dannwilliams

I'm pondering riding with a 700-25/700-28 fr/rr combo on my Salsa Colossal. I purchased Conti GP4000's in the 28's. The clearance is real tight in front, I'm guessing they run on the larger end of the spectrum. I have a 25 left from my old bike and am wondering if I will experience any issues running different sizes tires. Any one have experience doing this?

OldsCOOL

You should be fine.

Barrettscv 

+1

Sheldon Brown considers a slightly larger in the front as a sensible combination. I often put a larger tire in the front if I expect soft gravel or earth on the route. I'll also put a larger tire on the back while loading the bike with touring or commuting gear.

dannwilliams

I would put the narrower tire in front. The Conti 28mm clearance is so close that when it picks up anything off the road, sand and such, hits the fork. The 25 has ample clearance. The tires that came on the bike had just a bit more room than the new tires.

GravelMN

The rear tire carries most of the load, so a slightly larger tire will allow you to run a lower pressure to soak up road vibration without risking pinch flats. The only potential downside I have heard to a smaller front tire is in cornering where having the smaller tire in the front than in the rear "might" increase the chance of a front end washout, instead of a rear washout or a full on broadslide, if you push it too hard in a fast, tight corner. Anyone who has had a front end washout knows they don't usually end well.

I have the opposite on my MTB where I have a 2.3" tire up front and a 2.1" in the back partially because of frame clearances but also to help keep the front end from digging into soft surfaces and to improve my ability to roll over obstacles.

JanMM

Mismatched tire sizes? Problem? - no problem!


Try it and see how it works out.

Wanderer

I run mismatched sizes all the time. Like you, I put the larger on the rear for comfort and capacity, and the more narrow for better handling on the front. Many, many years - work great.

Shimagnolo

I'm running mismatched right now on the summer bike, just to use up stock.
25mm GP4000 front, and 28mm Gatorskin on back.
I rather like the handling, but long term I'd rather use matched tires, so I can rotate front to back.

Bikealou

I put a pair of 28mm tires on my main ride, a road bike. Clearance in the front didn't work out. I replace the front with a 25mm tire. It is I working out well. I run the same pressure front and back. I got a relatively cushy ride and good handling. I have run 28s front and back in the past. Guess gatorskins run fatter for the same size. So far (about 500 miles) I am happy with the ride.

dannwilliams

Thanks. I guess I have nothing to worry about!

qcpmsame 

You should be fine, ride well and ride safely!

Bill

jodphoto

Like 28 slick in rear, 25 light tread in front. Back carries more weight and hits more bumps. Smooth sailing so far.

BlazingPedals

Bent riders do it all the time. No problem.

martianone

First set of tires on my road bike was 23 mm Conti 4Season, wore out the rear. Put on a 25 mm 4Season, liked the ride better. When the front 23 was worn, replaced it with a 25. Then, when 25 rear needed replacement - the shop only had a 28 4Season. The 28 actually did fit. 25 F and 28 R is working well, ride comfy, handling and speed good- tires wear at about equally.

Looigi

I'm currently on a 2.5" front and 2.3" rear on the mtb.

mrosenlof

+1 no problem. the two wheels are independent.

baron von trail 

I do the 28 in rear with a 25 up front now and then too because I often ride two 25mm tires on the weekend during summer, but need to beef up the rear for my commutes. In fall I run two 28mms.

John E

Contis run small -- I can put 700Cx28s, which are actually more like 25s or maybe 25.5s, on my Bianchi, and my son recently put 700Cx32s, which are more like 28s, on the PKN-10.

As for the mismatch question, I currently run a 700Cx28 in front and a 27 x 1-1/4" in back on the Peugeot, because my 27" front rim was wearing out. (I use the front brake far more than the rear.) I have a rear rack and just added a nice set of panniers, so this bike is often my "pickup truck," and the larger rear tire makes sense for this application.

Rogus

Not mine. 4000SII 28s measured 30.5.

dannwilliams

That is what I am experiencing. I had read many accounts of Conyi's running small, but these are larger than the Schwalbe Durano that came on the bike, and not much more than a hair width between the tire and fork. Rear spacing is larger, tho, so OK back there.

CrankyFranky

I've ridden 25F 28R for four decades, both touring and just recreational. Rough roads? No problem!

IsItMaxis

Ah you'll be fine i'm running WTB riddlers on the front of my Trek Fuel EX but maxxis ardents on the back same size same type been fine for the whole 9 months on that setup

jppe

A five year old thread!

MRT2

I would think if you had to do it, running a slightly wider tire on the front would give you better control.

Cougrrcj

I put Vittoria Rubino Pro Tech 700x28s on my '86 Miyata 710. Why? because as a near-Clyde, I like the shock absorbing benefit of the 28s. The rear has plenty of clearance, both width and height. The front -- again fine side-to-side, but < maybe > 1mm between the top of the tire and the fork crown. I'll put a 25 on it (good thing that I had the foresight to buy sets of the Rubinos in both 28 and 25! )... and keep the 28s for the rear...

Pic of the 28 on the front -



I had ridden through some fresh grass clippings that a homeowner directed to the road - and enough got picked up by the front tire that I came to a stop within a hundred feet like someone had applied the brakes! Yep, grass wedged between the tire and fork crown! I popped the quick release loose, cleaned the grass out, closed the release and rode home... 25mm tire coming soon to the front!!!