What are the pros and cons of putting different tires on the front and back wheels, especially for commuting over rough pavement and potholes? Is this even done or do people always get matching tires? I'm thinking of putting a road tire on the back wheel when the current tire wears out, but the front tire is still going to be in really good shape. These tires are wide ATB-type "city"...is putting a rear tire on that's a different size unsafe or will it make the bike handle poorly?

mmm i remember reading the sheldon brown site about tyre choice. I hope this is right and Im not referencing wrongly to Sheldon Brown.
A slightly thicker or skinny tire is ok. Dunno about what you want to do.
Maybe just chuck both new tyres on, and notice the speed increase. I would suspect a weird tyre selection would make the bike handle poorly

guess the back tire would wash out more often if the rear was more of a slick tire than a knobby...

if you must use the slick tire, put it in the rear. it may slide out sometimes, but having the knobby with good tread up front will keep you upright because thats what you steer with. why do you want a knobby tire? for the city it has a very high rolling resistance.

i have a question about mixing tires: what if you were to mix slicks/semi-slicks(on a MTB) that were different sizes? would this be okay? for instance, you have 26/1.5(FW) and 26/1.6(RW) or 26/1.25(FW) and 26/1.5(RW)?

on my mtb i always run a WAAAY bigger front tire for increased cornering and bump absroption. no worries at all.

i'd always stick the bigger one on the front. also, the rear tire seems to contribute more to rolling resistance than front tires so having a higher psi smoother tire back there will get you the most performance advantage.

plus as the other poster said, ideally you want your rear tire to wash out before the front. not that you really want either washing out but i hope you get the idea

Absolutely not. Other way around. Knobbies and even inverted tread patterns provide zero benefit to traction on paved surfaces. A slick tread provides the maximum possible traction and minimum possible rolling resistance. However, the rear tire is less likely to "wash out" in any case. The critical tire for cornering traction is the front tire. If you are cornering aggressively, it is much worse to have that knobby in front, since they often lose traction unpredictably and very abrubtly, and always at lower speeds and angles than their slick counterparts.

There are plenty of good reasons to put differently sized tires on the front and back. And so far as I know, there is no rule against mixing different tire makes and models on your bike, either .

I'm on 27 inchers. I ride a 1 1/8 on the front and a 1 1/4 on the back. The rear has to support more weight and takes more abuse. A larger tire can absorb more impact without detriment.
This setup also gives more comfort to my tukus .

On a ridgid a fat front tire will help reduce some of the impacts to your hands and wrists and improve traction to your steering wheel. The rear wheel is more heavily weighted so a narrower high pressure tire on the rear will have more effect on the rolling resistance.
For the same size wheel the difference in tire size is usually too small to be noticable in changing the geometry of the bike, so I wouldn't be concerned.
For off-road a fat knobbie front tire with a slicker rear tire can be effective in dry conditions but for road commuting stick to slicks. Knobbies will only slow you down for no good.
A nice commuting combination might be a Big Apple front (2.0" or 2.35") with a 1.5" slick for the rear (Marathon Slick?). Also consider you are more likely to get a flat on a rear tire so I would spend more for flat protection for the rear tire than the front which maybe OK with a cheap tire.
I usually run the same tire or nearly the same as I try to fit as large as possible tire on my road bikes. For MTBs you have much more flexibility in tire width.
Craig

I run a 26x2.0 80 psi knobby rear, and a 60 psi 26x1.9 front.

the 80 psi helps in the rear more than the front by deforming less

As others say, slick goes on front for best traction. I'm running with 700x30 slick on front and 700x32 regular on rear. "Problem" is feel more bumps because both not slick. But the problem is not yet great enough for me to buy a new tire. New Attack force tires have different sizes for front and rear.

ahhh dank u, dank u! much thanks, great posts and as always very helpful.

Its conventional wisdom among BMXers to run a fat tire up front and a skinnier tire in the rear. BMX races consist of short straights with jumps and a number of extremely tight banked corners, all on dirt. I've always thought that the big tire up front gives better handling and traction through the turns. I've never actually raced BMX..I was more into freestyle. At any rate, I suppose that would make sense for conditions other than dirt as well.

I run a 26x1.5" slick in the front for comfort and maximum rubber patch on the road. The rear is a 26"x1.8" with deep tread and a profile similar to a slick (negative tread?). It's comfortable and still has bite when I hit loose dirt or very wet grass. I cut across a local park to avoid a bad intersection.

This combo works for me but it really depends on the path you use. If I was always on nice clean asphalt I might be happier with a pair of 700X32 on a road bike.

I commute on an inexpensive mountain bike. I replaced the WTB Velociraptor front tire with a much narrower and pavement treaded tire from th local LBS, WalMart. I left the rear tire alone. It's a WTB Velociraptor. Its wider and has big knobs. I hope they protect me from all the glass I have to roll over getting to work. Even the MUP I use has lots of broken glass on it.

I think people have been using mismatched tires since the invention of the pneumatic tire.

One day, I will get a big street tire for the rear and put a Tuffy liner in it. I commute 22 miles a day, five days a week.

thanks for the advice, when the back tire is worn out there are more options now. the current tires are specialized infiniti 700x38 100psi. i've picked glass out of the tread and no flats yet, pretty good for a stock tire but road slicks are the next thing to try.

It's your bike/your choice!

--- Check out this thread on the Bicycle Mechanics forum dated 01-04-05 entitled "Tires: Mix or Match?"
www.bikeforums.net/showthread.php?t=81847

My preference is to use the same tire front and rear, but I won't throw away a perfectly good tire. When I discarded a damaged 26x1.9 and replaced it with a 26x1.5, I couldn't see throwing out the still good 26x1.9. I kept the larger tire on the front. Three reasons. Loosing your grip on the road is more catastrophic for the front wheel compared to the rear. Second, more weight is on the rear tire. Putting the more efficient tire back there gives more benefit than the less loaded front. Third, emergency braking is done with the front wheel. I think braking benefits from the larger surface area.

No, this is right for dirt but i would do the opposite for pavement. As others have said, slicks have better traction on smooth surfaces, so should be on the front for street riding. I guess you would go the other way around for riding on loose surfaces.

One other point. If you do mix tires, make sure your spare tube will fit both. For example, a 1.5 tube will fit 1.25 and 1.75, but maybe not 2.25. If your two tires are real far apart in side, you might need two spare tubes.

With regard to BMXers, I wasn't talking about tread...just tire width. It makes more sense to have a wider tire up front. Obviously a slick would work better on smooth pavement...front and rear.

Thank gawd for the search option, I was just thinking about this today. Currently I'm running 700x32's front & rear and have been thinking about trying 35 up front and keep the 32 on the rear. On my 7.5 mile commute to work it's on pretty rough pavement that hasn't been redone in some time. The ride home however is much nicer as that side of the highway was re-paved last year. One concern is I don't want to carry 2 different size spare tubes so I've considered running the 32 up front & 28 in the rear. Are there tubes that fit 32-35? I really want the 32/35 as it seems that would provide more benefit than 28/32, yes or no? Will 1 tire size up or down really make a difference? Perhaps a 28 rear & 35 front might be better & just carry the extra tube?

Do yourself a favour, put the wider tire in the rear - provided that you have enough space for it. You'll want the wider tire in the rear, where the bulk of your weight is concentrated. It will provide more cushioning and better traction.

Personally I run 700c x 32 in the rear, 700c x 28 up front, though the tire I had on the front before this was 700c x 25.

I did this all winter. 26x1.5 street tire on rear. 26x1.9 knobby on front at low PSI. You don't want to lose traction on the front tire.

Alot of people who have studded tires only use them on the front.

I think most of your weight is on the back wheel. So, it makes sense to use a skinnier high pressure tire without knobbies back there. More efficient. Not much increased danger due to loss of traction. Note, I did have to walk up the big hill once this past winter. Studded tires in back would have helped on that day.

Edit: Looks kind of dorky, though. Guys at work were making fun of my bike with the non-matching tires.

Since the back supports more weight than the front, you might want to run a slightly larger rear tire and smaller front tire so you'll be fast but still have support with higher pressure tires. Plus they both wear out at the same time so you don't end up with a worn rear tire and a 60% used front tire.