smurray

I have a Panasonic DX-3000 from the late 80's I bought off of Craigslist. It came with a 28c tire in the rear, and a 25c tire in the front. Both tires needed replaced, so I tried to put 28c tires on both the front and back. Unfortunately it's too tall in the front and rubs the fork. Would I be better off going with 25c all around, or leaving the 28c in the rear and putting a 25c in the front? What would be the advantages/disadvantages of both options?

pdedes

Bigger the tire, the lower the air pressure needs to be. Comfort is one reason, and to a certain extent you can lower rolling resistance with wider tires too.

smurray

I understand what the advantages of larger tires are, I'm more interested in specifically the advantages or disadvantages of running a larger tire in the rear and front. I will mainly be using the bike for commuting and for riding around town, if that makes any difference.

shelbyfv

I had this problem with a Bridgestone RB2. I found that the fork steerer extended below the crown and could be filed for additional clearance. I also found that reducing the tire pressure made it less likely to rub. As for your original question, I would say it depends on your weight. If you are heavy, keep the 28 on the rear.

hairnet

The larger tire on the front wheel will feel more comfortable than having it on the rear wheel. Since it doesn't fit you can get two of the same narrower tires or do as the guy above said.

jayp410

The only major difference should be pressure. Since weight distribution is about 60% on the rear wheel, if you were going with 25/25 the ideal pressure in the rear would need to be higher than the front. (I run 100/110 PSI, at 195 lb, and 25/25 front/rear, which is probably higher than necessary). With a 25/28 setup you could run a lower pressure in the rear - the ideal front/rear pressure would probably be about equal.

Commodus

I like to have a bigger tire in the back, I've run like that before. As has been noted already, you can run equal pressure and makes it a bit more comfy. Not a huge difference, certainly, but since you already have it and there's no downside...I say go with it.

fordmanvt

I've done exactly this with a 23/25 split.

Lexi01

Ha - wierd. I was thinking about doing this just today cos I have a spare set of 28s at home.

Is it really that much more comfortable?

AngrySaki

I have a bigger tire in the back because I can't think of a reason to spend the money to get matching tires (23c/28c). I can't think of any issues I've had.

FrenchFit 

The larger tire in the back handles weight better, so if you are heavy or carry loads the rear rides smoother yet the front steers lighter going 28/25.

Personally, I prefer using a different type tire in the back for commuting or loaded riding, like a 25 'hardcase' in the back, a fast 25 it the front. A few of my bikes are set-up with 25c Gatorskin in the back, 25c GP4000 in the front...besides giving a nice ride it cuts down on rear flats for me. On my 27" wheel commuter I use 1&1/4" in the back, 1" or 1&1/8" in the front.

ColinL

It's not a linear relationship and the tire brand & model matters a whole lot. At least as much as the tire size, and probably more.

17 to 20 to 23 are huge steps in comfort and ride quality. 23 to 25 is a more moderate increase in comfort and ride quality. 25 to 28, less noticeable.. And so on to where you probably can't tell the difference between a 32 and a 35 by size alone. (Jumping all the way to a 29er is different, because it's a lot more air volume and larger diameter.)

I have a 23 front 25 rear right now because my original 23 suffered an unrepairable cut and I bought a single 25 to replace it. After this, though, I'll be riding 25s front and rear and that's what I just put on my wife's bike.