bikeboy3326

Hello Folks, First time building my own road bike mostly via youtube videos (it's been a real challenge and learning opportunity). I've played with all the adjustment screws on my Ultegra RD-8000 medium cage (GS) to the point where it shifts up and down nicely to all but the smallest cog. I've gotten to the point of considering taking the bike into a shop . But first I figured I tried online community for a few ideas to try out:

1. Did I mis-calculate something and I should have gone for a small cage derailleur? Drivetrain capacity is (30-11)+(52-36) = 35
2. Maybe I cut my chain too small or too big? Followed several you tube videos
3. Not enough tension in my shifter cable?
4. Maybe the derailleur is installed the wrong way?
5. Maybe there is one hidden magical adjustment screw that i haven't tried?

Wish I could post some pics but since I am a newbie I need to have 10 posts before doing so (ridiculous rule...I already passed the "I am not a robot" test.
My specs are:
Cassette: CS8000 11-30 11 speed.
Front Chain Ring: FSA 52-36
Chain: Shimano 11s chain with quick-link
Shifters: Ultegra ST-R8000 STI 11speed

Any ideas I can try? Thank you in advanced!

tagaproject6

Check if the derailleur hanger is not bent.

rms13

Definitely should be compatible. What is the frame? Any chance the deraileude hangar is misaligned? Read the manual. I haven't worked with that model and there might be some quirk. Find a video that is specifically installing that model if you can . But in general, remove cable tension, set the limit so the chain is in smallest cog without the cable being clamped, adjust barrel adjusters then clamp the cable and work on indexing

Racing Dan

" to all but the smallest cog"

Or the H limit screw is set too tight.

phtomita

^^^^ probably this

Dean V

+2
or you have got too much tension in the cable and are not getting to use all the clicks in your shifter.
Undo cable from derailleur and then see if it will shift into the smallest cog.
Adjust limit screw as required.
Make sure shifter is on the last click.
Re attach cable and adjust with barrel adjuster to get it shifting properly.

mynewnchome

Park tools video really got me on the right track....took one I bought last week that was having shifting issues to butter smooth. There's a process and if followed seems to work.

Racing Dan

This is hard to argue with, but damn their videos are long. Makes it appear as if it is rocket science. There are only a few adjustments needed to be done. In a stand its a two minute job.

While we are at it. - Why is it always advised to set indexing/cable tension in the smallest cog. Seems like an odd choice when the H limit has the potential to interfere and confuse the user, if its set too tight. For that reason I always adjust cable tension somewhere in the middle of the cassette. This separates the cable tension adjustment from the H limit setting.

2cam16

I do the same thing.

bikeboy3326

Thank you, The above did the trick.

redlude97

Unless we watched different videos they set indexing on the second to smallest cog which would be unaffected by limit screws. They only set initial tension to get the first shift to occur with the first click which you probably do automatically already do without realizing