Ideal spread for a 9sp 12-25 cassette?

[Chrisz]

OK, after thrashing around (and struggling on hills) with a 9 speed 12-23 setup for years, I have taken the plunge and changed my cassette around slightly.

I have worked out that while I need and use the 12 cog I need a bigger cog for hills (I'm just too heavy for the 23 bottom ). Thus I have added a 25 to my cassette.

What I would now like to know is what is the ideal spread for the cogs i.e. with the least jump in teeth between cogs to give me an even spread through the gears?

TIA

PS Please be aware that losing the 12 is not an option as I do use it on descents quite regularly.

 

[Ian H]

If you're putting your own together, I'd go straight through to 16, then 18/20/22/25. Or you could go straight through to 17, then 19/22/25, but you'd notice the 19-22 jump if you spend much time around those ratios.