Affordable Weight Fanaticism (Again!)

Used, but freshly cleaned, pg850 11-32 cassette.

Hmm. I shaved, and weighed my beard.
Because every gram counts, right?
(3 grams was all it weighed!)

On a more sensible note, I have been thinking about aluminium rear cogs.
If one can buy an affordable chainring in 6061 or 7075, why do there seem to be few (if any) similarly sized rear cogs available.
I'm not taking about the small sizes, like 11s through to 20-ish.
I am talking about the larger rear cogs, like 28 to 36.



Yes, "range expanders" are available, but they tend to have 40+ teeth

I have been using a steel 11-32t SRAM pg850 cassette for a few years now.
It is mid-weight, not super-light, but not super heavy.
What I want is something to replace the top cog (or two) on my existing cassette.

I could go ultra fancy, and get something like a Miche SuperType cassette, but with ALL the cogs being alloy, I would have durability concerns with the smaller cogs.
An 11-speed SuperType cassette seems like an expensive way to just buy a couple of ratios, being priced at £178 + shipping, while my pg850 cost me just £15 (from Halfords).

Moving on, then, could I just buy a single lightweight Miche ring?

Well, it turns out I can.
I can get a Miche Primato 11s ring. Although the smaller sizes are all still, they make a 30t and a 32t that are alu.
Price £18 (new, inc shipping, eBay)

Of course, the orthodox choice would be something like an SRAM pg980 11-32 with the largest three cogs being mounted on an aluminium carrier to save weight - and only costing £33 from Halfords or Wiggle.
But that would be too easy ;-)

SRAM pg980 - all steel rings, but the largest three are mounted on an alloy carrier