Racing on 23s vs. 25s

[Chris]

I have a team bike that rides pretty darn harsh. Was talking to our local bike shop owner and he suggested going to 25s over 23s and said that would make a bigger difference in the ride than switching from the oversized carbon stem that came with the frame or just about anything else. He said the guys at Cervelo describe it as a leaf spring and say that increasing the tire size will add to comfort and not impair performance except under very specific situations.

Thoughts?

[Erik.Lazdins]

I don't believe 25s are any slower rolling - VBQ did a tire test that found that the 25s had less rolling resistance.

The difference, I believe, is at higher speeds where wind resistance has narrow tires gaining a slight edge.

I went to 25s from 23s and don't miss the narrower tire ever.

[J.Greene]

I have a team bike that rides pretty darn harsh. Was talking to our local bike shop owner and he suggested going to 25s over 23s and said that would make a bigger difference in the ride than switching from the oversized carbon stem that came with the frame or just about anything else. He said the guys at Cervelo describe it as a leaf spring and say that increasing the tire size will add to comfort and not impair performance except under very specific situations.

Thoughts?

How much do you weigh and what pressures do you run?

The Michelin 23 prorace 2's are pretty fat already.

JG

[Chris]

6'2" 170lbs. Typically between 110 and 120.

[Big Daddy]

more specifics please.

frame/fork?
bar/stem?
seat post?
Wheels?

and as mentioned earlier, psi, your weight.

[J.Greene]

6'2" 170lbs. Typically between 110 and 120.

I'd say to ride the Michelin Prorace 2's in 23. I'm a lowly racer so I can't say this with authority, but I'd not ride 25's in a rr or crit. Too fat, don't need the extra weight, the tire and me.

Someone here will say to get in awesome shape and you won't even notice.

JG

[jhcakilmer]

What about 24s. The Vittoria Pave (tubular or clincher) are 24s, and very supple. I just bought my second set, and they very comfortable, fast, durable and I love the green sidewalls....very Flanders!!

I'd chose a tire with higher TPI, and softer casing, like the Vittorias.

[giordana93]

6'2" 170lbs. Typically between 110 and 120.


way too much pressure at 120. try 95-100. the irony is that even though high psi "feels" faster, it isn't. bouncing over every road bump instead of rolling through them is a bit like the ski racer catching air: it looks cool and fast, but is slower. the bigger tire suggested makes sure you have enough air cushion to avoid pinch flats at a lower psi, but if you run them upwards of 120 psi they won't be much if any better for harsh ride. 90 psi might be a bit low for your weight (need a more expert opinion on that one), but I don't think you would get pinch flats at 100 and maybe not even at 90-95. even different brands of tires will have a less harsh ride, so it pays to try some out. but start by seeing if you can get by with 90-100. it makes a big difference and only feels slower

[Fixed]

bro on my fix i have a 28 on the back wheel conti 1000 cost about 10 bucks it will not wear out and never flats (except now that i said that) . and a 23 mich pro race on the ft. but it on a steel frame and fork so the rides not a problem .
i don't notice any less proformance with the 28 on back as long as there is some air in it
i'd say give it a try why not ?
cheers

[inGobwetrust]

I'd say to ride the Michelin Prorace 2's in 23. I'm a lowly racer so I can't say this with authority, but I'd not ride 25's in a rr or crit. Too fat, don't need the extra weight, the tire and me.

Someone here will say to get in awesome shape and you won't even notice.

JG


Do you honestly believe the weight difference between a 23 and a 25 mm tire will make a difference in your race results? We're talking about the weight of a pencil, granted it includes the eraser as well......

I'll take the smoother ride every time.

[J.Greene]

Do you honestly believe the weight difference between a 23 and a 25 mm tire will make a difference in your race results? We're talking about the weight of a pencil, granted it includes the eraser as well......

I'll take the smoother ride every time.

Since the beginning of time racers have tried to race the best wheels possible, usually looking for light and more recently aero and light. Nothing has changed this week afaik. If comfort was the issue, and if I was going to ride 16mph, I'd use 25's-32's and a faster backwards kogswell. Well no I wouldn't, but I hope you see where i'm coming from.

JG

[Fixed]

the course can dictate the wheel and tire choice imho
cheers

[J.Greene]

the course can dictate the wheel and tire choice imho
cheers

yes

I raced 23's on the webster roubaix course and had no problems. Pretty stiff carbon frame to boot.

JG

[Fixed]

yes

I raced 23's on the webster roubaix course and had no problems. Pretty stiff carbon frame to boot.

JG
bro what do you use on those fast t.t.'s you do ?
cheers

[J.Greene]

bro what do you use on those fast t.t.'s you do ?
cheers

a hodge podge. A tubular 22mm continetal tub up front, and a 22mm Veloflex clicher on the rear. I wish I could rr like I tt. I am like a led sled bro.

JG

[Sasha18]

To answer the original question - yes, unequivocally, a change in your tires will increase your comfort more than a change is stem. The other answers suggest you might even be faster.

I would think 120 is too high.

The downhill ski analogy doesn't work for me. Isn't the reason it's less efficient because the skier comes out of the tuck position and is going out rather than down?

The "Jeep Effect" is the best description I've heard for why lower pressure is more effective. Rather than bounce along a road at speed, it's more effective to have the tires glued to the road constantly applying power in a forward motion. This is the same reason why rear suspension on a mtn bike is effective (I think).

[djg]

Well, why not try it?

For the same model (construction) tire, you'll gain a very small amount of weight and a very small amount of drag, but you'll also (potentially -- depending on tire pressure) drop a small amount of rolling resistance. What any of this will mean to you is really for you to say. I think that folks have gravitated towards 22 tubs and 23 clinchers -- most folks, most courses -- becasuse this tends to offer a good set of compromises, good handling, good road feel, good weight, etc. But people far better than I (I'm a qrap racer, so take this all with a grain of salt) change things depending on the circumstances. There's a road race coming up nearby that features a mile and a half stretch per lap that's unpaved and I'll be showing up with 24s (tubular) on my wheels.

We can post until the penguins come home, but really, you easily could try a set of 24s or 25s -- play around with pressure a bit in training and maybe a practice race or two and see what you think about the handling, comfort, etc.

[giordana93]

T
The downhill ski analogy doesn't work for me. Isn't the reason it's less efficient because the skier comes out of the tuck position and is going out rather than down?

I think you're right (it was my analogy), but I also thought part of it was that you leave the slick track of the snow and ice that are facilitating the descent. then again, I don't ski downhill much. on the other hand, I think everyone would agree that a bumpy road slows us down and that it is made worse by rock hard tires that would SEEM faster (and on a glass smooth track maybe are)

[J.Greene]

Well, why not try it?


good advice. I think we're trying to focus on one variable in a sea of them. I still don't see the point of racing on more than 23's unless the course is extreemly rough.

JG

[johnnymossville]

It's something I've been thinking about myself. I recently switched to much "softer feeling" tires and am glad I did, but they do feel slower to me. I suppose it may just be perception since things have smoothed out a lot over the rock hard tires I was running before. They are still 23's, but all 23's aren't the same width, they are definitely wider than the old ones.

I'm tending to think that just because it feels slower doesn't mean it is. Go with the 25's if they feel good for you. Or,.. find a softer riding 23 Like I did.

[palincss]

way too much pressure at 120. try 95-100. the irony is that even though high psi "feels" faster, it isn't. bouncing over every road bump instead of rolling through them is a bit like the ski racer catching air: it looks cool and fast, but is slower. the bigger tire suggested makes sure you have enough air cushion to avoid pinch flats at a lower psi, but if you run them upwards of 120 psi they won't be much if any better for harsh ride. 90 psi might be a bit low for your weight (need a more expert opinion on that one), but I don't think you would get pinch flats at 100 and maybe not even at 90-95. even different brands of tires will have a less harsh ride, so it pays to try some out. but start by seeing if you can get by with 90-100. it makes a big difference and only feels slower

If we're talking about Michelin 25mm here, 95-100psi for a 170lb rider is definitely too much. I'm over 210 and ride Axial Carbon 700x25s at 90 front 95 rear. They're nice and comfortable, and don't pinch flat. Initially I ran them up to 105 in back, close to 100 in front and they were much harsher.

[Sandy]

Qualification- Don't race. Never have. Never will. Too slow. Too old. Too out of shape. But, I have an opinion-

If you are a pro/cat 1/ cat 2 racer, then maybe 700x23 tires make sense to me. But if you do not have the most efficient (for you) riding position for the particular cycling discipline that you are racing, are not at your optimal weight, are not riding with optimal technique/ efficiency/pedal stroke/ conditioning/focus/ endurance/power/ strength/nutrition useage/group riding skills/etc. then why use 700x23 tires? What do they give you over 700x25? Very little.

1. The weight that you save using 700x23 tires is basically meaningless- For example, if I remember correctly, 700x23 GP 4000 tires weigh 205 grams and 700 x 23 GP 4000 tires weigh 215 grams. A difference of 10 grams.

2. Some studies have shown 700x25 tires to have less rolling resistance than 700 x 25. 700 x 23 have a longer narrower patch and a 700 x 25 has a shorter wider one.

3. The amount of force that is necessary to overcome air resistance in wheels/tires is really small compared to your bike's air resistance and much more importantly, your air resistance. The tire is a small addition to the wheel. The Chief gave an excellent analysis of rotating weight in a previous thread and I concluded that extra rolling weight is very insignificant overall.

4. Tires rolling resistance are measured normally, I believe, at reasonably high psi to maximize the results. But cyclists often choose a psi that is lower than what is used on tests, and the real world roads are not the smooth surfaces that tires are often tested on.

5. In the real world of roads, road adhesion is most important and a narrower tire with higher psi does not adhere to the road surface as well as a wider tire with less psi. The narrow one with greater psi will tend to bounce more and hence not give the more efficient forward motion of wider tires.

6. You use lower psi in a wider tire and hence you get a more comfortable ride- more supple, less bouncing, and hence you are not as tired and stay more efficient. I used 120/115 r and 110/105 f in 700 x23 GP 4000 tires, but now use 105 r and 95/97 f in my 700 x 25 GP 4000 tires- that weighing 190-230 pounds. Never had a pinch flat with the tires.

7. A 700 x 25 tire tends to stay planted to the ground better and handles better and more securely, especially the front end, at least as I perceive it.

8. Less flats with tires at a lower psi.

There is an advantage of the narrower tire- The aero advantage over the wider one as the narrower tire will be more flush with the rim whereas the wider one will stick out beyond the rim. But as stated before, that little aero advantage is almost meaningless compared to rider factors mentioned above.

So I think that unless you are a top notch racer efficient at most everything, riding at your optimal riding abilities,..., then the way to go is the wider tires. The narrow tires won't win you anything. Concentrating on cyclist improvement in areas above will.


Sandy

[swoop]

6'2" 170lbs. Typically between 110 and 120.

take 5 lbs out of your 23's .. report back.

[Chris]

take 5 lbs out of your 23's .. report back.

roger that

[swoop]

harm had me riding at 100 in back and 95 up front on michelin 23's. i thought he was crazy for how soft that is... but i didn't cost me any speed, gave me more in the corners, and made my arse look smaller in tight jeans.. so its all good.
when local knucklehead supreme slover confirmed that he runs at a lower pressure too.. that was it.. i was sold. and so.. there it goes.

[Chris]

What is Harm doing these days? Is he still with Toyota?

[swoop]

What is Harm doing these days? Is he still with Toyota?

no. moved on.... doing engineering work for some bike companies and is involved with the litigation end of equipment failure lawsuits and seems to love it... or something like that.
he's a guy that likes to think about how things work and why... and has a brain that processes things very quickly.
harm is a strong character.... you either really love the guy or you want to pull out your teeth around him. i love the guy.... and think he's great. i'm not sure that he and sean tucker were a good match!

[Tobias]

I don't believe 25s are any slower rolling - VBQ did a tire test that found that the 25s had less rolling resistance.Do you have a link to test data? It'd be nice to put in right context.

It's hard to tell between science and marketing. Bud makes best beer. Coors makes best beer. Miller makes best beer. Who do we believe? :crap:

[WadePatton]

Vertical deflection is what a non-compliant tire (high pressure) gives you. Lower pressures allow the tire to flex and absorb the small irregularities. The less the tire can flex, the more the bike and rider is going to be deflected. Vertical deflections are not forward motion. Larger tire, more volume, less pressure necessary.

Not a racer but I run 25's pretty low on pressure as 50% of my riding is on chip and tar type paving.

+1 on taking 5psi out.

[dookie]

Bud makes best beer. Coors makes best beer. Miller makes best beer. Who do we believe?

the folks who actually brew with barley and not rice/corn!

[Birddog]

Chris, FWIW, I ride Michelin PR2 23's at 95/105. There is quite a difference in ride quality since I deflated the 15 lbs a couple years back. I can tell no difference in speed, but then I don't have much of that anyway.

Birddog

[Grant McLean]

me riding at 100 in back and 95 up front on michelin 23's.

me riding at 90 front, 90 rear. that's plenty of air for me.
Don't know where this 120 psi advice got started.
That genie is hard to squeeze back into the tube

-g

[Peter P.]

Chris, it's time you experimented with tire pressure. Don't worry about tire width until you've done some homework with the 23mm tires you have.

I used to think high pressure was better, but all the chattering over pavement, even at 100psi., wasn't enjoyable. Of course, I had it stuck in my mind that if I dropped pressure, I'd go slower, so I never changed.

Finally, I caved and experimented. Each time I went out on a ride I dropped my pressure 5psi. per ride until I began to experience tire bottoming or a "squishy ride", then I upped the tire pressure 5psi. from there. I found that 90-95psi. is plenty for me; I enjoy good grip, no tire flex around corners, and I'm not bouncing around on rough pavement. It's really noticeable.

I think you run your tires way too hard, even at your weight.

[Fivethumbs]

I'm 6'3" and 190 lbs. I run Pro2Race 23s at about 95 front and 100 rear. They feel plenty pumped up to me and fast and smooth.