rachel120

The bike was bought new in early July. Both tubes were bought at the same time, late July/early August. The rear tire did have a slow leak I didn't catch for a few days, but that was 5-6 months ago, and the patch has been holding. Since then, both tires have stayed nearly matching PSI, variance less than 5 pounds. The sidewall on the tires says to inflate to 50 PSI. It's a commuter bike, entire commute on asphalt, 6 miles total per day.

February I didn't ride my bike. I've ridden it four days in March, and I was a bad girl and didn't check pressure until today, 35 PSI in both. While inflating the tires I noticed some uneven wear, with the rear tire showing more wear than the front.

Is it time to replace the tire? What would be causing this uneven wear? Would the cause affect a new tire if it's time to replace it?

Picture of rear tire first, front tire for comparison second.

dsbrantjr

Bike tires always wear faster in the middle of the tread because that is where it spends most of its time in contact with the road. Rear tires tend to wear faster because they typically have a heavier load than the front ones. When I change tires I generally discard the more-worn rear one and put the front tire on the rear; the new tire goes up front.

jwh20

The rear tire almost always wears out faster. It carries a higher load most of the time. But yes, that rear tire is getting worn out. Since you ride on the road, at least that what you seem to indicate, perhaps a different style of tire will suit you better. These are trail/dirt tires.

LKA 

Normal wear.
Generally speaking, rears wear out faster then fronts. That rear tire looks like it still has a little life left, maybe change it when the tread down the middle is completely gone and has a bald look to it.
The above is offered in good faith, & w/o prejudice.
If I am found to be incorrect, I guarantee you someone here will point it out.

Good luck!

ThermionicScott 

Rear tires also wear faster because they are the drive wheel, so there is some scuffing against the ground.

It's not because you're a "bad girl."

fietsbob

Unlike a FIM Racing Motorcycle, you don't spend much time in knee pad scuffing high speed corners

Retro Grouch 

If it was my bike I wouldn't be in a hurry to buy new tires, but I'd be thinking about it. Front tires normally outlive rear tires by at least 2 to 1. Some riders buy tires 3 at a time and get 3 more when the second rear tire wears out.

Your back tire will tell you when it's time. It does that by puncturing more often. When you get your second flat, that's the usual signal that it's time. Since you commute entirely on asphalt, I'd get a slick tires. They'll be quieter, smoother riding and handle better in all conditions, including rain.

rachel120

Thanks everyone. I will look into different tread tires, but would I need new rims too if I get road tires? Sorry for the second question. But at least I know there's not a mechanical issue nor is there a need to rush out and buy one tomorrow, so I've got time to look at options.

jack002

No, no need for new rims, get smooth tires with the same dimensions as the ones you have. they'll go right on your current rims

I have seen rear tires wear almost twice as fast as front. Take them and reverse them when you see an offset of wear and if you time it right they'll both be worn out together.

hochflynn

No need for new rims. You just need to get a similar sized tire, but as others have recommended better suited for asphalt (slick/road or at least not nearly as knobby).

jwh20

You'll probably find pedaling is easier also. The dirt tires don't roll as easily on paved surfaces as slick(er) ones. They will last longer too since there is more tread on the road.

canklecat

Switch to pavement tires as soon as you can manage it. You'll be pleasantly surprised how much more easily the bike rolls and feels on turns. All that tread wear is a good indicator of how much energy is being expended on friction just moving that squiggly tread on pavement.

Nashbar, Jenson USA, Bike Tires Direct and others routinely offer good pavement tires to replace knobby mountain bike tires for less than $10 each.

NJgreyhead

OP, yes, get road tires for your road riding. You'll roll better.

And when it comes time to replace them, do like this guy says:

You always want your best tire on the front - less chance of flatting and loss of steering control.

TimothyH

With all due respect, when you get your second flat is is way past time to replace the tire.

Late for school or work, changing or patching tubes in the rain... Who has time for that?

Reliability is paramount for a commuter bike and that tire is almost done. I'd replace the tire proactively (with a slick) before the spring riding season and be done with it.




-Tim-

ThermionicScott 

Replacing a tire after two flats total, am I reading you right?

woodcraft

Wouldn't the slick be pretty much the same tire without the knobs?

In that case, the tire is almost worn down to new condition.

rachel120

I'll admit to being tired and may be misreading your post, but it sounds like you are saying I should replace the tire every time my tube gets an air leak. That sounds really odd. I'm not using tubeless tires.

SquidPuppet

Whaaaaaaaaaaaaaaaat?

dabac

Ignoring the spread between different makes & models - no.


A "rolling resistance"-optimized knobbly tire will have the area between the knobs and ridges only slightly thicker than the sidewalls while a rolling resistance optimized slick tire will be something like 2-3 times as thick.
A puncture protected/durability prioritized slick tire will be thicker still.

dabac

Maybe if you're in goathead country, or some other place where the main reason for flats is fairly well calibrated in size.


As a general recommendation, I beg to differ.
The number of flats I've had that has made me think "2-3 mm more of rubber would have saved me from that" are VERY easily counted.
And I've been doing 6000+ miles/year for ages.


My main identifiable reasons for flatting is either the crushed up stone flakes used instead of sand in winters, or those sneaky pieces of steel wire coming off worn truck tires.
It'd take a HUGE chunk of rubber to provide fully reliable protection against those.
Last stone chip could have been mistaken for an arrowhead and would have gone through 12 mm at "ideal" alignment.
Last wire flat would have been able to pierce an 8 mm thick tread section.

fietsbob

And dont worry your new smooth tread tire will also start out round, but over time the rear will wear to appear a flatter edge as well..

It's normal , you ride straight up, perpendicular to the street, most of the time..

rachel120

Thanks. Yeah, I just wanted to make sure it was normal wear and not a sign that something was wrong.

I guess I should have thought about the load bearing difference of my fat butt being almost on top of the back tire. Sometimes I totally fail Physics 101, lol.

dabac

I think the rear wheel providing driving power is a bigger reason for wear than load as such. Fronts last longer b/c the time spent braking is a tiny fraction of the time spent driving.

79pmooney

Rachel, there's no need to panic. Your rear tire is good for quite a few more miles. But you could do yourself a favor and buy two road tires of that size. Then either splurge and put both on or put your current front in back and put the new one on the front. (When the rear goes, the newish road front goes in back and your other new road tire goes in front.)

If you do the first option you won't see a huge change. Replace both and the bike will feel quite different and it will be fun! (The rear tire is the key to a better feeling ride.)

Again, what you have now is perfectly safe and ridable. New road specific tires with much smoother thread will however be a big step up for a nicer ride.

Now a question: Do you know how to change a tire and tube? Have you done it yet? Flats happen. Flats have been happening this past 130 years and will for probably the next 100. You will see one. Being prepared is the difference between a not so fun, dirty hands ride and possible an epic experience you never want to see again this lifetime. Changing tires and tubes isn't hard - if you have the right tools and know what you are doing. A bike shop can show you how. If you have them swap the tires, ask them to do it in front of you. But beware. Watching someone else helps a lot but you are not there until you do it yourself. If you have a bike coop nearby, I highly recommend riding there and taking the tire off and putting it back on yourself with them around to show you the tricks.

Rachel, I've been following your journey into cycling since you first came on board here and refrained from saying anything to not scare you off. You're a trooper. Troopers fix their own tires. It gives them a big step more freedom. (And if you already know and can do this stuff, congratulations!)

Ben

rachel120

Awwww!

Yeah, I can swap them out on my own. Both the OEM tubes failed pretty quick. I also finally figured out patching when the rear replacement tube got punctured, the OEM tubes had such epic stress failures I couldn't patch them. My only issue is I'm slow at getting the rear tire perfectly aligned when putting it back on. It doesn't drop in neatly, the U it fits into is actually sideways, not up and down, and too far forward leaves the actual rubber too close to the frame, too far back and the brakes don't sit right. Even taking a Sharpie to mark the right place didn't mark a perfect alignment.