6StringJazzer

I am replacing a tire that is 700x23c. I can't tell from the wheel what the size spec is, so I am going from the previous tire. The store only has a 700x25c in stock, and the guy tells me such a small change in width won't matter.

Is he right, or just trying to sell me a tire?

Badger6

He's right. Note, you'll inflate the 25s to a sightly lower pressure than the 23s.

phtomita

And you will get much more comf when riding it

6StringJazzer

Thanks. The specs on the box do say that the pressure for 700x23c is 110 psi. Oddly most of the other sizes, smaller and larger, are 95.

I'm not really after comfort. I'm not a competitive rider but I've been riding on 115 psi just fine for years.

PeteHski

Is that 110 psi recommendation for your weight or just a generic figure for all?

biker128pedal

How much clearance do you have now and what is the inside with of your wheels. The 25mm tires may rubb.

I had a Madone 5.0 and upgraded to carbon wheel with inside width of 19.5mm. The old 14mm inside width rims worked with both 23 and 25mm tires. Even GP4000. Not so with the 19.5mm wheel. Opened the tires up. The 25mm tire rubbed on the chainstay in back and the fork crown up front. Newer bikes tend to have more clearance.

veganbikes

Generally I recommend going as wide as possible so if your frame has clearance go for a wider tire, You will thank me and the person who sold you the tires. Wider is better up to a point. Certain bikes are for racing or are quite old school and have limited tire clearance (Clarence) but generally 23-25 isn't so bad and will likely fit unless you have a bike designed purely for racing that is older. A lot of Keirin bikes have almost no clearance nor do they need it for track racing where everything must be the same.

cxwrench

Pressure is based on rider+bike weight and tire size. 115psi is ridiculous. Period. If you 'need' that pressure what you really need is bigger tires.

CliffordK

It will really depend on the bike. My Funny Bike really doesn't like anything wider than 23mm. I suppose I can fit 25mm in, but it will be awfully tight.

I've heard of quite a few bikes from around 2000 to 2010 that did better with 23mm (TT, Tri, etc).

Badger6

That spec is somewhere between a guess and wish.

Use this calculator to get the right pressure for any width tire, as measured.

And, wider is more comfortable, because wider means more volume, and can be run at lower pressures which means the carcass can flex a bit more. 25s won't be plush, but they'll be slightly more compliant than 23s.

6StringJazzer

I don't "need" that pressure. It's the recommended pressure for my tires, which show a max inflation of 160. And what would bigger tires do for me?

6StringJazzer

Yes, I have found exactly what I want on the Internet if I want to wait a week for delivery. That's an option but I ride about three times a week and would prefer not to wait.

rumrunn6

fwiw - past several years, I've been running my fronts approx. 10 psi lower (less diff. w/ the MTB). for example at my last pumping of the road bike I went to 100 rear 90 front. but since they burp when I take the chuck off they are closer to 90/80. these are 25mm tires & I'm approx 225lbs +bike, etc

6StringJazzer

Thanks for that. For my setup the calculator says 105 psi (slightly different front and rear).

If the carcass is flexing more, doesn't that increase rolling resistance? Comfort is not really an issue.

dabac

Depends very much on the design of the tire. A tire with supple sidewalls create less rolling resistance than one with stiff sidewalls.
And let’s not forget the influence off the surface you ride on.
If you have infinitely hard tires, then anything you hit, you have to roll up-and-over. And that upwards motion steals some forward movement. A softer tire allows minor irregularities to sink into the tire instead, preserving forward motion better

Badger6

As the poster above said: it depends. On a quality tire, with at least 120tpi, it may actually reduce the rolling resistance! On a cheap tire with a low thread count, 60tpi or "unpublished," the tire will feel stiff and though you may not feel it, the rolling resistance could be higher....of course, this discussion of higher or lower is relative to what you currently have, which I am guessing is a mid-range 23.

As for comfort, I didn't;t know what I was missing until I tried it. I can remember the rides and the conversation clear as day that I had with a guy on Veterans Day, 2014....the topic of tire width came up, he told me he was on 25s, recommended it, I tried it the following week....today I roll on 27s (summer) or 30s (winter) on my road bikes, and 32s on my "rain bike", and I can assure you the comfort matters. I live in a land of busted roads, and some are still made with cobblestones. Unless you only ride on pristine, new tarmac....comfort matters and will make you faster.

cxwrench

160 is the max pressure the manufacturer found that is 'safe'...more and it may blow off or damage the rim. It has NOTHING to do w/ the pressure you'd actually ride the tire at. Bigger tire=more traction, better rim protection, better comfort and very slightly less rolling resistance.

No, you're not losing any pressure, that air is only coming from the hose, not your tire.
No, it doesn't...it actually improves it. As posted before a very hard tire will bounce off every little imperfection in the pavement. By definition that is rolling (or bouncing) resistance. Tires are the only suspension on a road bike, you have to let them do that job to a certain degree. There are no negatives to reducing pressure to a reasonable level. Why would you not want any of those things? How do you know comfort is not an issue if you've never tried it? You don't know til you know. And...why are you so worried about speed as a recreational rider? None of these things make sense. And of course, it's free to try. This has been such a hot topic for the last decade I can't imagine how stubborn you'd have to be to totally ignore it.

Iride01 

My tires don't have any coarse aggregate to bounce off. They roll better at 125 PSI than they do with 90 PSI. My legs and data collected have told me so.

cxwrench

If that is the most important thing to you...I don't know what to say. I can promise you that you have less traction and lower comfort at 125 than anything lower. And I'm pretty sure not every road you ride on is velodrome smooth...that doesn't happen in our country. No way. It doesn't have to be 'coarse aggregate'.

70sSanO

^ This is what you need to do.

You can look up your inflated widths online, bicyclerollingresistance.com, to see if it will fit.

I personally could care less what pressure you like, the only thing that is important is to make sure it will fit in your frame.

John

CliffordK

The trick is to plan ahead on consumables, so you just have to grab the part out of the closet.

cxwrench

An entire week?!? Oh no...that's a tragedy.

datlas 

It’s late but I think 25 is a good idea. And yes you are probably over-inflating your tires by 10-20PSI. It’s ok, most people pump their tires to “max” pressure on sidewall which is understandable.

PeteHski

Back in the day when I was still running 23c tyres and you had to download websites to read them, I just ran them at 90 psi and that was a plenty harsh enough ride! Now I run 30c and 32c tubeless at around 60-70 psi. I weigh 175 lbs.

If you have clearance for 25c I would take those and experiment with lower pressure. Unless you weigh a lot more than me, 90 psi should be more than enough.

6StringJazzer

OK, thanks to everyone for your help. I decided to go with Continental Grand Prix 5000, and I found them on Amazon for Prime delivery for free tomorrow. (My regional bike shop stocks these for $80; I just ordered two for $100.) I'm sticking with 700x23. Based on other comments here I will probably roll the pressure down a bit, but as I said comfort has not been an issue.

I am not plugged into cycling discussions so I'm unaware of this as a hot topic, or what people are saying. All I know is my own experience. The hot topic I follow is whether round-wound or flat-wound strings are better, and what scale to play on a half-diminished 7th chord.

Yes, that's why I keep a couple of tubes on hand but now I will keep an extra tire, too.

Re: Weight, bike + me = 190 lbs.

Also: I found that I could not post more than 5 times in a 24-hour period so I had to wait to post this. Also I cannot post links or images yet.