running different sized tires?
 

are their any advantages to running fatter tires in the front and skinny in the back, or the other way around?

I have 700x23s on my bike right now, but I recently got a 700x28.. Was curious if I should put it on now, and which side.

your gear inches will increase slightly with a larger tire on the rear. It'd be useful to put a bigger on the front if your bike has a forward sloping TT (pursuit frame) so you can take a little weight off your hands

aside from that, your gear inches will decrease if you put a smaller tire on the rear.

i like a 23 on the front and a 25 or 28 on the rear for a little softer ride and more durability.

i've always been told to put a bigger tire up front for better control in wonky weather, but i rode 18's all winter and was mostly fine. i really don't think anything other than spikes would've saved me from a dozen ice-related falls.

i vaguely remember a bmx guy telling me they run fatter tires up front and smaller tires in back for racing. hell if i know.

would 28 up front and a 23 on the back be too much of a size difference? Would I run into any problems?
Im new to this so i don't really know what I'm talking about.. But, wouldn't it seem wierd to run bigger tires up front?

I'm really hoping for better handling if I ever run into a lightly graveled road or somethmg.. Would the thicker tire up front help? Or should I put it in the back?

If it helps, I have a fuji track frame.

28 in back for the sweet tarck skidz, 23 in front

my boss rides a 69er and says the trails are so smooth they bore him now.

fyi.

what does that have to do with tire size?

some frames won't clear a 28 between the chainstays or under the fork crown, fyi. trek t1 has about 2mm on each side, i had to grind the rear bridge on my track pro, and i've seen several keirin bikes that only fit a 23.

Sheldon Brown's commentary LINK
Scroll down to Mixing/Matching Tires.

Mixing tires is pretty common for off road bikes without suspension. Running a big tire up front gives a little bit more comfort/traction/pinch resistance for bumpy trails. I ran a 2.3" front and 1.8" back for a while.

On the street, it could help prevent pinch flats from curbs and potholes. But I get most of my pinch flats on the back, so thats where I'd put it.

I've got the impression that for general riding on the street, using different tire sizes won't really make a noticeable difference, or at least not a noticeable improvement. But experiment away and let us know if you come across anything.

I sometimes run a bigger tire in back 60% of my weight is, well, a lot. In order to have the right pressure, I exceed the max psi of most smaller tires.

28c, front and rear.....Im going 32's on my next bike

I'm riding on 35mms right now and it's really lovely. The ride is more comfy, you can ride over rough road a little easier, and you get better tire to road contact in the rain
http://farm3.static.flickr.com/2128/...34c83084_b.jpg

yeah i run my BMX set up like this for traction. i could see this possibly staying true for a road rig though i havn't actually tried it out.

i runs 23 in the back and 20 in front i likes it

i rode 23 front and 28 rear for a long time and the difference between 23/23 is negligible.

I set my bike up today to do some singlespeed cyclocross, and I used a 38 in the front and a 32 in the back. I think that setup is about as comfortable as a cross bike can be. The traction was impressive with this setup also, but that might just be because the last time I rode off-road was with 23mm tires on my fixed gear with one brake. HARSH.

how big a difference did you expect? lol!

+1

You waste more energy thinking about this problem than just either

a) doing it
or
b) running same size tires

My fork only has clearance for a 20 (or some small 23s) in the front. I usually ride a 23 in the back.