Creating a Dura Ace 9100 12-30T Cassette

[mimesis]

Dura Ace 9100 offers a 12-28 cassette, and an 11-30. I really like the idea of having a 30-tooth low gear, but I have no use whatsoever for an 11 tooth cog. (I don't get into bunch sprints these days.) I also really like having a 16-tooth cog, which is right in the "sweet spot" of the gear range. So I was thinking of buying a 12-28 cassette, and an 11-30, taking the 12-17 cogs from one, and adding the 19-30 cogs from the other. That would leave me with a 12-30 that I could use, and an 11-28 that I could sell to someone who likes that kind of thing.

Any thoughts about whether this would work? The only thing I've found from Shimano's site is that on the 12-28, the 17 cog is "17C," while on the 11-30, it's "17B." I suspect that refers to different ramping orientation. I'm not sure whether there'd be any noticeable impact on the shifting.

[Pierre86]

Dura Ace 9100 offers a 12-28 cassette, and an 11-30. I really like the idea of having a 30-tooth low gear, but I have no use whatsoever for an 11 tooth cog. (I don't get into bunch sprints these days.) I also really like having a 16-tooth cog, which is right in the "sweet spot" of the gear range. So I was thinking of buying a 12-28 cassette, and an 11-30, taking the 12-17 cogs from one, and adding the 19-30 cogs from the other. That would leave me with a 12-30 that I could use, and an 11-28 that I could sell to someone who likes that kind of thing.

Any thoughts about whether this would work? The only thing I've found from Shimano's site is that on the 12-28, the 17 cog is "17C," while on the 11-30, it's "17B." I suspect that refers to different ramping orientation. I'm not sure whether there'd be any noticeable impact on the shifting.

Depends on what cogs are on held together on the carrier. I did a 105 12-28 because I didn't want to have to buy Dura ace every time I needed a cassette.
Every now and then it would take an extra half a revolution or so to change from the 17 to the 19 as the ramps are slightly different, but as a whole you probably won't notice the difference very often

[pdlpsher1]

Since the 12-17 cogs are steel, you might as well buy the Ultegra 12-25 cassette instead and save yourself some money. Then you can sell the 11-25 Ultegra/Dura-Ace hybrid cassette without losing too much money.

[LAN]

I have done this and it works fine.

The 17C is "in sync" with a 16 cog, while the 17B is in "sync" with a 15 cog.

So if you use 12-17 form a 12-28 and the rest from a 11-30 it should work perfect.

[Ritxis]

Dura Ace 9100 offers a 12-28 cassette, and an 11-30. I really like the idea of having a 30-tooth low gear, but I have no use whatsoever for an 11 tooth cog. (I don't get into bunch sprints these days.) I also really like having a 16-tooth cog, which is right in the "sweet spot" of the gear range. So I was thinking of buying a 12-28 cassette, and an 11-30, taking the 12-17 cogs from one, and adding the 19-30 cogs from the other. That would leave me with a 12-30 that I could use, and an 11-28 that I could sell to someone who likes that kind of thing.

Any thoughts about whether this would work? The only thing I've found from Shimano's site is that on the 12-28, the 17 cog is "17C," while on the 11-30, it's "17B." I suspect that refers to different ramping orientation. I'm not sure whether there'd be any noticeable impact on the shifting.

Cassette 11-30..............remove 11 cog and lock ring, add an 16 or 18 cog (your choice) can be from a cassette of 10 or 11........ 11 speed spacer and lock ring for 12 cog......you already have a cassette 12-30

[LAN]

This is not correct.

The 11-30 already have a 15 and 19 cog, it´s the 16 cog that is missing.

Also there is a difference between a 12 cog 1st position (12-25/12-28) and a 12 cog 2nd position (all other rations)

You can just buy a 16 cog and put it in, but you will not get usual Shimano level shifting performance between 15-16-17 cogs since the ramps are out of synch

[Ritxis]

This is not correct.

The 11-30 already have a 15 and 19 cog, it´s the 16 cog that is missing.

Also there is a difference between a 12 cog 1st position (12-25/12-28) and a 12 cog 2nd position (all other rations)

You can just buy a 16 cog and put it in, but you will not get usual Shimano level shifting performance between 15-16-17 cogs since the ramps are out of synch

Edit.....edited ......... things to see on the phone and not on the pc monitor....

it is still using the cog of 12 of 11-30....you only eliminate 11 and the lock ring for 11......it is clear that some of the efficiency of a cassette is lost without modifying...but the result is satisfactory

on my bikes I have never used cassettes with 11 and 12......I modify them to my liking and uses and they work well for me

in my 2 current bikes I use a 13-30 and a 14-30 (winter bike)
1 cassette with 10 and 11 Shimano cassette cogs and a Miche cog of 30, and the other one even with a spider (24-27-30) from an XT 11 cassette......Very happy with the result