[MrFlippant]

Huh. I actually LIKE the grip level of sport track. Many tires hook up quite nicely on Sport, and if you WANT drifting action, you can still get it, unlike Ninco where you could run bare plastic wheels and get good grip.

but seriously, the softer the tire, the better the grip. The oil tip is a good one. WD-40 is a quick version of that. Or some Slot.it F22 or P6, or NSR tires. There are also many urethane brands to try, Yellow Dog being the most readily available to most people, and of course silicone. I have only one set of tires I wasn't able to improve with oil that I thought would, and that was a set of tires on an AutoArt car. They don't respond to anything.
Remember, if those replacement tires were made years ago, they might also be a bit hard, relatively speaking. The oil/WD-40 trick should do wonders for them.

 

[MrFlippant]

Well, the oil is meant to soak into the rubber, not provide grip itself, but I'm sure you know that.
The point is to make the rubber softer, just like racing tires are MUCH softer than regular road tires. The more grip you want in your car, the softer the rubber tends to be, and the faster they wear out, and the more expensive they are. Not surprisingly, that's a lot like how slot car tires are. ;-)
NSR Super/ultragrips are CRAZY good tires with grip to spare. They are also very soft, and perform best when cleaned with lighter fluid before a race, and treated with oil after the race. The same tricks don't work on all rubbers, but most rubbers (not urethane or silicone) respond to some kind of oil. WD-40 is a thin but fast penetrating oil. Fast results, but also short life. Other oils can take longer to penetrate, but also last longer. Some oils will cause some rubber to expand too much or even completely break down. I know people have used oil of wintergreen, and people have used suntan/screen lotion (SPF50+ apparently). I bet there are some that use baby oil. LOL. Heck, I've even seen people spray the track with WD-40 in one spot so that as cars pass through, the tires take on a little oil, and gain grip as they run. Crazy, I know, but true.
Anyway, don't be afraid to experiment. Worst case is the tires wear out too fast or it doesn't work at all, and you replace them with something else.

 

[MrFlippant]

I agree. My perfect track would be Sport surface and Ninco connections.
I personally like the option of more or less grip depending on tires (Sport), rather than always tons of grip because of the surface (Ninco).
Yes, there ARE solutions for good running on sport. We've given them. They are:
1) treat the tires to soften them (only works with rubber, not silicone or urethane)
2) replace the tires with grippier ones (silicone, urethane, NSR, etc)

You get the amount of grip you want. Simples.

Just take the sage advice of those who know from experience... no matter what kind of tyre you choose to change to or stick with... stick with it. If you go silicone, it's best to run only silicone. If you go with Urethane, best to stick to mostly urethane. If you stick with rubber, then only replace with other rubber. Rubber and urethane are ok together, but if you run silicone and rubber on the same track, neither will ever get their full level of grip. If you run only rubber for a while, don't put silicone tires to the track, or you'll be at square one with the rubber tires.

At this point, I wish I hadn't ever used silicone, but it's not that big of a deal. I use all kinds of tires on my track. Treated and cleaned NSR tires have CRAZY grip on sport track. My cars literally jump out of the slot there's so much grip. Well trued and polished urethane tires are also great, as are nice clean silicone tires.

Whatever your track, there will be good tires for it, and bad tires for it. Whatever tires you choose, there will be things you need to know about tire cleaning and prepping, and track cleaning/prepping/maintenance. People can argue "best" until the cows come home. What YOU like is what's important. Or, if you begin racing with a club or group, set up your track to be the same so you can test/practice on a like surface.

 

[MrFlippant]

just use a very high grit (1000+) sandpaper, or even wet sand.