|notice any diff. b/t 700X23 and 700X20?||strosek|
Oct 4, 2001 3:54 PM
|Is there any noticeaable difference b/t 700X23 and 700X20?|
Oct 4, 2001 4:03 PM
|Your rims won't get dented as much if you run 23's.|
Oct 4, 2001 4:10 PM
|Rolling resistance, when pumped to rated pressure is about the same. 20s have a higher rated pressure, and so will have a harsher ride, which many falsely interpret as "being faster." 20s are slightly more aero. 20s are likely to have poorer traction because the higher pressure results in a smaller contact patch and a higher likelihood of "bounce" when you hit a bump. 20s are 15-20 gm lighter.|
|i'll never go back to 700X20s||bianchi boy|
Oct 4, 2001 6:17 PM
|after riding 700x23s. They just ride so much nicer, and supposedly their rolling resistance is no higher and possibly lower. I like the 23s so much that I'm tempted to try some 25s, but they're kind of hard to find.|
Oct 5, 2001 5:02 AM
|I got some 700x25's by mistake and put them on the Gios. They fit the chainstays. I really like them. There's not too much difference, but a little bigger tire helps on the country roads I ride on.|
|re: notice any diff. b/t 700X23 and 700X20?||Elefantino|
Oct 4, 2001 6:36 PM
|Garrett Lai, in Bicycling,wrote that wider actually has a smaller contact patch than smaller. Therefore, there is less rolling resistance in a 25 than tehre is in a 23 or a 20. There is an aerodynamic gain to narrower tires, though, which is why you don't see pros on 700x38s. |
Me, I just noticed that 20s have more of a jackhammer like bouncy-bounce feel to them than 23s. And the wheel guy at the LBS did warn of rim damage with 20s. He said pros ride 20s because they get free rims. Made sense to me.
|and the pros get free 20's, too [nm]||davidl|
Oct 4, 2001 8:24 PM
|re: notice any diff. b/t 700X23 and 700X20?||Woof the dog|
Oct 5, 2001 1:24 AM
|What the hell, I am 135 pounds or maybe less. I ride 20s in crits and everywhere and I have no f**** clue what are you talking about. Denting rims? You must ride in the woods to do that. No, 700x23 is not faster because 700x20 go to higher pressures and well make up for smaller contact patch. 140 psi in 20s would certainly be just as good as 120 psi in 23s. Yes, it is sketchier in the corners at 160, but at 140 its just right. I don't know about you, but I feel 23s too sluggish. Admit it, it IS about the feel. SUPPOSE I was slower on 20s at the same pressure. That would be something like 2 seconds slower I am sure. But that is why my vredsteins go up to 160s for a timetrial. Everywhere else doesn't matter. My airdynamic frame is actually made for 20cc tires. With 23s there is about 2mm of space from each chainstay, its rediculous. And stop reading Bicycling, its worthless. Got it?
Woof the dog.
|I second the Nix on BuyCycling Ragazine.||MB1|
Oct 5, 2001 6:20 AM
|Every time I buy one about 15 minutes later I wonder to myself "What the heck did I do that for? Nothing has changed from the last issue I wasted my money on."
I run fairly fat tires on all my bikes. I tend to take them off road every chance I get.
One exception, on my GT Edge Ti I use 700X20 front & rear-what a change in feel that is from my other bikes. Of course I'll take it off road too (with less satisfactory results).
|I think you're mistaken||Stew|
Oct 5, 2001 7:47 AM
|My recollection is that the column in Bicycling said that the contact patch volume remains the same and that it is the shape of the patch that changes. A narrower tire has a longer patch while a wider tire has a wider patch, which Bicycling says offers lower resistance. The conclusion is the same, but the reasoning is different.
Don't know if I buy it.
|re: notice any diff. b/t 700X23 and 700X20?||mickey-mac|
Oct 4, 2001 8:38 PM
|I agree with just about everything everyone else has said on the subject. I can't think of any good reason that anyone over 120 lbs should be on 700x20s. Come to think of it, I can't think of a good reason for anyone under 120 lbs to be on 20s.|
|More than that||Harry Hammer|
Oct 5, 2001 4:35 AM
|I am 210lbs - and this reason have been running 23 front and 25 rear. I used to ride 20s, then a pair of 23s - the comfort difference is huge, and am I any slower - not at all - the difference in the lines I take on corners around the course is far greater than anything the tyres will ever have to do with it. Try it, you'll be very nicely surprised, and I guess the rear will last longer too.|
Oct 5, 2001 4:53 AM
|My junior high woodshop teacher was named Harry Hammer (Bell Junior High). You're not him, are you?
|Yeah, is that you?||Harry Hammer|
Oct 5, 2001 5:01 AM
|Little Mikey M, who got his hand jammed to the bench with the hand drill and the chiesel stuck through his toungue?
No - not really - I think all junior wood teachers at called Harry Hammer. It's the bain of my life.
Oct 5, 2001 5:10 AM
|I wasn't very handy with the shop tools, but I managed to make it through the year without hospitalization. I didn't figure our Mr. Hammer was the type to be extolling the virtues of 700x23 tires over 700x20s. Welcome aboard!|
|slightly different feel.||jw25|
Oct 5, 2001 9:20 AM
|This is still subjective, but I recently picked up 2 pairs of tires, 1 set 20mm and 1 23mm. Both pairs are Hutchinson Reflex Golds (a very nice tire, too, and not that expensive).
The 23mm set was for training, and the 20mm's were for my TT wheels, to see if the change was faster or slower. My club has a monthly 10 mile TT, and I manage around 24:30's normally.
The 20mm's were slower, by about 40 seconds, and barring serious loss of fitness, it can only be due to rolling resistance. One problem with the tires is their max. pressure of 110 psi in both sizes. I might try overpressurizing the 20mm's, and have another go at the course, but it seems that the aerodynamic advantage, if any, is seriously overshadowed by the increased RR.
Like I said, this isn't the best test, but it's convinced me. Of course, these aren't true TT tires (the only TT competition I did, I used 23mm Conti GP Supersonics at 140 psi, and wow - that's a fast tire. I broke an hour on a 40K, with lots of rollers.)
Beyond that, I feel more confident on wider tires, as they seem to corner more stably. I haven't noticed much difference in comfort, but I'm on an older Cannondale, so it's not too comfy to start with.
So, given the choice, I'd opt for the 23's racing, and maybe even 25's or so for training.
|Hey did you get your handle from a Werner Herzog?||9WorCP|
Oct 5, 2001 9:49 AM
|Stroszek? Great great movie. No bikes. Just chickens in vending machines, mobile homes and ski lifts.|| |