trextodd

Just picked up an old Schwinn world tourist 5 speed, and can't figure out how to adjust the rear derailleur?
I've watched a few videos on youtube, but not sure I fully understand what to do?

The problem with it, it wants to stay in a high gear only. I can manually shove the index shifter to the lowest gear selection & hold it there with my thumb, but once released it shifts back up to one of the highest gear cogs.?

Speaking of this old index shifter, I've had several new mountain bikes & road bikes with new rapid fire shifting, etc... but not even sure how this old Shimano index shifter was intended to work? It seems that it is one directional only? Or perhaps that is because it not operating correctly now, obviously?
I can tell that downshifting is pushing your thumb away, but then the lever returns back to the forward (towards you) position after every downshift.. so how are upshifts handled with this old style index shifter?

Thanx in advance for any help / input!

Todd

FBinNY 

A 5 speed bike is almost assuredly not index shifting. So you have friction shifters and the resistance to the RDs return spring comes not form discrete clicks, but from friction via clutch plates. The lever likely has a screw or wingnut at the center. This adjusts the pressure on the clutch plates and you want to set it tight enough to hold against the spring, but not so tight that it's hard to shift (personal preference here).

If you cannot adjust via the screw, there's a good chance that some of the clutch plates are missing, or simply dislodged. If so, you need to disassemble the lever and see if you can sort it out.

Homebrew01

Note the wing nut (sticking out on the left shifter). As FB mentioned that may just need a simple tightening. Some shifters have a standard Philips screw instead of a wingnut.

trextodd

Thanx for the response.
I've attached a couple pics (hopefully worked? ) of the shifter and rear derailleur. It's definitely not the old style typical road bike shifters as in the picture you sent. Take a look at my pictures.

trextodd

Hi there,

I'm not sure if I responded to you or the first person / response on this thread? Sorry, new to this forum and how the threads work.. anyways, can you see the reply I posted and pics please?
Thanx!
Todd

oldskoolwrench

OK...

In the second photo, see the Phillips head screw on top of the shifter, with the D shaped ring? That is the tension adjustment for the shift lever. Take a screwdriver and tighten the screw slightly. Push the shift lever away from you, like you were making a shift to a larger rear cog. Does it want to snap back as before? If so, tighten the screw a little more until the shifter stays in the position you want it to. Don't tighten the screw too much.

Also, look at the second photo again... see where the cable goes into the white plastic cover of the shift lever? Notice the slight break in the outer cable (the grey part)? You might want to unfasten the Cable from the derailleur, remove the inner wire, and trim that section of outer cable.

trextodd

Awesome, it worked!
As far as adjusting the high/ low on the derailleur end, I watched a video on youtube, but wasn't sure I fully understood it?
Do you have to detach (loosen the cable set screw) prior to adjusting on the smallest and largest gear / alignment with derailleur?
Then I wasn't understanding the adjustment of the threaded barrel on the cable end termination, after it was all hooked back up? What exactly will the cable tension do for the shifting function / performance?

oldskoolwrench

Todd,

The High and Low Limit screws control the physical movement of the derailleur. You can detach the cable from the Anchor bolt to adjust the High and Low Limit, and use your hand to physically push the derailleur up to the largest cog.
If it goes too far, and pushes the chin into the spokes, you tighten the Low limit screw until the derailleur is lined up with the largest cog. If it won't shift up to the largest cog, then you loosen the Low Limit screw. Same with the High limit screw (small cog).

Cable tension determines how easily the derailleur will move with the shift lever. if the cable's too tight, the derailleur won't drop onto the small cog. If it's too loose, then the Shift lever cannot push the chain to the larger cog, because there's too much slack.

We're not taslking piano wire tight with the cable here; just a slight amount of tension is all that's needed. Also... don't crank the Limit screws too much; a ¼ to ½ turn of the screw either way, then check the movement of the derailleur.

Hope this helps...

cny-bikeman

I recommend leaving the videos for seeing the actual process rather than understanding what to do. Google adjust rear derailleur and go to the parktool.com/blog and sheldonbrown.com results first. The adjustment barrel on an friction system is only for taking up slack so that you don't have to move the lever so far before the derailleur moves but is loose enough to allow movement to the small cog. It has no other function.