Cheap downtube shifter won't tighten
A friend recently purchased a cheap BikesDirect road bike with cheap down tube shifters. They are indexed for 8spd cassette but cannot be tightened so as to hold the cable from slipping to a smaller cog. I thought that possibly there was too much paint on the boss or the threaded insert had flashing keeping it from being tightened down but clearing those issues brought minor improvements. I didn't want to overtighten it as the frame is aluminum and the boss appears to be as well. It tightens on with a small 3mm Allen screw. Anyone familiar with a BikesDirect Dawes Lightning DT with Sunrace shifters?