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I know the different characteristics of individual tires could influence some answers to my questions, but those aside:

What should I expect to notice about differences in ride, handling, etc. etc.?

Will I need to recalibrate my computer?

Anything else I should know before making the switch?

I have used 700x25 tires forever because the roads were so bad, but I've moved and now have copious bike paths and decent roads. I'm thinking of moving down to 700x23s for a change. I don't race, but I do like to do my share of hammering and distance rides. I weigh about 165 if that makes any difference.

thanks for your help.
 

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Minor change

texass4 said:
What should I expect to notice about differences in ride, handling, etc. etc.?

Will I need to recalibrate my computer?

Anything else I should know before making the switch?
At your weight, you should have no problems with the 23s. Assuming you inflate to the same pressure, your computer reading might not change much, but you can check that easily by getting the distances with each tire size over a known route. This will be tire dependent, as some 23s are as big as some 25s. Handling and ride won't change that much either - biggest change will be a different brand/model of tire so unless you get the same tire in the next size smaller, you won't really be able to separate size effects from all the other issues.
 

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Kerry Irons said:
This will be tire dependent, as some 23s are as big as some 25s.
Are you able to provide any specific examples, please?

I've ridden 25s for years (mostly Conti Ultra 2000s) but they're getting harder to find at good prices ... lately it seems like every tire listing I've looked at on Nashbar or Performance is only available in either 700x23 or 700x28.

How do the Michelin Carbons run, size-wise? Based on the generally favorable comments I've read here, I've been considering trying those.
 

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No specifics

Allez Rouge said:
Are you able to provide any specific examples, please?

I've ridden 25s for years (mostly Conti Ultra 2000s) but they're getting harder to find at good prices ... lately it seems like every tire listing I've looked at on Nashbar or Performance is only available in either 700x23 or 700x28.

How do the Michelin Carbons run, size-wise? Based on the generally favorable comments I've read here, I've been considering trying those.
I've not made it a practice to keep track of whose tires are what size, I just know that this is often referred to as an issue. You would think that it would be easy to mount a prototype tire, measure it, and then put that size on the sidewall of the production version. However, that doesn't seem to be the case.
 

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23 vs. 25 computer mileage differences

I'm a newbie, but I have ridden 23's and 25's with two different computers...

For me, the 25's roll smoother, but I'm old and slow, so I'll take anything I can get.

On the mileage, it does make a difference although it's a small small difference. Over a 23.39 mile route (ridden a billion times with two different bikes), the computer set to 700 x 23 with 25's read 22.97 miles. Not a big deal, but the mph reading were way different - I thought my new wheels were slower at first, then I adjusted my computer to 700 x 25 and all was good.

Computers were sigma and then a shimano flite deck.
 

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i'm in a similar dilemma,

i'm trying to find out what the largest size tire is that i can fit on a motobecane messenger. i have some 700x25's on it right now...but, i weigh around 200lbs and i would like something with more rubber between the ground and me, plus some tread for rougher conditions.

anyone have any suggestions?
 

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This leads me to a question I have always wondered. A 23 mm width would be more aero and lighter, thus faster except for the fact that a 25 mm tire of the same model usually will have lower rolling resistance. So.... which tire is ultimately faster the 23 mm with the lower aero drag and lighter weight or the 25 mm with the lower rolling resistance?
 

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jrz1 said:
This leads me to a question I have always wondered. A 23 mm width would be more aero and lighter, thus faster except for the fact that a 25 mm tire of the same model usually will have lower rolling resistance. So.... which tire is ultimately faster the 23 mm with the lower aero drag and lighter weight or the 25 mm with the lower rolling resistance?
Why are you saying that a 25mm will have less rolling resistance? There's more rubber touching the road. I'd agree that it has less rolling resistance if it was tubeless (vs a tubed 23mm tire), but that's about the only scenario that I can think of that being the case.
 

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dookie said:
you will gain nothing on the 23s. well, ok, a trivial weight savings. the 25s will be faster, more comfortable, and longer-lived.
I guess that explains why all the pro's race on 25s. Seriously dude, WTF? If they only knew what you knew I suppose.

OP, You'll be fine with 23s at 165. It may mean you need to adjust your computer a little to be dead on but realistically no more likely than going with a different brand of 25s.

Keep in mind that people love to argue this topic of 23's v 25's and usually what happens is no one mentions their weight so it's probably some load preaching to a fly weight that 25's are a better choice or visa versa.

I weight just 5 less than you and for good roads, I think 23's would work out well for you. Don't expect anything drastic but I feel they roll a little better on nice roads without giving up much, if any, comfort.
 

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A 23mm wide tire has a longer (front to back) tire contact patch than a 25. But the 25mm wide tire has a wider (side to side) and shorter (front to back) contact patch than a 23. Also under hard cornering, the 25mm wide tire provides more grip than a 23mm wide tire.

http://www.schwalbetires.com/tech_info/rolling_resistance


The difference is minimal, and most people can't tell the difference. What you need to worry about is flat protection and ride quality. With a 23 tire, I had to have the tire pressure set to the max - 120psi to help prevent flats, but had a downside of a much rougher ride. With a 25 tire, I can run lower pressures 105 R/ 100 F, still get the flat protection and have a much more comfortable ride.

BTW I'm 6'2" 180 on a good day in the middle of summer. Most of the time I hover around 190.
 

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frdfandc said:
A 23mm wide tire has a longer (front to back) tire contact patch than a 25. But the 25mm wide tire has a wider (side to side) and shorter (front to back) contact patch than a 23. Also under hard cornering, the 25mm wide tire provides more grip than a 23mm wide tire.

http://www.schwalbetires.com/tech_info/rolling_resistance
I read the article, and I didn't see where it said that anywhere. I saw where it talked about the tire flattening out (width), but I don't see how a tire can stretch the rubber to change the contact patch of the tire.
I wouldn't see how the contact patch could be any different on the 2 sizes, if they are aired up proportionally the same. They are the same size (700) tire as each other.
 

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jrz1 said:
This leads me to a question I have always wondered. A 23 mm width would be more aero and lighter, thus faster except for the fact that a 25 mm tire of the same model usually will have lower rolling resistance. So.... which tire is ultimately faster the 23 mm with the lower aero drag and lighter weight or the 25 mm with the lower rolling resistance?
There's that weight issue too.
To me the rolling resistance issue is miniscule compared to weight.
25's are certainly more comfortable.
But if I'm planning a group ride with the big boys, 23's are the choice.
 

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It's simple physics and there are plenty of calculators online. The difficult part will be determining exactly how much the difference in rolling resistance is between a 23mm tire and a 25mm tire of identical construction. But how about this... just figure out how much of a change in rolling resistance would be equivalent to the massive 20g-40g weight difference on a 10% grade.
 
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