1x9 with expander - options

The Rookie

Toying with the idea of fitting an expander on my 1x9, I am currently using an XT cassette with the largest 6 gears on a spider, I don't want to add too much weight and have considered the following two options
Expander + XT cassette replacing gears 7/8 with a new single gear (Formatting will probably be lost when posting!)
Gear Teeth% change
1 40 17.6
2 34 13.3
3 30 15.4
4 26 13.0
5 23 15.0
6 20 17.6
7 17 21.4
8 14 27.3
9 11
This gives fairly tight ratios with a slightly larger gap between 7 and 8 and a quite large gap between 8 and 9 where it's probably of least relevance.
Or using the largest 3 cogs from an SLX cassette (on a Spider) plus the top 3 from SLX (or XT) and then mixing up gears 5,6 and 7 to create
1 40 17.6
2 34 13.3
3 30 15.4
4 26 18.2
5 22 22.2
6 18 20.0
7 15 15.4
8 13 18.2
9 11
Worst ratio gap is now in the middle from 6th to 5th.
Any thoughts?

The Rookie

Can't believe this hasn't got any comments at all!

Chunkers1980

Who cares? They are your legs. You're an analytical kind of guy I'm sure you'll work out if it's any good for you.

buddy_club

I'd rather have the big gap between 8 and 9

The Rookie

[url=http://www.bikeradar.com/forums/viewtopic.php?p=19673237#p19673237]Chunkers1980[/url] wrote:

Who cares? They are your legs. You're an analytical kind of guy I'm sure you'll work out if it's any good for you.

Well I think the XT cassette option is the better of the two for the reasons BC has given, but before I jump into it I was hoping for someone to confirm i hadn't made a horlicks of my assumptions somewhere!

supersonic

If you hover around the middle of the cassette more and an occasional big gear then the former. If want smaller jumps at the top end then the latter.

The Rookie

I tend to use the middle most, plus if I go for a 36t chainring then 8 will be taller than my old 8th so the gap to 9th shouldn't be a big issue.