Alberta1980

Just bought a townie with a 7 speed revoshift. It will somewhat downshift to 6th with a bit of effort and sometimes go down to 5th but won't go past that. If I release the cable from the derailleur the shifter twists fine, even if I add resistance. When I pull the cable for the derailleur close to the BB the derailleur will shift gears. However when everything is connected it just won't shift. I replaced the shifter cable as well and the old cable looked great from what I could tell. I have a spare revoshifter that I will try tomorrow but was wondering if anyone has any suggestions. Note that the housing is one long solid piece that is internal

JoeTBM 

Your two statements are conflicting. I suspect that you actual have two pieces of housing, one internal to the frame and a short piece near the rear DER. If the housing ends are not absolutely straight (bent at ferrules) this will add to the friction as well as any dirt/corrosion in the housing.
You do not say but I suspect this is a used bike, I would change the housing and cable. With cable not yet connected tot he DER rotate your pedals until the chain is on the smallest cog. Make sure your shifter is ion "7" and chain is on the smallest gear before attaching the cable. Look at this video before making any adjustments https://www.parktool.com/en-us/blog/...eur-adjustment

soyabean

Do shift cables wrap once around inside a revoshift, or was that sram?

HillRider

Try shifting the rear derailleur by hand with the cable disconnected and turning the crank by hand. Does it go all the way to the lowest gear? If not the low limit screw may be misadjusted.