict. Happens a few times per commute.
Happens more often going uphill. Sometimes I can hear a tick,tick,tick while pedalling before is shifts itself. Sometimes when it shifts itself the cranks go a half turn.

I, and the LBS, have tightened up the shifter, and the cable, which has helped a little.

Any ideas?

Would going o a 7 or 8-speed cassette help, due to wider spacing of the cogs? My dropouts are 135mm wide.
I am not a racer, and don't need all 10 cogs in back.

That tick-tick-tick means that you're not aligned perfectly with the gear in back. Try trimming your shifts -- reverse the movement of the lever slightly after making an upshift.

10-speed cassettes are very closed spaced and pretty intolerant of "near miss" shifting so a wider spaced cassette should help. 8-speed would be best as it has the same spacing as 7-speed but offers one more cog.

The problem could be the shift levers still aren't tight enough and slip after a while but it could also be frame flex. You mention it usually occurs while under a lot of pedaling pressure particularly while standing which does indicate the rear triangle is flexing under the high chain tension. The 8-speed cassette will allow for more alignment slop but a stiffer frame is the only sure cure.

Before the hyperglide tooth reshaping for the index shifting to work, early,
the full height freewheel tooth may have shifted later,
and required trimming after the shift, but the chain tended to stay on the cog,
until forced to change, by the rider.

As others have mentioned, auto-shifting like yours is a a trim problem. On index systems the trim is built into the shifters, without index it's up to the user. You're using a very narrow cassette which has shift gates which make it more prone to shifting than plain sprockets would be.

Start by checking that all housings run cleanly and squarely to the cable stops. The least amount of housing flex at a stop, levers the ferule against it's rim pulling on the inner wire and changing trim. It's possible that flex, bouncing or rocking as you claim is moving the housings enough to throw the trim off.
There may be another remedy. Using a floating pulley for the jockey wheel as in Shimano index derailleurs will allow the pulley to stay in trim when there are slight movements of the RD (This is why Shimano uses it for index in the first place). It will take a bit of getting used to but once you do, it might be enough to solve the auto shift problem. No guaranty, but it's worth a shot since a pulley is much less expensive than a new frame.

Note- Replace both pulleys with a matched set floating upper/non-floating lower, since there might be a difference in overall width between the new one and our old ones. You might also need longer cage screws, so check that there's enough thread engagement and buy longer screws if needed.

Do the shifters loosen up over time and need retightening ? Maybe a little thread lock would help. (not the permanent type)

Only other factor that might be causing trouble that I can think of is this:

What are these two black washers for?The shifters have these two washers, with a tab that sticks out perpendicular to the washer face. I think it is not meant to go with the bar end pod, but the bike came this way. These are DT shifter mounted on bar end pods. Maybe trying it without the washers may help? I don't know what they are for.

http://i398.photobucket.com/albums/p...m/f8d14a5c.jpg

The little tab fits into the arced recess in the lever to limit the range of motion. It's simply an overtravel stop and shouldn't affect friction either way.

You need to determine whether you have a lever slip problem, or a trim problem. Not knowing exactly what's happening makes fixing it impossible.

Early Campagnolo downtube friction shifters were notorious for doing just that and causing ghost shifting. You had to tighten the D-ring every couple of rides. Simplex sold a lot of their "Retrofriction" shifters because of this.

True, but it was mainly a problem with the B and C line shifters that used an outer plate with a tab that went down to the back plate. The long tab had some give and the outer plate walked back and forth loosening the wingnut. The A line Record shifters used a side flatted central shaft (still used on lever bosses, like the one here), and mating outer plate which was very reliable.

Someone mentioned inspecting the cables and housings for kinks or excess length. I'd take this a step further. I think you're going to have to replace your derailleur cable and housing with a brand that offers the least compression. Frame flex or cable tension problems are the source of most auto shifts. If you can't reduce frame flex then you're going to have to reduce cable stretch and the easiest way to do that is by encasing the cables in a housing that resists compression.

The bar end shifters are making matters worse (than down tube shifters, for example) because you're running considerably more housing and you're running it along the handlebars which are typically flexible to begin with.

Good luck.

Check your derailleur hanger for proper alignment. If it's bent, it can cause all kinds of shifting problems.

If your frame has horizontal dropouts, make sure your wheel is installed straight and your quick release is locked down tight. The drive side can pull forward during hard pedaling.

Check you chain. Make sure it's a 10-speed chain (narrower than an 8- or 9-speed). Check for bent links and protruding pins.

tcpasley

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