dynawolf

I have a 2017 Spec bike. The rear shifter acts up when the chain is in the biggest cog and I want to shift to a smaller cog. I shift one or two spaces and nothing happens. I need to shift 3 or 4 and then the chain snaps into the chosen gear. At that point, I have to shift the other way to the desired cog (ex the cog with the second most teeth). The LBS has a four week waiting period due to increased Cov-19 demand. I would rather not have my bike sitting there for a month. I am still riding, but it is a PITA...especially for a $4k bike.

Thoughts?

Iride01 

Check for a frayed cable up in the STI. That's been my issue many of the times this happens. There are other reasons though.

Price for a high dollar bike isn't for being maintenance free. It's for performance which many times means more frequent maintenance whether it's replacement or adjustment.

dsbrantjr

Check for cable fraying frequently, it happens more often with the under-the-tape routing. Check elsewhere for excess friction.

shelbyfv

Yes, classic cable impingement symptom. Frayed inner, kink, whatever. Cables need regular maintenance so if you've got three years with respectable mileage on the originals they've served you well.