No because the 11 speed derailleur has different geometry than 10 speed.

Is the cassette actually a 10 speed cassette, or is it an 11 speed that had a cog removed?

You can use an 11 speed cassette on a 10 speed freehub body as long as you take out one of the cogs and move a spacer to behind the cassette. Dark Speed Works has a tutorial on their website for different variations of this.

What was wrong when you put your 11 speed zipps on?

---

Strava

I'm not sure. I'll try to figure out the spacing. Let's assume the original wheels came with 11 speed, but with a cog removed. Would it have worked well then with a 10 speed shifter? You would have to specially set the upper or lower limit screws to keep it from coming off, right?

When I put my zipps on (11 speed), i get access to the full range of gears, but there are a few in the middle where they will skip or bounce back and forth between gears.

No I don't believe it would work with a 10 speed shifter. Shimano changed the cable pull ratio when they made their 11 speed groupsets.

Yea, you would need to set the limit screws for the cassette. But that should be checked anyway when you get a new bike.

As for the zipps, it sounds like the derailleur just needs to be adjusted (assuming it's an 11 speed chain).

---

Strava

Well, I did take it in to get a bike fit, and they tuned it up for me all without noticing that an 11 speed bike as a 10 speed shifter.

Thanks, I think I have what I need to figure out how much the original owner is at fault.

Why don't you just get a 10 speed rear derailleur or an 11 speed shifter and move on with life?

The bike is in the shop right now getting an 11 speed shifter put on, but I may be missing a race this weekend due to shipping the part in. I'm trying to get all the facts together for PayPal buyer protection. There are other simpler issues I am working through with the bike too.

Since the pull ratio is different between 10 and 11s derailleurs, there is no way that that this set up would have worked across cassette. A few cogs, maybe, but the derailleur would get out of alignment with the cassette pretty quickly during shifting.

They have a different cable pull ratio. Shimano made a choice to make it that way.

SRAM didn't.

---

___________________________________________
http://en.wikipedia.org/...eoesophageal_fistula
http://en.wikipedia.org/wiki/Cerebral_palsy
2020 National Masters Champion - M40-44 - 400m IM
Canadian Record Holder 35-39M & 40-44M - 200 m Butterfly (LCM)

After PayPal rules in your favor, you will be required to ship the bike back at your expense and you will be given a refund.

Thank you for the scare, but the owner has agreed today to do a partial refund to cover the parts and labor.

I also learned that while the bike tech told me the derailleur was an Ultegra 6800 (11-speed), it is actually 6700 (10-speed).