lungimsam

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.