Cassette part# & spec for 2015 Giant Advance SL 1

[Akalank]

Hi, I'm looking to replace a worn out cassette of my 2015 Giant Advance SL 1 road bike with new one with the same style/part#.
I couldn't find the correct style / part# on the web. (I think later versions of the same model (Advance SL 1) use different casstte). Can some one help out?
Thanks.

[Duck!]

Which series of bike, Defy, TCR or Propel? All have Advanced SL frame variants, and componentry changes across the ranges to suit their intended purpose.

A quick dig through the Giant bike archive shows that for 2015 the Defy Adv, SL1 had a Shimano Ultegra 11-sp. cassette, CS-6800 in size 11-28, while both the TCR and Propel used a Shimano Dura-Ace CS-9000 in 11-25 size. Neither the 6800 nor the 9000-series cassettes are available any more, being discontinued when the second generation 11-sp. R8000 and R9100 groups replaced them. There are some differences in the size ranges offered, and construction methods, but these do not affect compatibility in any way.

[Akalank]

Thank you Duck . Yes, it's a 2015 Defy Advance SL 1 .
The Dura-Ace R9100 series appear to be too pricey for my budget. Probably harder material for bigger sprockets.
So I'm considering Shimano Ultegra CS-R8000 . But instead of the current 11-28T, I'd like to use 11-32T for even slower gear ratio for the steeper climbs. Would that require any adjustment elsewhere (rear derailleur )?
This is the first time I'll be changing the cassette as a DIY. Hence the question.
Thank you.

[bychosis]

Have a look at the rear derailleur and find the model number. Then look up the 'capacity' for that derailleur.

[Duck!]

Thank you Duck . Yes, it's a 2015 Defy Advance SL 1 .
The Dura-Ace R9100 series appear to be too pricey for my budget. Probably harder material for bigger sprockets.
So I'm considering Shimano Ultegra CS-R8000 . But instead of the current 11-28T, I'd like to use 11-32T for even slower gear ratio for the steeper climbs. Would that require any adjustment elsewhere (rear derailleur )?
This is the first time I'll be changing the cassette as a DIY. Hence the question.
Thank you.

The R8000 is the direct equivalent spec to what you have. If the cassette is worn out, you will need to replace the chain as well, as the old one will definitely be toast, unless it's a new one and putting it on the old cassette is how you discovered the cassette is worn.....

The 11-32 cassette will fit with your existing derailleur, but is pushing its capacity limit. 11-30 will be a more conservative option which will still give you a lower gear than what you currently have.

[Akalank]

Thanks Duck for the detailed reply. So I'll go for R8000 11-30 instead. Chain has already been replaced. This will be my first DIY project on the cassette. Thanks again.

[CmdrBiggles]

Looking at the derailleur from the opposite side of wheel, the maximum teeth handled by the rear derailleur might be printed somwhere on the back of sides of its parallelogram, like SRAM does e.g. 36T.

DuraAce is hideously priced for what it is.