ultralight 12t 12s pulleys for sram red

[arcadia]

Hello,

As I plan to build a 1x12 mechanical sram groupset, I ordered several parts:
-a pair of brand new double tap sram shifters
-a wifli derailleur, which I hope to work on a 10-33 1290 cassette at least for now, then maybe design a ultralight 12s cassette?!
-a set of ratio technology ratchet and pulleys
-a set of extralite ultrapulleys I found for discount price, more for study that for actual use.
here are pulley specs:
-sram 7,3mm overal thickness, 4mm hole on guide pulley, 5mm diameter on bottom pulley
-ratio technology 8mm thickness, and 5,2mm hole diameter
-ultrapulleys 8,35mm thickness and 5mm hole diameter
The problem is if you don't use a 4mm diameter on guide pulley, you will loose a lot of accuracy on shifting, this has been tested with a friend, on another sram red derailleur.
So I designed my own pulley, for 12s sram chain:
-1,9mm thickness
-4 and 5mm holes on washers
-double micro bearing, full ceramic
-machined delrin 12t design
From what I found, the bearing set would be about 1g for steel, 0,8g for ZrO2 and 0,4g(!) from Si3N4, making the pulley set weighting from 8,25g with steel bearing to 7,5g for the Si3n4 bearing
For now I ordered a set of zircone bearing to build a prototype
If that works, maybe it should be interesting to produce some for weenies?!

[Kayrehn]

Yes please, I have been eyeing the Extralite ones for a long time but the price is really steep for the weight savings. I'm on 11 speed still though.

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[arcadia]

I don't think the result will be cheaper, it can' t be possible to make small quantities for lower price, I paid 40$ just for the bearings, however, using steel bearings could lower the price, as those are much cheaper and easy to get, and the weight saving is just 0,4g for the set, compared to zircone bearings, this will depend on machining cost, depending on quantities.