Hi!
I'm about to purchase a new fork and have been looking online for an explanation of the sizes. I know that I have a 26" 1 1/8 setup, but I don't understand the difference between a fork that is sized 230/65mm or 190/65mm. I'm sorry for the dumb question, but I can't find the answer anywhere.
Thanks!

Is your headset threadless or threaded? The fork's steerer must be a matching type. I assume the 230 and 190 numbers refer to the steerer length in mm and the 65 mm is the rake.

Thanks, yeah its threadless. I think its referring to the steerer length as well. Thanks for the help!

Usually there's only one choice for a threadless fork - long, maybe 300-400mm - and the installer is responsible for cutting the steerer to length. When I see numbers like 230/65 for a fork, it would be for a threaded headset, and the 65 means there's 65mm of threading at the top of a 230mm length steerer.

It's not rake. 65mm is too much rake for a normal bike. Rake is almost always between 40 and 50 mm.

Also,
There are long blade suspension corrected forks.. and those for frames
that were never made to take a suspension fork.

go down to the bike shops and bring your bike, they can see your situation.

Unless these are used forks and have been cut to the advertised lengths. If they are threaded forks, the OP can't use them anyway.

That's typical for 700c forks for road bikes. These are for 26" (ISO 559 I trust) wheels and I further assume MTB geometry.

Maybe the 65 mm is the travel if it's a suspension fork. How about a link to the brand and we could look up the specs from the MFR? 230 or 190 sound right for steerer tube lengths, but I'm at a loss why a new threadless fork would have more than one option of steerer tube length since the installer will nearly always cut the tube to length. I fear that the OP is looking at threaded forks.

65mm could be right for MTB rake, after all. I just looked at an SR suspension fork specified as a 255/130 in the Niagara Cycle catalog that had a 255 length steerer with 130 mm offset (rake) and selectable 100/80 mm of travel. Best look at the manufacturer page for the real information and not trust us internet pontificators.