11-28 Cassette with Shimano GS medium cage derailleur OK?

Over at rec.bicycles.misc someone was asking about a K2 Mach 1.0 road bike on
sale. Looked like a pretty good buy and I noticed the rear cassette is a SRAM
11-28 I assume its either the PG-830 or PG-850 The rear derailleur is a
Sora and they only make that in a GS medium cage version, which Shimano says
is good to 27t. (K2 also does this with a flat=handle road bike) On this
bike the front is a standard Truvativ Triple: 52-42-30 As the manufacturer is
delivering the bike this way, can it be assumed this combination works fine?
And would more high end Shimano GS derailleurs also work fine with an 11-28 ?
I have an Ultegra RD6502 derailleur I want to put on a Giant OCR3 which has
a SRAM 12-26 and I wouldn't mind betting an even lower gear by changing the
cassette to something with a 28. Thanks to all!

rs wrote:

... the rear cassette is a SRAM 11-28... The rear derailleur is a
Sora and they only make that in a GS medium cage version, which Shimano says
is good to 27t. As the manufacturer is
delivering the bike this way, can it be assumed this combination works fine?
And would more high end Shimano GS derailleurs also work fine with an 11-28 ?

Yes and Yes. Shimano's specs are conservative in this respect. Some have
reported using up to 30t cogs with Shimano's road derailers. I've never
used larger than a 28.

--
Dave
dvt at psu dot edu

dvt wrote in :



Yes and Yes. Shimano's specs are conservative in this respect. Some
have reported using up to 30t cogs with Shimano's road derailers. I've
never used larger than a 28.


Not just Shimano - I had a 30t cog with A 9Sp Veloce, which is only rated
to 28.