More Teeth

Raam

Currently I have a 9 speed 12-25 cassette. However that ain't really enough for getting up the steep hills. I end up grinding rather than spinning. Would there be any issue changing to a 9 speed 12-27 one of these? http://www.chainreactioncycles.com/Models.aspx?ModelID=1094

Morgan

No that should be fine - not sure how big a difference two teeth at the back would make though. If you need lower gearing you could consider a smaller chainring too.

Raam

some dude I met on the way home yesterday reckoned it would make a difference. I think he races for the Irish paralympic team. Also said that it gives a better advantage than getting a smaller chainring on it's own. I think I'll go for more teeth at the back first and then if I still need more, go for your suggestion

Trojan

You could even go as far as 12-30 if it exists, depends on your rear derailleur.

Afaik it should go up to 30 (check with Sheldon). That'd definitely help you out