Difference between 20c and 23c tires?

foggy10 said:

I'm currently using 700 x 23c tires, which are pretty standard I think.

However, I'm confused now as to whether I can use a 20c tire on my wheel/rim.

What's the difference? Is 20 vs 23 thinner or something? Are they compatible? Confusion...

You probably shouldn't use 700x20 tires if your rims are larger than 622-13 ...

Actually, some people might say that you should never use 700x20 tires -- the disadvantages outweigh the advantages!

The 700x23 has about 15% (?) more volume than a 700x20 tire ...

If you feel compelled to using 700x20 tires (the "obvious" advantage is less weight), then you should probably consider using sew-ups.

20c tires are not used by that many racers in road race conditions.

If you are doing a TT 20c are quite common.

23c are light enough for most conditions. If you are just training and not racing I'd even look at 25c.

Also not all 23c tires are equal. Some are more narrow.

Good luck.

20s are more likely to slide out during a tight corner in a crit. Weight diff is minimal to the average rider.

Assuming we are talking the same type of tyre, then 20c would be slightly more aerodynamic, where 23c will have slightly lower rolling resistance and be a lot more confortable.

On conventional road surfaces, the disadvantages of using the 20c out weigh the advantages and most riders use 23c.

yeah, what they ^ said

I used 20mm tyres at 150psi for years before I came to my senses. 🙂 I always assumed the fastest tyres were the skinniest and hardest, but I was way wrong, especially for most road surfaces.

23s absorb small bumps better (with the right pressure), which is why they're faster; they corner and grip much better, and they're more comfortable.

alfeng said:

The 700x23 has about 15% (?) more volume than a 700x20 tire ...

If you assume the cross section of a tire is round then the 23s have 32.25% more volume than the 20s.

I use 20mm tyres for racing(Michelin Carbons) only and 23 for training(Michelin Carbons on Megamiums).

I find 20mm fine. The roads I race on are a coarse chip and for some races there is gravel/potholes(few) and sometimes railway tracks to cross. Sometimes it's raining.
I've never had a problem with them🙂 .

The may feel harder to ride on than my 23s but I usually put about 10psi more air in and in the heat of racing I usually don't notice it.

The feel faster but then they're only used with my race only bike which is "faster"(depends on me really) than my training bike(s).

For what it's worth, I use 20mm on the front and 23mm on the rear wheel, both Michelin Pro2 Race. I don't think it really buys me anything compared to a standard 23mm setup, though... 😎

Dietmar said:

For what it's worth, I use 20mm on the front and 23mm on the rear wheel, both Michelin Pro2 Race. I don't think it really buys me anything compared to a standard 23mm setup, though... 😎

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Quicker steering....nah🙂

All things being equal, a bigger tire, i.e, 25mm vs. 23mm vs. 20mm, will buy you more comfort which will, over the course of a long ride, mean that you can perform a bit better. Somewhere, someone did a study and found that when lower rolling resistance and best aero performance were considered, 23mm tires offered the best solution. 20mm tires have comparitively [censored] rolling resistance but better aero properties. 25mm tires will have the best (i.e., lowest) rolling resistance but will also have more aero drag than 23mm tires.

I use 25mm tires on my clincher wheels. Can I tell a difference in how fast I ride compared to when I used 23mm tires? No. Can I tell a difference in comfort? Yes.

My tubulars are 21mm tires. They do ride a bit more harsh than the 25mm tires. Performance difference? I can't say: the 25mm tires are on 20mm rims, while the 21mm tires are on 46mm CF rims.....and I can't seperate out the aero benefits of the rims from the aero and RR benefits of the tires.

One place where a larger tire can make a huge difference is in the size of the contact patch. Obviously, as the tire gets larger, the size of the contact patch gets larger since the larger tire will be inflated to a lower pressure. The amount of friction provided by a larger contact patch is proportional to the size of that contact patch (in area) and thus also to the pressure. So if one tire allows you to run a pressure at 110 psi, whereas a larger tire allows you to run at 100 psi, then the larger tire will provide 10% more friction than the smaller tire (assuming the same coefficient of friction for the tread compound). This can be a HUGE difference when cornering at high speed or when cornering in the wet. For a given corner and given bike/rider weight, this translates to being able to corner with a speed that is roughly 3% faster.