GS or sgs derailer?

I`m after a rear derailer for my 27 geared Ht, just a little confused as to what rear derailer to get .. GS or SGS, on some sites they have the gs as long cage and sgs as super long cage …on other they have the GS as short cage and sgs as super long cage ..

any ideas please.

For 27 speed you would usually want the SGS which is the longest cage. Only use a shorter one if you will NEVER use big/big or small/small gear combinations as you will probably rip the mech off or lose your chain.

You should never be anywhere near big big small small gears anyway..

You can ride any rear cassette tripple combo on a short cage road mech if you don’t try and ride cross gears, a GS cage will be more than sufficient.

Simon who runs Ultegra short cage on his BLUR LT.

There’s no difference in chain length between 34-24 and 12-46, min and max gearing, it’s just the stuff in the middle you need to take care of.

Write yourself a gear chart and see where your natural crossover gears are.

11-32 cassette on a hardtail = GS, 11-34 cassette on a hardtail = SGS (probably), 11-32 or 11-34 on a FS = SGS (prodably, due to chain growth/shrinkage during travel).