RobRobinette

[UPDATE: I took it to my LBS and the owner troubleshot it while I waited. It was a jammed shifter and will have to be replaced. Shimano is sending a new shifter but I will have to cover labor for the swap.]

I'll start by saying I have googled the crap out of this problem and didn't find an answer. I also searched this forum.

I have a one year old drop bar gravel bike with about 1200 miles on it with 8000 series Shimano Ultegra shifters and running gear. The right shifter (Ultegra ST-R8020) will now only select the cassette smallest and second smallest gears. When I attempt to select the next larger gear the shift lever won't move-just like it normally does when you reach the largest gear to prevent overshifting. The problem happened suddenly--during a ride it worked normally and then boom--only two gears available. It's as if the shifter's indexing is off (I don't even know if the lever is indexed).

I can move the rear derailleur by hand to all the gears so it doesn't seem to be the problem. When I do this the excess inner cable easily slides into the outer cable (cables are internally routed through the frame).

I verified the cable didn't slip--I re-adjusted cable slack and that wasn't the problem.

I also cleaned the shifter mechanism with WD-40 (I know I will now have to properly lubricate the mechanism).

I verified there is no interference from the shifter boot--the boot doesn't even get near the shift mechanism, it has a plastic cover between the boot and mechanism to solve the old boot interference problem. The boot and cover look exactly like the normally functioning left side (front derailleur) shifter.

Any help would be greatly appreciated.

dsbrantjr

Check inside the shifter for a frayed inner cable. Otherwise it may be warranty time: https://bike.shimano.com/en-US/infor.../warranty.html

RobRobinette

Thanks for the suggestion and link ds. I pulled back the boot and popped off the plastic cover and I can see the inner cable coming out of the ferrule and the cable looks good. There's no fraying at the derailleur end either. The cables are internally routed through the frame. I can see the inner cable move in and out of the ferrule during the one available shift and everything looks normal.

blamester

Loosen the pinch bolt on the derailleur.
Now try and shift the shifter while keeping a little tension on the cable.
See what happens?

RobRobinette

blamester, I loosened the pinch bolt and I can pull the outer and inner cable out of the frame exit hole near the handlebar so it doesn't appear to be a cable issue. The shifter does the same thing. It will do one click up and one click down only. Even with the inner cable loose after one click the shifter feels like it has shifted to the final, large sprocket and won't let you shift farther.

bargainguy

Here's how I determine if it's the shifter or something else.

Grab a handful of shift cable along the down tube, and "shift" into each gear by pulling the cable away from the frame.

If you can shift into each gear this way, the problem is the shifter, or at least somewhere between the down tube and shifter.

If you can't, then the problem is not the shifter, it's somewhere between your down tube and the rear derailleur.

RobRobinette

bargainguy, I can indeed shift the derailleur by pulling the cable where it enters the frame near the handlebar so the problem is between there and the shifter. It's looking more and more like it's the shifter itself.

alcjphil

My guess? The shift cable may have slipped at the pinch bolt on the derailleur

RobRobinette

That was my initial thought too but the above troubleshooting eliminated that possibility.

bargainguy

Then I'd remove the shift cable and reinstall it just to make sure the cable isn't binding or pinching anywhere near the exit point/ferrule on the shifter itself. If a clean reinstall does nothing, then it probably is the shifter, as you've eliminated pretty much everything else.

blamester

You can always try wd40.
Is there a rattle in the shifter.
Or give it a good rattle maybe there is something stuck in there that you can move.
Did you keep tension on the cable when you shifted the lever?

RobRobinette

I verified the inner cable slid smoothly, inserted the cable end into the shifter, moved the derailleur by hand onto the 4th from smallest sprocket and tightened the cable pinch to make sure there was plenty of tension on the cable, verified the cable end was completely seated deep in the shifter and the shifter does the same thing, one click up with a gear change up then no more, then one click down then no more. The shifter it is.

I contacted BikesDirect.com for the in-warranty repair. They said Shimano will require a bike mechanic to diagnose the failure so I took it to my LBS and the owner troubleshot it while I waited. It was a jammed shifter and will have to be replaced. Shimano is sending a new shifter but I will have to cover labor for the swap.

Thanks everyone for the help, I do appreciate it.