Been there, done that, found no matter what you need to change gear way too much on an MTB with a close ratio cassette. Fine for DH, but for XC the standard 11-32 9 speed is about spot on I reckon (well, unless you go 10spd with 11-36!).

One less ring, with a wider ratio cassette is the way forward IMO.

Can get silly light wider range cassettes too if you shop about and don’t mind spending mega bucks.

Losing a chainring up front is likely to save you more weight though. And constantly shifting to find the right gear was a PITA with a 12-27 on an XC bike.

Go 10spd, honestly! It’s bloody ace… In fact, on one of my bikes I’ve gone 1×10 with a 32 ring up front, and 11-36 out back, and its pretty much all the gear ratios I ever need. Any lower than 32/36 and I just have to tell myself “get out the saddle, people ride up here on a singlespeed”, and any taller than 32/11 and I’m spinning out going downhill on tarmac anyway.

sram do an 11 – 28 road cassette.

You can get a Middleburn 5-bolt compact spider and the 58mm and 94mm rings for 20T, 30T and 42T. Remember Shimano front mechs like 12 teeth difference or they do not change to the larger ring easily.

I bought a few 20T granny rings from these guys recently…truly a bargain.

http://www.bikedock.com/home?page=shop.product_details&flypage=flypage-bd.tpl&product_id=1246&category_id=13

PaulD

Why was say 32 x 16 more wrong more often than it would have been in the middle of a less closely spaced cassette?

Did the fact that there was another gear really close by make you think more often about whether you were in the perfect gear?

Think Surly used to do a chainset for the snow bikes on the Iditarod race. Called something like a Mr Whippy or Mr Whirly or something.