Bicycle Mechanics - Adjusting New Drive Train?

I'm trying to finish the build on my old-school road bike in the event that Spring ever actually arrives here in Chicago.

I'm having trouble adjusting my rear derailleur and would be grateful if someone can advise me. I paired up a (new old stock) Shimano 600 SIS 6-speed rear derailleur with 6-speed SIS downtube shifters. These should be a perfect match because they're RD-6208 and SL-6208 respectively. I'm using a Shimano 6-speed indexed freewheel (14-16-18-21-24-28) with the original Sakae crankset (40/52) and a new SRAM Power Chain rated for 6-7-8 speeds.

Two cogs are causing me trouble. When I shift down (toward the larger cog,) the chain jumps over the 18 to the 21. When I shift up (toward the smaller cog,) it jumps the 21 to the 18. I've adjusted the upper and lower limit screws, the cable tension, the chain length and even the "B" screw. I'm running out of things to adjust.

Any suggestions?

I'm betting that you haven't checked the alignment of the derailleur hanger. If it's off a little bit, it can make it shift the way that you describe.

Oh, and good luck about spring coming to Chicago sometime soon.

I'm betting that you haven't checked the alignment of the derailleur hanger. If it's off a little bit, it can make it shift the way that you describe.

Uh-oh. Is there any way to do this without buying a $50 tool? Or, should I just bite the bullet and have it checked at the LBS?


Oh, and good luck about spring coming to Chicago sometime soon.

Define soon. We can usually count on it by late May...for about two days before it's 90 degrees.

Uh-oh. Is there any way to do this without buying a $50 tool? Or, should I just bite the bullet and have it checked at the LBS?
.
Bite the bullet

Uh-oh. Is there any way to do this without buying a $50 tool? Or, should I just bite the bullet and have it checked at the LBS?

Well, you're not happy with the shifting the way that it is now and it's about a $15.00 project at the LBS assuming that you act before spring hits. To me it would be worth that much just to rule out derailleur hanger alignment as a potential cause of your shifting problem. I'm pretty sure that's your problem.

http://www.utahmountainbiking.com/fix/rhanger.htm

Well, you're not happy with the shifting the way that it is now and it's about a $15.00 project at the LBS assuming that you act before spring hits. To me it would be worth that much just to rule out derailleur hanger alignment as a potential cause of your shifting problem. I'm pretty sure that's your problem.

That sounds like the way to go. I just had it in my head that this bike would be a 100% DIY project. Sometimes you just have to recognize your limitations, I guess.

Thanks.

Believe RG is correct but before you spend any money go to the hardware store and purchase a fine threaded 10mm rod as reviewed in phanto's excellent link just above. May also be some cable stretch in the mix as part of break in also if you are starting all fresh.
Good Luck,
George

Believe RG is correct but before you spend any money go to the hardware store and purchase a fine threaded 10mm rod as reviewed in phanto's excellent link just above. May also be some cable stretch in the mix as part of break in also if you are starting all fresh.
Good Luck,
George

If you're going to try to adjust the hanger yourself, it's important to use the threaded rod or a bolt, the screw in gauge like the bike shop will use, or even your derailleur threaded into the dropout. If you don't you can deform the threaded hole in the dropout and your derailleur won't thread into it afterward. A couple of times I've done mountain bikes on the trail by just bending the derailleur back with my hands and gotten it straight enough to ride back to the car.

Thanks to all for the help.

I did have a crash on the right side last fall so the bent hanger theory makes a lot of sense. I'll try the bolt idea before hauling it off to the LBS.

Oh, and I do have new cables and I've stretched and tightened them up several times.

This is fun. Frustrating, but still fun.

don't be plussed at all by any of it. Its only parts and you will sort it out and likely build many more bikes and help others with theirs.
Have fun with it.
George