Amen

Pointless?

Why do people do it?

CrimsonKarter21

Because they put so much power to the rear wheel that they need the extra traction like a Top Fuel.

garysol1 

I have never seen that done...or at least I have never noticed.

bonechilling

Wider tires distribute the load a little better. Since you have more weight in the back, you put a larger tire back there for some extra cushioning. At least that's the reasoning, I believe.

CrimsonKarter21

Yeah, I'm thinking that it's a combo between mine and Bonechilling's ideas. Everyone wants to be a sprinter.

jaxgtr

I've seen it and never really thought anything about it. In the big scheme of things, it a pretty minor difference since true tire size is a wag at best.

Sixty Fiver

I run a 28/25 front rear on my fixed road bike... it doesn't really affect my top speed and makes for a better ride.

NRRider

I do it on one of my bikes simply because the fork doesn't tolerate a 25 tire (otherwise I'd have the 25 on the front too). Not sure the 25 in back provides a noticeable difference in ride quality, but I've been riding 25's for a while and they are working well for me.

urbanknight

That's the reason my father did it. Worked great as well. As a heavier person, it arguably had LESS rolling resistance than if he had gone with 23s all around. Run a search if you don't know what I'm talking about.

timmyquest

You've been talking to some real ego's huh?

djbowen1

conti attack & force s tires come like that this year

CrimsonKarter21

Thinly veiled sarcasm, bub

sunburst

Well, I've got a 25 up front, with 28 in the rear! Both conti gatorskins. I was trying to turn my 20yo short-wheelbase Trek into a semi-plush bike and thought I read in Bicycling to buy this tire in 25. After buying one, I re-read and they said use 28 for plush, or all-day riding, or centuries, whatever. So I went back and bought a 28. I needed another tire anyway (or told myself I did!). It looks frickin' huge! But it works, and I'm not racing anyone anyway, so if it slowed me down a bit, who cares.

Btw, it did not magically make the Trek a plush bike. It cannot begin to compare to my new Giant OCR C1. Giant put 25s (Michelin Pro2) on it, and so far, I like those tires quite a bit. Don't know how much they contribute to the feel of the bike, but on my first ride, it really felt like the tires themselves were especially compliant.

bostongarden

Until about one month ago -- when I needed new tires -- I ran a 28 (Conti) on the back and a 25 (Michelin) on the front...I raced with this setup through the mid-1990s and it worked great...I decided to try a 25 on the back and a 23 on the front...feels good too...to my eyes there is a noticeable difference between the 23 and the 25 for Michelin...the 25 Michelin looks like the old 28 Conti I had on before....if indeed I race again -- just back into it since October 2007 -- I'll go with this setup with confidence....

AEO

you can get a slightly taller gear with a bigger tyre on the back.... not even a 0.3mph increase though.

timmyquest

That's what makes it sarcastic, bub

bonechilling

I should also add that I run a 23c on the rear of my track bike, and a 21c in front, since the clearance is too tight to fit anything larger.

Silvercivic27

Was wondering if anyone has tried this since this post. I recently bought a 25 to replace my rear tire, so I'm running a GP4000s in 23/25, similar to the attack/force 22/24 combo. Anyone else tried this? Opinions?

canam73

It's just plain cool to have a secret little trick like that.

ahsposo 

<cough>

How about 21/38?

Puhleeze! It's crap like this that gives the 41 it's rep for stupid.

That and Addiction.

E.S.

Not pointless.

I have previously run (road slicks) 28back/23front and 28back/25front on my old cross bike before I went 23/23. It's not going to/never did hurt performance. Theoretically it might reduce rolling resistance, make a smoother ride, and be less flat prone for the rear tire where more of your weight is. My current road bike came with Vittoria Zaffiro Pro 25's but I am running 23 Conti Hardshells right now. Earlier this month for a dirt road ride I used 25back/28front because that was the maximum clearance.

escarpment

I do it. Maybe it makes a difference, form of habit for myself.

1c3y

I run 23/25 with gatorskins because the roads are pretty rough here...

caloso

I've done it. Works fine. More cushioning on the tire that supports the most weight.

Bike Gremlin

23 tyre needs to be above 7 bars for my weight. It is very prone to collecting broken glass (hard, doesn't give in, so glass cuts through it). 28 mm in the back would be pumped at 5.5 - 6 bars, so much softer and less prone to cuts it should be. My next tyres will be 28 mm wide conti 4 seasons. I now ride 23 mm wide Specialized All Cond. Elites.