Numbnuts question

[Dec66]

No, it's not about saddles, despite the title.

My B'Twin's current rear cassette is 8-speed, 12-25T. I think it's due for a change, and I'm thinking of going 11-28T, still 8-speed.

The question is; are those three extra teeth likely to result in me needing a new, longer cage? I think not, but I'm a bit dim in such matters.

 

[fossyant]

Road bike I assume. Do you know the model of the rear mech ? You will need a new chain, with an extra few links in. It should be OK.

 

[Dec66]

Microshift, but Decathlon don't specify a model.

Edit: looks like an RD-R42, and the long cage version at that.

 

[shouldbeinbed]

Road bike I assume. Do you know the model of the rear mech ? You will need a new chain, with an extra few links in. It should be OK.

+1.

A general rule of thumb is 2 teeth = 1 link

 

[Dec66]

Thanks chaps, I'm going to replace the chain anyway so I'll be sure to get a longer one.

 

[doog]

Might have to adjust the B screw

 

[Dec66]

A spot of research reveals that Decathlon sell a self-branded 12-33T cassette (actually a Sunrace) which one of the reviewers used as a straight swap on his Triban 500SE with no derailleur adjustment needed.

Shimano and SRAM compatible, so I'll probably go and get a Shimano HG50 with 11-28t on it.

Cheers all