DA 7400 partial upgrade?

[joelh]

I am running DA 7400 with shimano 600 brifters and can not get the rear shifting right. My options seem to be; find 7400 brifters, put a 600 rear der. on and continue to run 8 speed, or upgrade.

I am wondering if I can do a partial upgrade to a DA 9 speed group. New brifters, rear derailleur, cassette, and chain. That would leave brakes, crank and front derailleur as 7400. Does this make sense, or should I just put a 600 rear derailleur on it and save up to upgrade the whole thing?

[thwart]

If memory serves, pre-7700 DA indexes differently than the rest of the Shimano line. So DA shifters and RD should match. FD too (I think...) but much less important.

I'm sure someone else here has more knowledge about '90's Shimano stuff, though.

So the most cost effective solution: replace that DA RD with a 600. Easy to find on the 'Bay.

Actually, you'll probably make a few $ on the exchange... and in my opinion, be running higher quality stuff than some of the newer Shimano components.

[regularguy412]

I have 7400 DA on my TG and have been running (up to now) 7400 DA on my CSI. The CSI stuff had about 30,000 miles on it and I, too, was having problems getting rear shifting set 'just right'. It either wanted to shift up properly or shift down properly, but never both at the same time. I thought at first it was wear in the rear der. pulleys. Replacing the pulleys helped as did replacing the chain and rear cogs, but none of this cured the problem. I also changed all the cable and housing, as well as lubing all the other points (under the BB) where the cable has friction against the shell. There was no 'play' that I could discern in the rear der. parallelogram pivots. I finally put it off to just plain excess wear in the shifter mechanism inside the shifters. I was having to set the rear der. such that upshifts to a harder gear could be made normally, but I would have to slightly overshift the lever to accomplish the downshift. This became more difficult to do, over time. I finally have bitten the bullet and will go to 10-speed on my CSI when I get it back from Serotta. I was lucky enough to get upgrade parts for it for Christmas :).

I managed to find some NOS 8-speed DA shifters on Craig's list last year for $200. They now see service on my TG. You might luck onto some if you are vigilant on eBay and CL.

Good luck.

Mike in AR:beer:

[Gothard]

Thwart is right. The 7400 brifters/derailers only like themselves and are not compatible with lesser stuff.
The 7400 is also damn near impossible to wear out.

[Dave Hickey]

I am running DA 7400 with shimano 600 brifters and can not get the rear shifting right. My options seem to be; find 7400 brifters, put a 600 rear der. on and continue to run 8 speed, or upgrade.

I am wondering if I can do a partial upgrade to a DA 9 speed group. New brifters, rear derailleur, cassette, and chain. That would leave brakes, crank and front derailleur as 7400. Does this make sense, or should I just put a 600 rear derailleur on it and save up to upgrade the whole thing?

If you are using a 7400 rear derailleur, it is not compatible with 600 brifters... If you want to continue to run DA 8 speed and use brifters you have two option..

1. Find an old pair of 7400 brifters
2. Use 7700 brifters- It's not widely known but the 7700 brifters will shift 9 speed when connected to 7700 rear derailler and will shift 8 speed when connected to a 7400 rear derailleur. This works because of the unique pull ratio of the 7400 rear. It was designed that way by Shimano. No special cable routing. Just hook up the 7700 shifters to 7400 rear and viola! 8 speed shifting...(don't use the extra click)

My JP Weigle is set up with way( I'm using 7700 DT)..perfect shifts every time..

Here is a pic of a Dura Ace barcon..You can see that it says it works with 7700 rd for 9 speed and 7400 rd for 8 speed