Mix and match drivetrain....helping hand please:)

[Liam2324]

Hiya guys, basically I want to change my cassette from a 25 to a 28 (the Scottish hills are wearing me down. At the moment there's a 105 crankset with a sram rival (short cage) derailleur, sram 11-25 cassette and sram shifters (don't ask).....I managed to get a ultegra 11-28 cassette for cheap but tried fitting it but it's incompatible with the derailleur as it rubs....if I were going to buy a new derailleur would it have to be a medium or long cage? Shimano or sram? If the ultegra cassette was fitted. and also if it was to have shimano drivetrain would I need to change the shifters?

Any help at all would be appreciated I'm pretty new to the world of biking and don't really want to go buying bits and pieces when they might not be even compatible.....

Cheers

 

[Milkfloat]

Silly question - did you adjust the 'B Limit' screw to fit the 28?

http://www.artscyclery.com/learningcenter/sramrearderailleurs.html

 

[Will Spin]

Silly question - did you adjust the 'B Limit' screw to fit the 28?

http://www.artscyclery.com/learningcenter/sramrearderailleurs.html

...and check the chain length, it might need to be a bit longer to accommodate the larger cassette.

 

[Jenkins]

SRAM shifters = SRAM derailleur. You'll need a medium cage with the 28 cassette.

 

[Smokin Joe]

SRAM shifters = SRAM derailleur. You'll need a medium cage with the 28 cassette.

A short cage will easily cope with a 28t sprocket. As suggested, it is the 'B' screw that needs a tweek plus maybe an extra link.