Bianchigirll 

dddd yeah I kinda know that but I usually try to keep my answers short. No need to tell me about shipimano and all their tricks I'm always railing against them and their fancy buzz terms like SHipmano Leanear Response (SLR) aka "you can't use a cheaper Dia Compe or ChangStar brake levers with my brake calipers, and STi which mounted the shifters, first on flatbar bikes, directly to the brake levers to prevent mix n match speccing buy bike companies.

Triplecrank92

Thanks to all for your input so far! I've been swamped at work and at home for the last few days which has prevented me from working on the bike, much less responding to this thread. As soon as the body limbers up this morning and the coffee kicks in, I'll start playing around with all the suggestions provided to see how to get the Serotta out of the stand and back on the road.

Friction isn't a problem for me and I still use that skill set on a couple of bikes with Superbe and Cyclone setups. Like you, I grew up on a friction shifting and still enjoy it. The 7402 levers worked nicely in the friction mode when I was testing the drive train on the stand, but I'm not ready quite yet to give up on resolving the indexing problem. I do enjoy the crisp shifting of a good indexed rear DT shifter and leave the "frictioning" to the FD lever.

Over the years, I have been unwittingly fortunate in that the componentry on my bikes has mostly been the same (or at least compatible with each other: 600 series, Ultegra, 105, etc.) which helps when moving parts and pieces around. For example, it allowed me to test that second rear wheel with an 8 speed Ultegra cassette with the 7402 levers. (Sorry BG, that second Shimano wheel came off the Rasta Bianchi Giro....Sacrilegio! There are just not many Campy equipped used bikes in lower AL.) In converting the Serotta to DTs, it just didn't occur to me about the incompatibility of the 7400 series when I bought the 8 speed shifters. These "vintage" 8 speed shifters are like hen's teeth so I bought the 7402s quickly without vetting them.

If I can't get the levers to work, as I mentioned earlier, I would now now be facing "the opportunity" of acquiring the other parts of the 7400 series. Tsk, Tsk, what's a boy to do?

Triplecrank92

Well, it didn't take the 30 seconds, but maybe 5 minutes to move the cable and then calibrate the barrel adjuster to smooth out the chain's movement between the cogs. What was unexpected was the amount of inward RD movement that occurred by relocating the cable to the other side of the bolt. When repositioned, the cable pulled the RD to the point of brushing the spokes when on the largest cog. I had to reset the High and Low RD stops and then re-calibrate the barrel adjuster. I located a tabbed washer from another 600 RD from the parts bin which I'm debating putting on the bike or just torquing down the nut a little tighter on the RD to make sure the cable doesn't slip. I didn't go to the trouble of cutting a notch into the RD.

So, now the indexing is about 97-98% on target which will suffice for the time being and then I'll test it further on the road. On occasion, I had to apply a slight bit of pressure on the lever to shift the chain up to the 5th cog. But since the bike is in the work stand, the "added" pressure on the lever might not be needed once the bike is on the road and the higher cadence and torque of my weight on the cranks is figured into the equation.

Now, I just need to find another reason to buy the rest of the 7400 group set. . Thanks again to everyone's input!

KCT1986

Glad to hear that it seems to have worked. The position that the cable needs to be attached can vary a little depending the wear condition of the RD pivots & guide pulley. You may need to 'fiddle' with the cable clamping position a little.

If you are getting reasonable indexing with the cable on the other side of the bolt, the tabbed washer is not needed.

dddd

A word of caution when/if using the low-limit screw to actually change the rest position defined by the shifter's detent.

What I have known to happen on several albeit well-used bikes (and on a few such shifters sold used) is for the last-position (i.e. largest cog) detent to wear out due to the unyielding position of the lo-limit screw. This because frame flex while in the largest cog will make the detent balls move with every pedal stroke against the detent plate, wearing the Lo-position detent itself. The shift lever will then no longer hold an accurate indexed position.

The good news is that the cable's anchored position can be infinitely adjusted, perhaps a tad closer to the original path of the cable exiting the groove (why I gave a reference of 2-3 cable widths away from the original cable path).

A remotely similar problem occurs with great frequency on modern bikes having STI levers and particularly those also having the newer hidden shift cable exit.
Here, the indexing ratchet allows no motion at all in response to flex-induced cable force cycling, such that the common practice of setting the lo-limit screw on the tight or "safe" side of optimal causes the cable to over-tension with each pedaling cycle, leading to the notorious appetite for cables associated with Shimano's newer STI levers.
Campagnolo's Ergolevers don't suffer that indignity because their traditional Ultrashift internals apply only spring-limited force on the cable versus Shimano's unyielding ratchet. But their (thankfully replaceable) detenting springs will however require wildly more-frequent replacement.
Shimano's 11s STI levers, to their credit, incorporate an added degree of lever-travel limit, preventing gross stretching of the cable if the rider "slams" the lever into lo gear, but it does still have enough over-shift motion to accelerate cable failure if the lo limit is set aggressively (as it seems to be on at least half of the bikes that I work on for the first time). Often the lo-limit screw ends up too tight because of a wheel change, where a needed slight cable tension adjustment is not followed by the "mechanic" re-visiting the limit screw adjustment.

Lastly, on a friction-shifted bike, a "tight" lo-limit screw adjustment tends to cause the shift lever to slip abruptly in response to one's harder pedaling efforts while on the largest cog, causing mayhem!

dddd

I don't work for Shimano, just trying to be fair and perhaps appreciative of all the low-cost and inter-configurable parts from them that so many of us have enjoyed over the years.

Of course the parts makers like Campag, Sram and Shimano test their setups using the parts that they make and offer during the run of production, and it's quite unfair in today's diverse/competitive market for them to make parts that are suggested being compatible with other-maker's parts. Nobody does this among the big brands.

When Campagnolo or Shimano state that only their parts should be used as replacements, it is because those are the only parts that they have subjected to their industry-standard extensive testing. Doing otherwise invites huge liability implications with fingers pointing at each other in court, meaning the company goes out of business.

Suntour sold indexing gruppos that passed their performance testing, but made it too easy for bike makers to substitute the wrong chain, freewheel, cables etc, which resulted in too many bikes sold having truly sub-standard shifting performance.
Campagnolo similarly suffered from having done much less R&D than Shimano during their Synchro-shift era, but wisely provided detailed charts showing exactly which chain, freewheel, derailer and shifter detenting disc had to be used together.

As late as the 10-speed era, serious shifting problems could arise from using say a Sram 10s chain on a Shimano 10s road gruppo (notably at it's worst using largest-recommended cassette sizes), but how was this even preventable when everybody was moving independently along their own design path?

Shimano shook things up with the SIS type of indexing and later with Hyperglide-style cogs that everyone else patent-dodged around, so I guess they can be given some blame. They led, others followed, and I get that "integration" is a bad word around here in this context.

70sSanO

Glad you got them to work. Fortunately, or unfortunately, the 74XX DT shifters were the best index DT Shimano made. The audible click was loud enough to scare birds out of the trees on a quiet ride.

I done the alternate cabling and, as others have noted, you can fine tune it using the tab. Best combo I’ve run was 7401 shifter with M910 RD.

I using 6401 DT shifters and they are pretty sloppy in comparison, even NOS.

John