Change to larger cassette - chain question

Hi all - I am currently riding a 11-25T 10 speed (old bike) cassette and thinking of changing my cassette to 28T. Based on calculations I am 1 chain link short.

Has anyone had any experieince running a chain 1 link short? Do I need to change my chain if I wanted to use the 28T? Would it be a big deal to not change the chain? I have several waxed up chains for my existing set up that I would hate to discard!

Thanks all

I’m currently running a link short as I changed rings and went from a 48/35 to a 50/37. It’s wasn’t worth throwing a good (non worn) chain out for me and only notice it feels “tight” when in the big ring and largest cog.

I went from 11-28 to 11-32 and used the old chain until it wore out. I just made sure not to go big-big and all was good. On the workbench, I did “attempt” the big big combo and it was a no go situation.

Should be ok, but might depend on how tight your current chain is. I’ve swapped chainrings (50 to 52) and calculated one link short, but its working fine without that extra link. Even the big-big combo.

I just switched out an 11-34 for an 11-40 with a 46/30 at the front for a bikepacking trip with some sustained climbs. Have left the chain the same length, I would not go big-big but big-9th gear is fine and I’d be cross chaining after that. If you have Di2 you can block undesirable gearing ratios in the app I believe.

I’d put on a new chain as its unlikely your old chain will mesh correctly with your new cassette, and if as likely it doesn’t mesh it’ll wear out your new cassette prematurely. Its likely that the chain will be to taught also at best causing it to snap at worst pulling the derailleur into the cassette. I’ve ran a shortened chain as a ‘get me home fix’ and you’ll probably find you need to stay in harder gears and avoid the 28t.