Originally Posted by
KCT1986
A possible work-around is to use the alternate cable routing method. This entails clamping the cable in a slightly different position. You would want to replace the washer with one with a tab to make installation easier. This change in position of the cable will enable the RD-6401 to emulate the actuation ration of the RD-74xx. This should work reasonably well. Try to 'tune' the cable tension while in a middle sprocket. This will minimize any variance on each end of the cassette as much as possible.
Originally Posted by
dddd
. with your existing 64xx-series derailer I would simply route the cable to the other side of the pinch bolt without any sharp bend in the cable. Done this a few times".
Originally Posted by
Kontact
the OP can swap the cable location in 30 seconds and try it. Nothing to buy, nothing to take apart.
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!