I am riding a surly ghost grappler with travail ehline durables. Wanted to go with something more pavement oriented. I do gravel roads "sometimes" but planning more "adventures" this coming year. I did get over 3000 miles on this rear tire, front is still ok. One puncture that sealed just fine. Thinking I should just stay with the travail. I was very good on gravel, and the knobs I think do provide a bit of extra protection from glass, etc.

Thanks.

Is there a question, or is this a statement? If a recommendation is sought, I like Panaracer GK semi slicks in 28 to 32 mm width for mixed surface rides. The slicks are also good, both available in narrow to very wide. The semi-knobbies would be real good on gravel, but I do not like them on pavement.
Less dollars and not as durable, the latest Vittoria Zaffiro
pro G is a good tire. I like the control version, but I believe they were discontinued. They mount a bit wider with a higher profile, and have more tread. They are a bit slow rolling, with a cushy ride, ime.

Slicks work well enough on the occasional gravel road. You don't give any idea what type bike this is for. But for up to about 32mm wide tire, I'd recommend Continental GP5000 in one of their half dozen or so different types. I used their tubed version for a long many years. Even the 25mm was adequate for short stretches of gravel.

You don't need knobs at all. Especially if it's only occasional. If you are worried about flats and such, then go tubeless. If blazing speed isn't the thing you ride for, then maybe even run flat inserts might something to try.

I'll second the use of simi slick to slick tread patterns for road and hardpack. One aspect of deep tread/knobs when on the road is that stuff can get trapped and "picked up" inside the tread depth or between the knobs. My Panaracer Paselas in 32mm wide pick up the tiny flecks of rock dust all the time on my touring bike. This trapping of the derbies will let them slowly have the chance to start to cut into the actual tread cap, ending up with tubes getting cut. On a trail or dirt road this is less the problem than if on the road and that derby bit is a shard of metal or chunk of bottle glass.

I have used two examples in how I describe the function of tread on a bicycle tire to my customers. #1 is using my hand. I place it on the counter top, flat against it. I then try to slide it along the surface. Like this.



Then I lift my palm off the surface but maintain fingertip contact and repeat the attempt to slide the hand. I tell my customer to note both that it's easier to move the finger tip only contact than the full hand one. I also tell them to watch my fingers as the cock/slant/lean with the tips wanting to stay put but the palm moving at their other ends. Like this:

I also tell them that if the surface was deformable (snow, mud, sand) my extended fingers would provide more traction as they were able to engage the surface and act like cog teeth digging in.

Method #2 is to ask them about their car's tires, which is about the most many lay riders know about any kind of tire (so car tires MUST be what all tires do)(satire...) I ask them if they drive with snow tires all the time, why if a deeply treaded tire is better in the winter snow/mud they are not used all year? I'll go further and describe car tires as being squeegees running down the road's surface. If wet enough the wall of water that builds up in front of the tire/squeegee, can lift it off the road (hydroplane). So tread grooves provide paths for the water to take to exit from under the contact patch. On the other hand bicycle tires take on a contact patch shape much like sailboat, with a very good water shedding around the contact patch ability, so bike tire tread is of vastly less ability to hydroplane, even if we could ride as fast as a car can go. Andy.

I've been very impressed with GravelKing SS+ 700x30s on my endurance road bike. I was super impressed with them on crushed limestone trail that caught me off guard. I have the GK SS+ 700x38 on another bike and they are great on paved trails but have no gravel time to speak about. I have also been impressed with Continental DoubleFighters 700x38 on paved and crushed limestone but they are a heaver tire that the GK options.

So what size are the tyres you have been using?

Right now I have the ehline durables in 27.5 x 2.5. running them tubeless. I guess I didn't really ask a question. I was wondering if 3000 miles a season on a rear tire on mostly asphalt/roads was worth worrying about. I used to run Marathons on my mtn bike and would get like three seasons or more. But the also sucked on loose gravel. I'm planning on riding more gravel/trail this year but still a lot of asphalt trails/etc.
Not sure how narrow I can go. But the 27.5 seems to be limiting a bit. The ehline and bike were just great on gravel when I did gravel.

Sheldon Brown argues that it is "impossible" for bicycle tires to HYDROPLANE. Jobst Brandt made a similar CASE.

I've listened to so many customers/riders who claimed they did hydroplane, and thus crash. Like the lowered friction of a water (sometimes with car oils mixed in) covered road surface isn't the issue Andy

That's right! There's no question about the role of water as a lubricant. But "Hydroplaning" sounds so much more like "It wasn't my fault!"