AlexCyclistRoch

I'm in the final stages of preparing a classic 80's Cannondale, but I just can't get it to shift as properly as I'd like. It's got a very low mile 600 tri-color rear derailleur, and the original indexing 105 downtube shifters on Rivendell bar-end pods. The cables are new Jagwires. The chain is brand-new SRAM, and the cassette is a Shimano 7-cog "M" that looks to be fairly low in miles.

The problem is that I can't find a 'happy medium' where upshifts and downshifts both work perfectly. I adjust one way, and upshifts are slow, requiring an extra nudge. Adjust the other way, and downshift require an extra nudge. I have it set now such that the nudge is required for going up to larger cogs. I've never had a Shimano or SunTour indexing give me this much grief!

I'm suspecting that the problem lays in one of 2 different issues: either the extra cable length is giving me issues with stretch or internal friction, or else the internal indexing in the shifters is just worn enough to not work well enough. Any observations or suggestions?

BTW, if I do replace the shifters, I was wondering if those new 8-speed Sora downtube shifters that retail for about $30 are worth considering? Old equipment is always a crapshoot, so don't suggest going EBay for used shifters. Anything NOS is just too expensive for my tastes. Or, any other alternatives, Shimano or not? I do wish to stay with indexing, BTW.

Whit51 

Make sure cable tension is not too slack or too tight. You could also let all the tension out of the cable and start over, adjusting the tension with the chain on the smallest rear cog. I think Park Tools site still has a tutorial on setting up indexing. I mounted some Suntour Sprint indexed downtube shifters on Riv pods and they indexed well after some fiddling, to my surprise. I've had a harder time getting Shimano 8-speed barcons set up right. If all else fails, you could mount some friction shifters on the pods!

Andrew R Stewart 

Shimano frame mounted shifters of that era sometimes had an internal issue which changed the movement of the lever and it's indexing nature. There is a small stared "washer" inside the RH shift lever which can crack easily. Is cracked it then allows the lever to rotate further before the indexing feature is engaged. More pull back to down shift then more "trimming" forward to settle the indexed position.

I have seen this many times and one only knows this after taking the shifter off it's boss and the little "washer" falls away in pieces. This forum just had a thread a few weeks/months ago about this.

Does the shifting work well when the lever is set to friction? Andy.

AlexCyclistRoch

yes, actually, it does. But the engineer in me still wants indexing, and wants it to work CORRECTLY, too. Is that Sora 8-sped indexing downtube shifter they still sell any good, and is it totally compatible? Is there a Suntour/SRAM equivalent that is any good? I love 'classic' shifters, but it's time to buy something new....

bikemig 

You can still buy 8 speed shimano bar ends:Shimano Ultegra 6480 8sp Bar End Shifter Set | Chain Reaction Cycles

If you buy these, I might be interested in your rivendell pods, .

Btw, you need to get some spacers to make the pods work with downtube shimano shifters but you probably know that.

https://www.rivbike.com/product-p/sh21space.htm

bradtx

ACR, The R400 shifters worked well for me for several years. Description: https://www.worldwidecyclery.com/pro...FQyHaQodtLUF4Q

Brad

Trakhak

If you haven't already done so, use an alignment tool to check whether the derailleur mounting tab is bent.

rccardr 

Are you trying to shift a seven speed freewheel with a six speed shifter? 1050 is 6 speeds, 1051 and 1055 are seven speeds. That might be your problem, right there.