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23s to 25s - how much slower?(11 posts)

23s to 25s - how much slower?SFgeek
May 22, 2002 9:32 AM
I switched out my 23s with 25s to see if it made for a better ride in the city. Much to my dismay i found that I was incredibly slow this morning. Is it the extra rubber slowing me down or is it the hangover?
re: I'd bet on hangover, traffic, or a dragging brake shoe.dzrider
May 22, 2002 10:06 AM
I find the difference between 23s and 38s with Mr Tuffy to be about 2 or 2.5 mph. Not what I would call incredibly slow and a much bigger difference in weight and friction than you're talking about. Your opinion may be different.
re: 23s to 25s - how much slower?Woof
May 22, 2002 10:21 AM
23c is faster than a 25c because its narrower, thus having better aerodynamics.

Peace

woof the dog.
re: 23s to 25s - how much slower?jkoshi
May 22, 2002 10:28 AM
while air friction might be a feasible speed argument for a helmet or a parachute, I'm not entirely convinced that it is what will slow down a fatter tire. faster is a relative term really. faster than what? faster around a corner? I'd bet that I can corner faster on a 25 than a 23 in equivalent conditions. a single factor does not a faster rider make. cheers.
re: 23s to 25s - how much slower?Woof the dog
May 24, 2002 10:29 PM
whatever man, there is a reason pros use narrow tires for time trials, right? In corners 25 and 23 cornering would be indistinguishable. It really all depends on your tire pressure and how worn it is. All tires start slipping at a little bit less than 45 degrees just because the way the rim and the tire work together. Duh. Aerodynamics certainly do matter a whole lot. Why do you think track riders often use rear disks and the likes of Hed for the front wheel? Isn't track supposed to be about acceleration? Hell yeah it is. I think, with superior aerodynamics, you will be basically gaining more and more for what you've spent on accelerating that presumably heavier wheel. If you want to break away in a road race, a narrow tire with high psi would help. Just from a personal experience, you would certainly be faster. I'd even tend to say that what you would lose in corners you'd gain in saved energy. Criteriums is a different matter, but 25 vs. 23? please!

I found this great discussion, and I posted it already in some other topic on this forum.
http://www.cyclingforum.com/forums/Index.cfm?CFApp=2&Message_ID=7611

Sincerely

Woof the dog.
re: 23s to 25s - how much slower?Woof the dog
May 24, 2002 10:30 PM
i think i probably meant to say "more than 45 degrees" although I don't remember, maybe I was right the first time. Who cares anyway, you get my point

Woof, the bee
First Q - same tires?jw25
May 22, 2002 12:42 PM
and second - hangover? Yeah, that'd slow me down.
Seriously, though, for the same tire, there should be minimal differences in speed. It's a pretty minimal difference in size, and assuming pressure was reasonable, the 25 might be slower, but it's hard to say empirically. 23 seems to be the standard for racing due to weight, rolling resistance, and pinch-flat resistance. Bigger is heavier, and smaller flats too easily.
Give them a try sans-hangover, and I think you'll be happier.
re: 23s to 25s - how much slower?SFgeek
May 22, 2002 2:30 PM
different tires...

23s - Vittoria Action HSD
25s - Vittoria Rubino Intrepid TT

i had to have been the hangover that made the difference in speed so noticible.
IF same tire, difference is minimalKerry
May 22, 2002 4:23 PM
For the same tire construction, the wider tire will have a lower tire pressure, but will also deflect less to create the tire patch. It is tire casing deflection that is responsible for the majority of rolling resistance. So, there would be minimal resistance difference between a 23 and a 25 IF they are the same brand/model (and therefore the same casing construction).
I'd be surprised if it's tires.retro
May 23, 2002 7:12 AM
I've switched back and forth among 23s, 25s, 28s, 32s and 35s on my commute for years, and I don't see enough difference to measure consistently. The 35s FEEL slower, but when I look at comparative times (for a ride I've done regularly for 20 years), there's really not much change. I'd guess it's a different brand of tire, a difference in pressure, a bad breakfast or maybe just a bad day before I'd blame it on a 2mm nominal increase in tire width.
re: 23s to 25s - My 28's are the fastest.snuggleman308
Jul 3, 2002 3:38 PM
I've tried 20mm, 23mm, 25mm, 28mm, in various brands. 20's FEEL fast but really aren't (IMHO) on REAL roads, as I tend to have to slow a bit through rough-paved areas. On 28's I just roll (blast ?) right through.