I was wondering.

Is there any problem using 2 different tires on the same bike?

Say for example a fat 2.35 Big Apple in the rear for a more comfy ride, and a thin 1.3 racing tire in the front of a 26" bike?

would there be any gain at all vs. using 2 Big Apple front and rear?

I'm actually planning to keep my 2.25" Racing Ralph on the rear, and putting back the SportContact 1.6" on the front

i do quite a bit of off road riding, i figure the front wheel is just a driver, it doesn't really do much, all the weight is on the rear tire, and the push power comes from the rear wheels anyways.

on asphalt road i'm expecting to run normally, but going off road on the SportContact not sure if the front will dig into the dirt (grass) when it's too moist.

the Racing Ralph being so wide at 2.25 it has no problem at all on the moist dirt surfaces, but... can't say the same for the 1.6 SportContact street tire.

Anyways what do you guys think?

Currently using Racing Ralph in both front and rear.

Of course not.

Not a big deal. I use the same tires with dif widths (28 front and a 32 in back) unles I go on tour and have my bike "packed". Then I will use 32 front and back and take a folding 32 for a spare.

Could be a big deal for people with OCD.

My bike is 20"/26" F/R.

For off road it's usually the other way around, bigger tire up front and narrower tire for the rear, and the reason for this is that, with a smaller tire at the back you get much better and faster acceleration and makes hill climbing easier but the bigger tire up front gives you better cornering and control when making turns, and going over obstacles .Anyways 2.25 vs 1.6 is a pretty big difference. Personally I would keep the numbers a little closer together.

I run a pair of 2.2 WTB Velociraptors on my Ellsworth. The front tire has a strong braking tread and the rear has a strong push pattern. Fat as hell.

My MTB, cruiser and shopping bikes all have the same, front and rear.

My road/touring bikes have larger rear tires; 27" x 1.125F/1.25R & 700c x 25F/28R.

Somebody (I can't remember who) actually sells a set of racing tires where one is designed specifically for the front while the other is for the rear.

I don't know if it's mostly a gimmick or not but it makes sense. The work done by a front tire is much different than the one in the back.

I used to race BMX bikes as a kid in the 70s and 80s and every one ran compition II tires this way just for that reason. I still have my 1977 or 76 DG BMX bike

Having a Primo Comet 1.5" on the front and a 1.35" Kojak on the rear of my V-Rex bugs me to no end. I'll fix it in a few thousand miles when the Primo wears out...

I'm not a physicist, and I didn't stay at a Holiday Inn Express last night, but a lot of our MTB customers actually run a fatter front tire (larger footprint=better cornering grip), and a narrower rear (less weight). This runs counter to what people are accustomed to seeing on motorcycles, but then most people can't lay down the horsepower that a motorcycle can. I'm not sure if that same principle works on road bikes..... I'll have to do some asking around with the engineers. I'm guessing that on a road bike, there is some wind resistance penalty for having a fatter tire cutting the wind. The rear tire slipstreams behind the seat tube, so I wouldn't expect wind resistance to be as much a factor.

I recently put a 26x1.5 Comet Kevlar on the back and am about to put the same thing in a 20x1.35 on the front. It doesn't "Look Right" having a relective band on the sidewall of only one tire. Cheaper to make the change than to pay to talk with a counselor. (I wanted Kevlar puncture protection anyway.) Skinnier front tire is OK with this bike because of F/R weight distribution.