i have been looking to buy a hybrid bike. I've noticed though that they don't seem to be geared as low as mountain bikes. the ones i've looked at have crankset gears 26/36/48. What i'm wanting to know is if you can change out the smallest ring for a 22 or 24 ?

Depends on the BCD of the crank arm and the tooth range of the front derailleur. Also the rear derailleur needs to have sufficient wrap capacity.

The chainring/chainwheel is the "sprocket." Perhaps you meant changing the chainring on the crank arm.

Also don't assume that a crankset even can have different rings interchanged. Many hybrids (and low cost other bikes) have rivitted or welded assemblies of their rings/spider arms. So often a different ring size requires a different crankset (which might also involve the BB type/size). Andy.

It depends on the make/model of the crank, and make/model of chainring.

I have a Shimano XT crankset on one bike with the 32T swapped for a 36T, and the 44T swapped for a 48T.
I needed to cut down the anti-chain-jam post behind the crankarm to enable it to fit.

You need to not only check the BCD of the chainrings, but also the tab of metal around the bolt hole may also extend toward the center of the crank to a different extent. The original 32T on that crank had a longer tab than the 36T that replaced it. In this case it worked, but the inverse combination of crank and chainring would not.
Here is a thread talking about the issue: https://www.socaltrailriders.org/inde...-issues.15866/

If that bike happens to have a square taper JIS BB there are quite a few cheap triple cranksets available at 42-32-22, some of them are riveted and couldn't be changed but if you struggle with climbing as bad as i do it might be worth losing top speed to get over the hump. the cranks i'm talking about cost less than some single high quality chainrings, so even as a temporary solution it might be worth the money ... this cheap Shimano crank has replaceable rings

26/36/48 actually sounds pretty good to me. I can't seem to find any that aren't 28/38/48. I was successful changing the granny of a Truvativ Elita road triple (52/42/30) to an FSA 24T chainwheel. I changed the middle ring to 39T because the mechanic at my LBS was concerned about the shift from 24 to 42. He needn't have worried, most times that shift is missed and the FD shifts from the 24 to the 52 as quick and as smooth as anything you have ever known. And as far as the wrap capacity of the RD... well lets say that the actual range of gears exceeds the recommended wrap capacity by a huge number of teeth and it has not been a problem. None whatsoever.

The first thing you need to check, as others have noted, is whether your chainrings are individually addressable. If they aren't and your chainrings are bolted together, I have seen 22/32/42 unit triples for sale, and you could do worse at that price range than just swapping out the entire crankset. If you are working with a hybrid in the over $400 MSRP chances are the crankset will be of the quality level where you can change the rings individually. Then, again as others have said, you just need to know the bolt circle diameter you need, and find a maker for a 22T or 24T chainwheel. If possible. For the Truvativ Elita the BCD was 74mm IIRC for the granny, and that meant a 24T was the smallest chainheel possible. That just might be the case in your situation. FWIW.