Swap 11T to 12T on Ultegra 11-34 11 speed cassette?

[NHAero]

On the new Ultegra 11-34 11 speed cassette, is there an easy swap of the small 11T cog for a 12T cog?

[Look585]

Yes, you can order at 1st position 12th cog and replace the 11. I got a couple at JensonUSA.com

[NHAero]

Are the cs-6800 cogs compatible with the cs-8000 cassette? Thanks

[dave thompson]

When you change from 11t to 12t cog, you also need to change the lockring to one for the 12t.

[Look585]

Are the cs-6800 cogs compatible with the cs-8000 cassette? Thanks

Yes, they seem to be identical. Both are "B" clocked and the 12>13 shift works great.

http://www.jensonusa.com/Shimano-Ultegra-6800-11-SPEED-Cog

When you change from 11t to 12t cog, you also need to change the lockring to one for the 12t.

Nope, the 12t 1st position cogs I received use the same lock ring as the 11t.

https://farm1.staticflickr.com/905/42157206162_4495bdf85d_z_d.jpg

https://farm1.staticflickr.com/905/40396628280_f018673cbb_z_d.jpg

https://farm1.staticflickr.com/826/40396627490_815c79d3f5_z_d.jpg

[NHAero]

Thanks so much!

[NHAero]

12T cog arrived and fits and shifts perfectly - thanks!

[unterhausen]

I should do this

[NHAero]

It lets me go from the 41T big ring I was planning to a 44 or 45, which is better across the range without losing the top end. Also nice to have 13 to 12 instead of 13 to 11.

I got it on eBay and it showed up in 2 days!

I should do this

[NHAero]

This is a follow-up. I'm running a 44-33 chainring combo with the 12-34 eleven speed cassette, and 37-622 tires. Gear-inches are 26.5 to 100. What I really am liking is the ability to stay in the bigger ring most of the time, compared with when I ran larger big rings. I'm thinking of changing cranks to a set that could accept a smaller inner ring for even lower gearing when really needed.

[unterhausen]

I have gone to a 46 large ring and being able to stay in the big chainring most of the time is really nice. With the 50, I was always shifting. Back when I was stronger, I rode a 44 small chainring and noticed that was really convenient for most of my riding.

[NHAero]

The other benefit is better chainline. The most common gears for me to be in now are the 44 front and the 19-21-23 rear - the 21 is the middle of the cassette. With the triple crankset I ran for many years, I was often shifting back and forth between the big ring and the middle ring and rarely in a direct chainline.

I have gone to a 46 large ring and being able to stay in the big chainring most of the time is really nice. With the 50, I was always shifting. Back when I was stronger, I rode a 44 small chainring and noticed that was really convenient for most of my riding.

[charliedid]

Good idea.

[m_sasso]

Late to the party however here is a condensed version.

You can assemble an 11s Shimano 12-34 cassette by doing the following:

Buy HG800 11-34 Cassette.
Buy 6800 12t 1st position cog.
Throw 11t 1st position cog in the drawer/toolbox/dumpster.
Mount 12-34 cassette (no special lockring needed, the HG800 is fine).
Go Ride.

JensonUSA stocks the 12t 6800 1st position cog.
https://www.jensonusa.com/Shimano-Ul...0-11-SPEED-Cog (https://www.jensonusa.com/Shimano-Ultegra-6800-11-SPEED-Cog)

[crankles]

I should do this

I AM going to do this!