mrmb

Never got a flat till recently.

The flat was caused by a tiny rock so it's not a very fine, surgical looking hole.

The outside of the tire looks like it has a small rip (an mm or two long), the inside of the tire has what looks like a tiny hole. The tube has a tiny hole too, not a rip.

These are skinny road tires btw...

What is the general rule as to what to do here? The best thing would obviously be a new tire and tube, but I don't want to replace the tire every time I get a flat if I don't have too....nice tires aint cheap and flats happen. Tubes ARE cheap.

FastJake

Short answer: patch the tube or replace it. Keep the tire.

Sounds like your tire is fine. Tires (used with tubes) do not need to be airtight so as long as the cut doesn't impact the structural integrity of the tire you can keep using it. If the cut is long and the tube bulges out of it, you definitely need to replace the tire. But this is rare in my experience.

dabac

I'd patch the tube for sure. Perhaps even the tire.
Some report having good luck closing small cuts in tubes with superglue
Sometimes grit will find its way through an existing structurally unimportant cut and cause a flat through chafing.

10 Wheels

Patch the tube.

Place a small piece of duct tape over the cut on the inside of the tire.

fietsbob

You Found the offending Puncture creator .. Some times a tiny wire strand is imbedded in the tire and will, re puncture
any Tube you put in until that debris is Removed..

Andy_K 

I have a tube of Shoe Goo that I use to fill in especially big cuts in the tread. If it looks like there was a separation in the tire casing (as seen by the tube bulging before Shoe Goo is applied) I'll also put a patch on the back of the tire.

Jeff Wills

I've had a cut in the tire be small enough to escape notice but big enough to allow the tube to push through and wear on the road, causing a flat 20 mile down the road from the first flat. This has happened to me twice in 30 years of riding, but it happens.

Shoe Goo, duct tape, or a tire boot will allow a tire to work for a while longer, but I usually replace a tire if it's cut that much. Fixing a flat caused by a failed repair just makes me depressed.

79pmooney

I generally put a tire patch over small holes and rips. Keeps the tube in and derbris out. Takes very little time if you are patching the tube anyway. Diligence means finding the tire puncture and cause anyway. If the tire distorts at the cut when inflated and the tire is worth saving (like the rather expensive, wonderful riding but easily cut Vittoria Open Paves) I glue a large patch of dacron sailcloth on the inside with contractor's contact cement or Barge cement. (If you ask nicely, any sailmaker will probably just hand you a decent sized scrap.) I have ridden thousands of miles with large cuts so repaired.

Ben