MinnMan

As others have said, there's no "must" to this, but I find 25s at slightly lower pressure (say 90 psi rear wheel) to smooth out some of the roadbuzz of chipseal compared to 23s, which I run at about 100 psi on the rear.

However, at 260 lbs you may be near the limit of 23 mm tires without inducing perhaps more than ideal wheel drop (or overinflating). There's a relationship between your weight and the ideal pressure for tire performance and of course you don't want to exceed the recommended maximum pressure. See

https://www.bikequarterly.com/images/TireDrop.pdf

fstshrk

If you can fit 28s, I would go with those personally.

E.S.

Wear the 23s out and change em later if you want. I weigh 225 atm and I rode all last summer-fall on 23s.

TromboneAl

I recently changed from 25s to 23s, and didn't notice any difference in feel.

But there is a big difference that no one has mentioned:

With 23s, you can take the wheel off without opening the brakes (and without forgetting to close them again).

MinnMan

Let me state that another way - at 260 lbs, you are flattening out the bottom of a 23 mm tire as you ride and creating additional rolling resistance - just like driving a car with underinflated tires decreases fuel efficiency. You can't cure that with 23 mm tires b/c at your weight the pressure required to keep the tires from deforming too much exceeds the rating of the tire.

As long as your wheel is strong enough, there's no safety issue for you riding 23 mm, but when you do move to 25 mm at some later point (assuming you are the same weight at that time), you'll get an increase in performance. In fact, looking at the tire drop chart a second time, at 260 lbs you'll be marginal for 25 mm tires and, at least in back, might be better of with 28.

Swo0p

Alright. Think im putting the 28 (and stronger anti-flat) on the front wheel and 23 on the back

cplager

Hi,

O.k. What am I missing?

First, why not put 28s on both front and rear? Second, given that most of your weight is on your rear wheel, having a skinny tire back there makes less sense. So if you were going to run different width tires, I'd put the thinner tire where you have less weight.

Cheers,
Charles

Dan333SP

Not always true. The 3 road bikes I've owned required opening the brakes to remove the wheel even with 23mm, IF the tire is fully inflated. 40 PSI and it'll squeeze out.

Swo0p

I thought about that to but I feel like the front wheel is always more likely to hit road debris than the back one. Plus its the steering wheel.. thought the conti gatorskins would be a more solid choice there. Basically im just throwing on a mix of speed and more comfy experience. And I want one yellow tire on my black/yellow bike. Don't judge

Will G

210lbs, 23's were no problem but switched to 25's to ease the vibration caused by chip seal.

MinnMan

Well, again, whatever you like, but my experience is that flats are much more likely on the rear tire, where there is more weight. Maybe my experience isn't statistically characteristics of everybody else's experience, but I'd guess that front/back flats are something like 1/5 or so.

squatchy

I weigh 240-250 and made a switch from 23 to 25 and I like the difference. I must also say I went with a wider rim at the exact same time so my experience is just a tad different than "tires only" comparisons.

cplager

But, but, but....

O.k.

StanSeven

You probably need to adjust your brakes then. Ideally the pads should be close to the rims; so close that one needs to open the calibers to take the wheel off. That's not true all the time but for most wheels it is

laserfj

Moving to 25s was one of the the best decisions I ever made relating to cycling.

YMMV

Swo0p

Ok! useful 'statistics' i can use.. in that case..... i will give the 23 mm in the front a shot first and see how it goes the yellow 23 mm tires didnt even arrive yet so maybe it looks dumb enough that im going to pretend i never even considered it..

nhluhr

Depending on the wheels you have (wide rims?) and your model of Scott bicycle, you might find 25s to be a too-close fit that results in rubbing on the frame or fork. The CR1 bikes in particular have surprisingly little clearance in the fork for wider tires.

Carbonfiberboy 

Another absolutely no-point comment: We are a 305 lb. tandem team, meaning our all-up is probably 350 with bottles, extra clothes, etc. This Sunday we had a 4-flat ride due to wet, glass-covered roads. Small glass bits, slow leaks. We were running 25c Ultremo DD, a 260g tire. We got tired early because for a good part of the day we were unknowingly running on underinflated tires, probably down to 60 lbs. before we noticed them. When we had the last flat, we were only 10 miles from the barn so I put on our emergency spare, a 23c Tricomp (225g tire), on the rear and pumped it to 130. The bike just took off. We went from tired to TTing the last few miles and accidentally rode our racer girl companion off our wheel. It's energizing to ride a bike that will go. So lets hear it for pumped up light tires.

It wasn't just us - another tandem team on a different route that day also had a 4-flat ride.

fiataccompli

Two observations, sorta already mentioned, but anyway....some 25mm tires are wider than other 25mm tires. Continentals, for instance, run narrow in my experience. I have 28mm continentals on a couple bikes and it's a nice size for all but racing, I'd say..but probably won't fit a lot of modern "race" frames/forks. When I buy tires now (for road riding), I usually get 25mm, but I'm not tossing my 23mm tires...I have a lot of bikes with those and I'm going to use them until they're no longer reliable before I replace them with 25s. Guess that's to say there's a difference & I do act on it when buying tires, but it's not enough of a difference to warrant buying tires just for the change.

an alternative approach is go buy the 25s now..buy 3 so you can square out the rear & replace it to keep up with the front. Give your 23s to a college kid or someone getting into cycling but without the cash to lay down for nice new tires!

Dan333SP

Looks like I'll be able to offer more insight to this soon- I've always ridden 23mm Gatorskins, but I ordered a pair of 25mm GP4000S tires (basically, the official tire of BF) in advance of 4 races over the next 2 weeks. I'm 175 lbs, so I'm thinking that I can drop the pressure from the 105 I usually run in the Gatorskins to ~90.

mynameistaken

25s are a good compromise.

koolerb

That tire drop chart is great. Thanks for posting.

fstshrk

Specialized makes a 23/25 Roubaix. That's what I would use.

hhnngg1

I found that the comfort of a 25 vs 23 exceeded the carbon cs alu damping effect

spectastic

going to 25s will save you a lot of flats.