I wanted to take advantage of the new Ultegra CS-R8000 11 speed cogs but I do not trust indexed or electric shifters to last >10 years so I opted for bar-end 11 speed setup. I could do this using my current 8 speed bar end Ultegra shifters.
I purchased an 11 speed chain (SRAM PC1170), and Ultegra 11-28t cog set but found that the CS-R8000 cogs did not fit my ~1997 wheel that has CS-6800 8-speed Ultegra cogs. There was no spacer between the cogs and hub and the 11t cog extended off the end of the hub. I could put 10 of the 11 gears on - however they were not firmly mounted.
The solution was to put the 12 to 28t gears of the new cog on and use the locking ring from the old 8 speed.
I am still using the 8-speed derailleur and bar end shifter and rings (39-50) that came with the bike.
Note I had only this summer replaced the original chain on the bike with a Sedis 8 speed as the original had no measurable wear but ~25 years of used seemed like enough. I'd estimate that ~15,000 km was put on the original chain and gears.
Problem:
The 3rd smallest cog presented problems while shifting.
I could not reliably shift up or down to it. I could adjust
the system every which way; but it was not possible to make it shift both up and down
smoothly.
This problem is slightly worse for the outer ring. I've had a 42, 50 and 53t
outer ring on this bike. I've changed the cogs thru 7 spd Ultegra to 8 spd ones.
I've changed the shifter as well and the problem persists. I've not changed the
derailleur but have no reason to think that it is at fault. I've adjusted the
B-tension screw as far as possible. ie removed it.
After having gone to 4 different shops via 6 visits and spending hours with this
bike myself the problem was still present.
I'd declined an offer to send the bike back to Klein due to the hellish
times I've had dealing with Canadian Customs. ie I would probably have to end up paying duties, handling and brokerage fees all over again! Let's just say that I was not
happy with the shop that sold me this bike and have not delt with them since their two attempts to fix the bike.
Here is a close up picture of my fix. I basically re-routed the shifter cable so
that it rotated the derailleur counter clockwise. This was done by routing it between
the wheel axle and the derailleur and tying it in place with a ty-wrap or piece of
wire.
This results in more chain wrap (5 deg extra rotation of the derailleur)
and greatly improved shifting. My theory is that the Quantum I had the top
derailleur pulley closer to the cogs than the Quantum II setup. One of the main
reasons why the older Campy indexing didn't work at all was because they had
too much space between the cogs and the top pulley so that the chain flex prevented
the derailleur from forcing a shift. Personally, I hate Campy with a passion; it's
over-priced, over-polished and under-engineered. It took them years to adopt the slant
parallelagram [to their credit they did have one with an adjustable slant so that it
could better adapt to a variety of cog ranges] and get any sort of indexing system
actually working. On the flip side I'm not partial to Shimano constantly changing
things. For example I see no use for 8 cogs; esp. a 12 tooth one. I rarely use a 13t
and I'm never going to use a 12t.
With this setup I still get hesitation and often have to nudge it
to get it to shift from the 3rd into the 4th and 5th cogs. I've set it up so that it shifts to the smaller cogs
fairly reliably since I can't nudge shifts in that direction. When shifting to larger cogs I simply nudge the
system by partially pushing the shift lever enough to slightly pull the cable;
but not enough to cause it to lock the ratchet for the next gear.
The bike shops had replaced the cables, torn out all of the internal cable guides and the shifting was not in the least bit improved. I've been an amateur team mechanic and cyclist for many years; building bikes for friends and was similarily stumped after hours of adjusting the setup. Only after noticing that the bike would shift if I pull/pushed the derailleur closer to the cogs did I come across this solution. With my bike on a stand I can advance the shift leaver and the bike will not shift; but as I rotate the derailleur up it will shift. Anything that positions the derailleur closer to the cogs reduces the problem. Since a close tracking of the top pulley to the cogs is necessary for the indexing to work my theory is that the pulley is not close enough. Still, I can't image why, if that was the problem, only one gear is affected.
My uninformed guess is that the dropout change from the Quantum I to the Quantum II
is responsible since it probably placed the derailleur further forward and/or lower thereby putting the top
pulley further from the cogs. The Quantum I has a normal
dropout while the Quantum II went to a "micro" dropout for reduced weight.
But that is just speculation. My Quantum I was T-boned by a car on the right side
and I don't have any pictures of the dropout and derailleur position. Yes, I've been in a
few accidents and missed quite a few. Take a look at my Automorons web page for the tales.