Originally Posted by Arrowana

By converting your bike to 1x, you reduced the range of gearing of your drivetrain. Either your lowest gear isn't as low, your highest gear isn't as high, or both. Depends on the size of chainring you used. If you find yourself wanting a lower gear than the lowest you currently have, you could swap to a smaller chainring, but then your highest gear wouldn't be quite as high. Or you could swap to a wider range cassette where the largest cog is a larger size, and get a lower gear while keeping your higher gear as it currently is. The trade off is there will be a larger gap between each gear, you have a higher chance of one gear feeling too low and the next one feels too high, rather than having a gear that feels just right for the situation.

If you have a Sora 3500 rear derailleur, the largest cog it is designed to handle is 32t. Chances are the largest cog on your cassette is between 28t and 32t. Installing a cassette with a larger cog will give you a lower gear. It might be possible to make the derailleur work with a cassette that has a 34t cog, by turning in the b-tension screw on the derailleur all the way in. If you add something like a Wolf-Tooth RoadLink to the derailleur, it could handle a cassette with a 36t cog. Or you could swap to a MTB derailleur that is actually designed to work with a 36t cog. An example would be a Shimano RD-M593. Or if you want to go with as wide of a range as possible while still being compatible with your new shifters, the RD-M593 with a RoadLink added can potentially work with a cog as large as 42t.