As a newcomer, when do you need to buy bike shorts for a longer ride?
I have worn regular shorts for as long as an hour --I was wondering if I need to buy
bike shorts for longer rides this spring or summer. I weigh 155 lbs. and have a
fairly comfortable male-specific saddle..

For longer rides you'll appreciate either padded shorts or a padded liner to wear under unpadded (or regular) shorts. Hubby switched from denim shorts to bike shorts after only a few months of riding because he disliked the feel of the looser denim shorts rubbing the top of each leg with each pedal stroke. I wear padded liners under unpadded bike pants, or under jeans if I'm out for a short ride around the neighborhood. I tried a short ride once without the padded liner and it was very uncomfortable.

Edit: That said.... you'll know when it's time. If you're not uncomfortable yet, you can wait until you ride a little longer and you start to feel discomfort. I make most of my bike-related purchases in that manner.... when the need arises, I get it. My next purchase will be shoes because I don't like the grease stains on my everyday running shoes.

Although I'll admit to having owned a pair of padded spandex shorts once, almost all the riding I've ever done was while wearing cotton shorts. This includes several extended tours. These days, I do wear cotton briefs under the shorts because they improve comfort. My current favorite riding shorts are "Land's End" brand that I got for almost nothing at Sears. A nice soft khaki without a lot of extra pockets. I also weigh 150-5 and ride a Brook's saddle. I also wear loose shirts. A silk/linen blend bought on sale is my favorite. I think Spandex is partly explained by the need many people have to feel enclosed, packaged. Just my humble opinion, of course.

There are many right ways to go.
When I ride more than 30 miles, I would not think of riding without padded lycra shorts or bibs, especially in warm or hot weather. The longer the ride and the hotter the weather, the better the pad needs to be. The padding is not so much for cushioning as for controlling moisture and abrasion. I would also stay away from gel.

Shorts are not that expensive that I would ever ride without them. Just buy a pair and try them. You won't go back.

I should say about 2 years beforehand- Just so you can run them in.

Someday they won't even look dorky to you.
Really, I can't imagine riding in regular shorts. Even on my 8+ mile commute I suit up.
I've done it in tennis shorts, but it sure feels better in bike clothes.

One thing: Skip shorts. Just man up right now, admit you cycle and spring for bibs. Really.. Seems weird, but if you're out over an hour you'll be happy you did.

I think Spandex (Lycra, actually) is largely explained by the fact it's highly functional. A good pair of bike shorts (or better yet, bibs) is very comfortable, wicks moisture well, and prevents chafing, especially on longer rides.

I can't +1 this enough. I shied away from bibs for two years, and finally, when I found a pair that fit and was on sale, took the plunge. I almost NEVER ride without them now, even for really quick trips (except fo the grocery store run). Bibs are the best thing since sliced bread.

Bibs are great...I'm not sure about sliced bread though...

I don't do bibs. Yes - they are comfortable, but all that undressing behind a bush when nature calls is just too much hassle.

why are bike shorts better than my running shorts? is it the padding and/or spandex?
And why are bibs better than bike shorts?

+1 to cccorlew and DigitalGee. I'm not sure I can explain it either.

I rode with bike shorts years ago, but when I returned as a 50+ I was perfectly comfortable up to a couple of hours with normal shorts. HOWEVER, when I did switch back I got both bibs and bike shorts. Now, I'll ride the trainer with the bike shorts but if I'm going outside I wear the bibs.

You probably won't miss them if you never get them, but trust us, the bibs are more comfortable.

They don't roll down over your spare tire, if you have one.

At 155lbs thats probably not one of the OPs bigger concerns, but thats true too.

At 150 lbs and that midriff is thickening. One of the advantages of Bibbs is no tight elasic holding the Bulge in. Might be a blessing to some but a tight waist does get uncomfortable after a while.

Bibs! Don't leave home without them!

Ride On!
-Spoke

Here we go.

Bike shorts (or bibs) are tight to you don't get any friction where you don't want it, if you know what I mean and i think you do. They fit like a second skin, as opposed to having something just lightly tear at some tender spot for hours and hours until you think waterboarding sounds like relief.
The padding isn't padding so much as moisture control. If you've done Levi jeans on a really hot day you know how friction and moisture can add up to no fun.

Bib's just stay in place better. There's that "man bra" thing that can be a plus, but mostly it' stht they don't slide at all. I never am aware of the straps. They also can come up your back better when you're all bent over.

BIBS. Get 'em.

Both.

No elastic waistband.

+1 for bibs, once I tried them I cannot go back to shorts

Like most of the others I agree that bibs are much more comfortable but they have one draw brack in my opinion. Since they cover more of your body they are hotter than shorts. Where the OP lives that should not be a problem most of the year.

Oddly, I don't find bibs warmer. Just more comfortable. But that's just me.

+1 on bike shorts, bibs in particular. The pros don't wear them because of how they look in them, it's because of how they FUNCTION. More comfort and more aero. Don't worry about how you look, just do it. You'll be glad you did.

Just buy some padded underwear from REI or Rivendell and some good shorts with pockets. I have ridden all my life without going with spandex including touring and centuries. I never feel comfortable around adults wearing skin tight spandex with cartoon characters on their shirts. I found some nice quick drying shorts at Travelsmith

I've pretty much worn cycling shorts (the tight fit kind)for 4 decades (first ones were merino wool)
I tried the baggy shorts with the chamois but found the compresson on the thigh muscles from the nylon.spandex seemed to afford less fatigue.
That said: Aero Tech designs offers some fantastic cycling shorts (U.S. made at their Pa.Plant)at reasonable prices.
If you go with road shorts go with the 8 panel. They cost a bit more but imho are well worth the cost.