I just bought a used mountain bike with slicks primarily for commuting. I have no idea how tell if the tires need replacing as I have never had slicks before, I have only ever had "knobby" tires. My boss commented today that my tires are bald, to which I replied I thought they were supposed to look like that because they are slicks. OBV I'm a super newb! Can you guys help me determine if I need new tires? Thanks!

They look fine to me. They're supposed to be smooth with more shallow siping. When the "V" in the center starts to disappear, then theyRe getting bald.

No.

Thanks! I thought the same but my boss had me second guessing myself. Thought it best to verify.

Here's a picture of a similar tire brand new.

Looking at that center seam, I'd have to think you have less than 500 miles on that tire, although the front does wear slower than the rear. You have a couple thousand miles left to go.

I'd ride those until that center tread chevron goes away, or you start getting excessive flats, or both.

Many "road" tires start with a lot less tread than that, or some are perfectly smooth. For example, look at the "thickslick tires".

I'm still hoping to grind some tires down until either I see threads, or the tread changes color. But, I seem to give up on the tires before that point.

these are the actual tires new



Like I said, I thought they were ok, that is, until my boss said something and followed it up with "I used to bike." Thanks for the feedback. Much appreciated.

Thanks for the detailed response! The numbers give me a general idea of their condition. My thought was if I can still see the centre seam then they are in fairly good shape.

As long as that seam is prominent, then they are like new.
As long as you can see quite a bit of the center chevrons, then they are in pretty good shape.

I run "Semi-Slick" tires on my mountain bike and everyone keeps saying my tires look bald when they are actually new tires...........

They look nearly new.

Run them 'til the cords are showing or you start getting more flats than usual, which should be many, many miles from now for either!

^^^This, except I've never gotten more flats the more the tire was worn. My theory is with worn tread rubber, it may be slightly easier to puncture but there's lies likelihood of a small sharp shard staying embedded in the thinner rubber for many rotations and working it's way through the cords and tube.

Your boss is totally clueless, when it comes to bicycle tires................ I'd classify your tires as almost new!

Maybe if your boss still "biked", he'd know something about bike tires.

I'd say that, in the normal course of things, you'll probably change bosses before it becomes necessary to replace those tires.

Perhaps the boss is one of those people that thinks all bicycle tires should be knobbies.

Those still have tread and aren't slicks. They're also nearly new.

This is a worn-out tire:


Note the frayed casing cord showing through holes in the rubber and diagonal lines where it's getting close after 5257 miles. Mountain bike tires with thicker and harder rubber should last longer, although without a puncture protection layer you may find the rate of flats unacceptable before the tires are worn out so you replace them sooner.

At that point throw out the rear tire (it goes first because it delivers the drive force and has ~50% more weight on it), move the front to the rear, and put a new one on the front where a flat is much more likely to lead to a crash.

Tread doesn't improve traction on road - that comes entirely from the tire's compliance with the pavement. It doesn't help in wet weather either with hydroplaning speed in MPH 10.35 sqrt(p) with pressure in psi. 10.35 * sqrt(50) = 73 MPH, 10.35 * sqrt(30) = 57 MPH, etc.

Road tires only have tread because the market expects it from car tires where speed and inflation pressure makes hydroplaning a real problem and tread moves water shallower than it.

In fact, tread on-road can be counter-productive because it's more likely to squirm and upset things when you're cornering.

+1.

Replace the boss . . . then think about replacing the tire.