OK . . . first of all . . . welcome to the wonderful world of bike related ass problems!
Getting a good pair of bike shorts helps a lot with butt discomfort and are a good idea to try out for a variety of reasons . . . but if you're getting sore from 30 minute rides, I have a few other recommendations first:
Impacts:
- You don't have to be a pro racer or anything handling wise . . . but it's important to learn to lift your butt a couple millimeters off the saddle when you're going over bumps. If you don't do this (and stay firmly seated) all the impact goes straight to your rear (which sucks) . . . but more importantly, it puts a lot of pressure and stress on your rear wheel and will lead to premature spoke failure (which sucks more because it costs money!)
- Tire inflation! OMG, people are often clueless about this - the number of people I know who just fill up to the max rating. Ugh. The inflation in your tire really matters - overinflated hurts because it transmits way too much shock to your butt (underinflation sucks because you'll get pinch flats so don't do that either). It should be determined by your weight and tire size. If you're light, you're going to want a lot less inflation than someone who is heavy. If you ride big tires then you can inflate even less still. Get a floor pump with an accurate guage, and use a tire pressure calculator to figure out exactly what you need:
https://www.cycleschinook.com/tire-pressure-calculator/Bike fit:
- Are you sitting in an extremely upright position? The position that you ride on a bike is a balance between hands, feet, and ass. The more upright you sit, the more pressure on your ass. Sitting upright puts your body in a less efficient position to put power on the pedals, which means you get tired more quickly, and tends to lead to less pressure going into the pedals . . . besides making you slower, this means that you're going to be putting even more weight on the butt because you're not taking it away with your legs/feet.
- Next thing that goes hand in hand with the above info is bike fit. First lets make sure that you've got roughly the right distance from the saddle to the pedals. Get someone to hold you upright on the bike (or grab a wall). Unclip your feet and put your heel on both your pedals. Spin the pedals around backwards. Your heels should be just about coming off the pedals at the fullest extension. If they're not doing this, your saddle is too low and needs to be raised. If you are losing contact with the pedals at the furthest extension then the saddle is too high and needs to come down. Saddle in the wrong spot will cause serious ass soreness! If you're reaching, then you're grinding your undercarriage every time you pedal. If you're too short, then you're going to tire very quickly and will be putting more pressure on the butt for that reason. So make sure this is right!
- OK, bike fit the moderately more advanced class! Let's start with the fore/aft position of the bike saddle and the reach to the handlebars. Reach to handlebars should always be changed by getting a new stem . . . but that's expensive and we're all cheap-ass folks, right? It's a lot easier to slide the saddle forward on the rails to make up for handlebars that are too far forward. The problem with doing this though, is that it tends to put the rider in a straighter leg position. Stand up right now and do a squat. Notice that as you go down into the squat your ass pushes way back to counterbalance your upper body weight? When you push the saddle too far forward your body can't do this - and it ends up putting extra stress into your hands. So then people will often tilt the saddle nose up in order to compensate for the 'sliding forward' feel. This is really bad because it jams the hard saddle nose into your crotch with full body weight coming down on it. Ugh. Start out by making sure that your saddle is level with the ground and that it doesn't feel like you're sliding or reaching too far forward.
- Positioning (maybe should have led with this) make sure you're sitting on the widest part of your saddle. All bike saddles narrow at the front. If you're scooted too far forwards on the saddle, it's gonna hurt your nads and butt. Scoot back a bit if you're doing this!
Bike saddle:
- Big, soft saddles hurt when you ride on them for long periods of time. A saddle needs to be hard enough to provide support, and narrow enough that it doesn't cause chafing. That said, everybody's butts are different and some people need a wider or narrower saddle. General wisdom is to measure your ischial tuberosities and then get something a cm or two wider so that you're sitting on these butt bones.
- The shape of a bike saddle matters a lot and is very personal preference. There are saddles that are rounded or flat along the top, there are saddles with a dip in the middle, there are pear shaped saddles, long saddles, short saddles . . . you have to try out a bunch to find one that works OK. Unfortunately, if you're like me all saddles feel comfy for the first 60 kms or so . . . so try to find some friends into cycling, or a store with a good return policy because some experimentation will likely be required here.
- Cutouts in bike saddles rock, and help my 'nads hurt less. Give 'em a try, bigger the hole the better.
Bike shorts:
- This is a very personal preference thing. They have to fit your body, so it's going to be hard to recommend without seeing a pic of your butt. (Kidding! Please don't post a pic of your butt.) Look for something that fits tight enough that you don't see any wrinkles in the material (this is not a place to go baggy) and something with rubber grips at the end of your legs (without grips you may find that the legs of the shorts ride up and then cause chafing). Although they feel really weird at first, I'm a huge fan of bib shorts over regular shorts . . . the bib ends up being way the hell more comfortable, but they're usually more expensive. Also, when you're sitting on your bike you shouldn't feel any stitching digging into your 'nads. NO UNDERWEAR UNDER BIKE SHORTS - non negotiable.
The average person should be able to do an hour long ride on a bike without bike shorts and without feeling any real lasting discomfort in a pair of athletic shorts. By adding in a pair of bike shorts that should keep you comfortable for 5-6 hours. You can get away with something that's OK on shorter rides but the longer you're out there for, the pickier you'll find yourself becoming about saddle, shorts, and position on the bike. Little problems tend to magnify into TERRIBLE HORRIBLE THINGS if ignored.