FLvector

Have you ever had a flat front tire going at speed, possibly on a decent? I'm not talking about a slow leak where you have time to stop, but a sudden flat or blowout.

redlude97

Yes, on an almost new tire. Like I said, I personally think the increase risk is overblown. The same tire you don't trust on the front was just there serving you well for hundreds of miles before. Tires can get flats when new or old, and IME the increase as tires wear isn't dramatic until the cords start showing. Most tires have some type of embedded liner such as vectran to prevent flats which doesn't wear down. If you never run your tires to that point then the increased risk is relatively minor

FLvector

If it was on an almost new tire, then it obviously wasn't related to normal wear. Any tire can flat if it runs over a sharp object - this discussion is about flats related to normal wear. You must have been very lucky to not be going into a hard corner when your front flatted, since its very difficult to control in this situation.

I had very few front flats since I never let the front tire get to the point it is squared off. The rear tire will typically square off long before it starts showing threads. This is usually when any embedded debris that goes undetected slowly finds it's way deeper, then eventually penetrates the tube. I try to inspect the tire for embedded glass or debris, deflate the tire, then dig it out if I see it. If the rear tire flats, you have much more control to allow you to come to a safe stop.

DXchulo

It depends on how well your front tire is holding up. My tires do tend to wear very slowly on the front when it comes to tread life. However, there usually are a few cuts that show up. I don't expect the tire to spontaneously explode, but in my mind there is always that slightly higher risk that debris will work its way in a cut and cause a flat. I do a lot of descending and a flat front tire is the last thing I want. I've had it happen and it's scary. (I was lucky to be on a straight section where the grade was easing up.)

If there weren't any cuts I could see myself simply replacing the rear to save a little time.

redlude97

Thats my point. This is overblown IMO. If you run a tire with flat protection and don't let debris accumulate(I deflate and check my tires regularly too) punctures due to "normal wear" are very rare. Obviously a newer tire with more rubber of the same type is less likely to puncture, but are we talking about the difference between an increase from a 0.5% chance to 1% chance, or 0.5% to 10% chance of puncturing. I think the former.

FLvector

I strongly agree with the bolded statement above, but no clue on where you're getting your stats (%) from. From my own experience and those that I ride with in groups, I'd guestimate that >80% of flats occur on the rear tire. And its rarely on a new tire, rather one that's nearing the end of life.

redlude97

Rear tires flat more often because they have significantly more weight over them, not because they are more worn. Now is it rarely on a new tire because the newer tire is less likely to flat, or because more riders have a more worn tire in the rear? Chicken or the egg? Is a worn tire in the front in the same danger since fronts rarely flat in the first place as is your experience? Like I said, there is an increase in chance of a flat as a tire wears, but how much isn't quantified and as long as you are within the safe limits of tire wear for that particular tire, the increased risk is overblown

MRT2

In my experience, flats are more common on the front tire. Last 3 years my wife and I have had 2 flats each, and all were on the front tire. Pinch flats are, perhaps more likely on the back tire, but I keep my tires inflated so that almost never happens to me.

I theory is, the front tire is more likely to hit a piece of glass, wire or debris before the rear tire.

FLvector

It's a combination of both and the weight causes the faster wear of the rear tire.

I believe both are true. Most riders (myself included) are guilty of allowing the rear tire to wear too far before replacing. I'd suspect most don't allow the front tire to do the same. If you replaced the rear tire every 1,000 miles, I doubt you'd see many rear flats, but who wants to replace that frequently? Too costly.

Yes, that's what I'm trying to avoid by rotating and keeping the front tire in good condition.

Do as you please, but I think the majority will agree with the suggested rule of keep the front tire in good condition by rotating the front to the rear, and putting a fresh tire up front. Just makes sense to me.

SpeshulEd 

I believe the question we should all be asking is how many miles do you have on the 23c tire? If it's only a few hundred, then I'd move the back tire to the front since it should be in relatively good shape. If it's a few thousand, then I'd put the 25c on the front and wait a few more miles for the back tire to go.

As others have said, you'll get a more comfortable ride with the wider tire in the back as that's where most of the weight is distributed and you can run a lower pressure.

MRT2

Depends. A wider tire on the front should, in theory, minimize vibrations and road buzz to the hands.

SpeshulEd 

True, but I already run a lower pressure on the front since less weight is up front, so wouldn't that already be minimizing vibrations and road buzz?

Bike Gremlin

But who cares about that? What's the problem with mismatched tyres?

CliffordK

Nothing, although it may be noticeable if you have a colored tire for one, and a black/grey tire for the other. Still, it is something that will wear out and be replaced a few thousand miles down the road, not the end of the world.

I did end up running mismatched tires on the rear this winter when I was experimenting with a Schwalbe Marathon on the rear.

redlude97

HrN? Mismatched tires just ruins the look of a otherwise matchy matchy $$$$ bike.

Pic

I just moved my 23 front to the rear and put a 25 on front. When the 23 rear wears then I rotate front to rear. I don't care if the tires don't match. I agree with Sheldon browns recommendation. Go with the odds that a worn tire will flat before a newer tire.

t3c9

Since you have decided to buy the 25C tire, why not try one end then after a while switch and see what you like better, then share your opinion here.

bmthom.gis

It looks dumb with the smaller one in the front on a mountain bike, though. Also serves no benefit.

Go wider up front, you will get better traction, and if you like it, get another one and rotate the front to back and put the new one on the front.

bmthom.gis

+1. My main commuter and both mountain bikes have mismatched tires. And whenever my next bike happens to wear out a tire, that bike will be mismatched as well. I have a single GP4000 sitting around just waiting to mounted on something

My main commuter has one black Schwalbe Citizen with reflective sidewalls in front and a grey Specialized (I think) in back...can't argue with free tires

redlude97

Are people actually getting better traction on 25's compared to 23's? I've never felt that way, 25's, especially on narrow rims feel like I have less traction. The bulge causes the sidewalls to flex and the tire to squirm when I dive into a corner compared to 23's.

wphamilton

I don't know about everyone else but I get better traction with a larger tire on loose surface and rough stuff. Which is why I said it depends on where I'm generally riding whether the larger tire would go in front or back.