11-27 SHIMANO 10s CASSETTE, POSSIBLE?

bubsy said:

I'm in the process of putting together a build list & I'm unsure if shimano 10s cassette cogs are interchangable like the 9s 105 cassette's, I like the idea of 11,12,13,14,15,16,18,21,24,27 with a compact crankset, does any body know if I can achieve this. THANKS.

You could make a 11-27 10s shimano, but it would not be the cogs you listed.

11-27: 11,12,13,14,15,17,19,21,24,27 (that what you would get if you follow this recipe)

1. Start of with 12-27 10s shimano cassette.
2. Remove top position 12T and 16T.
3. Replace with 11T and second position 12T (must be 10s cogs)

You cannot mix 9s and 10s cogs together with Shimano.

bubsy said:

I'm in the process of putting together a build list & I'm unsure if shimano 10s cassette cogs are interchangable like the 9s 105 cassette's, I like the idea of 11,12,13,14,15,16,18,21,24,27 with a compact crankset, does any body know if I can achieve this. THANKS.

here are the diagrams of the stock Shimano 10-speed cassettes
DA 7800:
bike.shimano.comEV CS 7800 v2 m56577569830536881.pdfOpen ↗
Ult. 6600:
bike.shimano.comEV CS 6600 v2 m56577569830537975.pdfOpen ↗

Looks like you might be able to do it with the Ultegra with loose up to 18 and then the [21-24-27] on the common carrier from the 12-27, but would probably have to go 17-19-21 on the DA as the (17-18T) or (17-19T) are on a common carrier. (lock ring and spacer are different, for 11T and 12T top gear, I believe)