Hey everbody,
I’ve been working on this old Trek 800 and gave it a bit of an upgrade. I installed a 7-speed Shimano Tourney setup, but I just can’t seem to get it tuned properly. I can set the high and low limits fine, so the chain sits correctly on the smallest and largest cogs. But I’m struggling with the cable tension — either the chain won’t shift smoothly down (especially from the second smallest cog), or it won’t climb up properly.
I’m starting to wonder if I’m missing a derailleur hanger adapter or something similar since I mounted the derailleur directly to the frame. Does anyone know if that could be the issue?
This whole shifting problem is driving me crazy, and I’m thinking about switching to a CUES 1×11 setup. Before I spend the money though, I’d like to know if that would even work with this frame — or if the lack of a derailleur hanger makes it impossible. Thanks in advance for any advice!
by kailiermann
5 Comments
Did you change the cable?
Have you checked B tension?
Have you rechecked the cable tension after a bit of use? Often it will loosen a bit as housing ferrules get seated farther, etc.
Check to make sure your derailleur hanger is straight. Even brand new hangers can come out of alignment.
Check for any kinks or bends in the cables or housing.
Run thin oil through the shift housing. I use TriFlo or DriSlide.
Triple check the shifter is made for the correct number of gears.
Check the b-limit. Many Tourney derailleurs don’t really have much b-limit adjustment but if there is a b-limit screw, try adjusting that. The closer the upper pulley is to the cassette/freewheel, the faster and more accurate the shifting is, but if you get it too close, it’ll grind when you shift and the derailleur can contact the cogs.
Make certain the derailleur is mounted properly.
Start on the smallest cog, shift up 1 gear and adjust tension so that shifts properly. Then go 1 more gear up, repeat. Once you hit the biggest cog, downshift one gear and see if it shifts & adjust tension to make that shift properly.
My guess, with knowing very little about your setup, is a bent derailleur hanger or excess friction in the cables/housing.
25 year mechanic here. Lots of shifting issues are cable related. Is the housing original? On some older bikes you will find compression housing (brake housing) instead of compressionless housing (shift housing) and it does not hold position as well. Also, not all cables are equal. Slick cables move a lot better and don’t get hung up in the housing like basic galvanized cables do, especially on the rear.
Second, what shifter are you using? Unlikely to be the issue but there are some Sram shifters that use a different pull ratio.
Also, how old is the chain? I see it is shimano, but it could be worn out
New Tourney derailleurs work well when all this is taken into consideration. The challenge with them is that their pivots wear out a little faster and they can get ‘jiggly’ and don’t hold position as well over time.