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700x20 vs. 700x23: What's the difference???(11 posts)

700x20 vs. 700x23: What's the difference???kapalua
Jul 22, 2002 9:58 AM
I'm looking for a lightweight, high-performance training tire. Are there significant differences between these sizes?

3 millimetersTJeanloz
Jul 22, 2002 10:05 AM
The 700 x 20 should be lighter and have a harsher ride.

For a training tire, I maintain three criteria:

1. Cheap.
2. Strong/thick; when training I'd rather have more weight and fewer flats, I also want them to last a long time.
3. Width, wider is more comfortable. I wouldn't go narrower than 23, and I almost always train on 25s.
re: 700x20 vs. 700x23: What's the difference???cabinfever
Jul 22, 2002 10:21 AM
Yes, 3 millimeters is the difference. My personal opinion is that a 20mm wide tire is only necessary if you want the ultimate in rolling resistance (or lack thereof), and are a lightweight. For a recreational rider, I think a 20mm wide tire might give a harsher ride. I'm no expert though, so anyone with a differing opinion, please feel free.
re: 700x20 vs. 700x23: What's the difference???tronracer
Jul 22, 2002 10:36 AM
I never had any problems with 23's. I bought 20's by mistake and figured I'd try them beings I already installed them. I ended up with 2 pinch flatted tubes and eventually ran out of patches, had to call for a ride. I'm only 135lbs and I don't ride my bike harsh at all. These were continental gp3000 tires so they must be race specific. Never again. I ride 23's and love them.
re: 700x20 vs. 700x23: What's the difference???Geardaddy
Jul 22, 2002 11:05 AM
I ran a 20 on the front and a 23 on the rear for a long time and didn't have many problems with flats. I have since been running 23's with Michelin Axial Pros. It's a very smooth ride, and I don't feel as if I have lost anything performance-wise. However the Axial Pros have definitely been more flat prone than other tires that I used in the past.

I read somewhere awhile ago that there was very little advantage with clincher rims when going below 23's because of the way that a clincher tire deforms under weight causing there to be little difference in actual contact to the pavement, thereby little loss of rolling resistance. It is a different story with tubulars, where the deformity is different and going smaller than 23's is more worthwhile. BS? - who knows, but it seems to make sense.
Jul 22, 2002 11:47 AM
I've always ridden 23's but thought about switching to the 20. Thanks for your input...think I'll stay status quo.

Just a thought....Roadfrog
Jul 22, 2002 12:27 PM
If you are going to be doing a time trial or triathlon with aero wheels such as Zipp or HED... would it more sense to run 20's? Curious on your thoughts... HOP
Jul 22, 2002 2:03 PM
Apparantly using a tire that does not fit the shape of the rim you use creates some mean drag. A narrow, less round tire is best for aero wheels with narrow rims. A lot of serious TT/Tri riders also fill in the gap between the tire and rim with something (not sure what, a rubber compound maybe) to reduce drag as much as they can.
I use 20sgreg n
Jul 22, 2002 2:05 PM
The ride depends a lot on the quality of tire and max pressure.

I had some cheap but long wearing specialized tires (don't remember the model) that had a max pressure of 130 psi. They made for a pretty rough ride.

I've since been using Axial pros for training and racing and found the ride to be excellent. Very smooth and with a 110 psi max, it's not too harsh. In two and a half years of using 20s exclusively, I've only flatted twice, and once was because the tire was on its last leg and needed replacement anyway.
re: 700x20 vs. 700x23: What's the difference???DINOSAUR
Jul 22, 2002 2:45 PM
Tire manufacturers measure their tires differently. A 700x23 with one brand might be equivalent to a 700x25 in another. Sheldon Brown has an article about bicycle tires but I'm out the door and don't have time to look it up...
Got Rims?grzy
Jul 22, 2002 3:30 PM
On 20 mm you have a much higher chance of wanging a rim from hitting something. In the end they don't really corner as well but are a tad lighter. What are you training for and what are your objectives?