Road Cycling - does tire size really make that much of a difference??

I have a Bianchi Volpe, and the tires are a bit large for a racing bike. I haven't had any problems with them so far, and I have in fact never flatted...knock on wood. It's never been an issue before, but I am thinking about switching to a skinnier tire, and wonder if it really makes a difference. I am training for the Hotter then Hell Hundred in August, and I need to reach Hell's Gate which is 60 miles in, in about 4 to 5 hours. I average about 13-15 mph (on a challenging course...lots of hills) but I am worried I won't be fast enough. Granted HHH is flat, anyway. So tell it to me straight...does size really matter??

Yes, it does.

How wide are your current tires? If your racing on pavement then I would not go less than a 23 because any thing less then that there is no improvment due to sidewall deflection? Anyway continue to train on the wide tires than just before the race switch to a set of 23's. The wider heavier tires will give you more of a workout which should allow you to perform better when you race on the 23's.

How wide are your current tires? If your racing on pavement then I would not go less than a 23 because any thing less then that there is no improvment due to sidewall deflection? Anyway continue to train on the wide tires than just before the race switch to a set of 23's. The wider heavier tires will give you more of a workout which should allow you to perform better when you race on the 23's.

I'm running on 32's now...but I gotta say I'm almost scared to go too small, for fear of wiping out...is that a valid concern??

g'day,

you haven't said what size tyres you actually have?. I'll assume that its something larger than 23. The basic answer, (as with everything so i'm told...LOL), is that yes, size does matter. The larger the tyre, the bigger the 'envelope' of air it contains, more comfortable ride. Unfortunately, along with comfort you get 'mass' & 'road resistance'. You want a 'comfortable' ride?...go with 25 (or bigger!)...You want less resistance (ie be quicker)?....go the 20. The 20 's are normally extremely unforgiving & hard to get on & off the rim (tubulars). 23's are a good compromise between the 2. You will find alot of 'roadies' shod with 23's.When racing (in dry conditions), pump 'em up to the max your wheel is rated for (don't worry to much about what the tyre says),

cheers,

Hitchy

It’s a common misconception that wider tires have more rolling resistance. In fact, wider tires have less rolling resistance given the same tire pressure and sidewall stiffness :eek: Here’s why:

The contact patch of a tire is a function of pressure in the tire, weight on the tire and sidewall stiffness. With bike tires, sidewall stiffness is not a major factor so with 200lbs of rider/bike weight and 100 psi of tire pressure, the total contact patch will be ~2 square inches for both tires.

The narrow tire will have a longer, thinner contact patch than a wider tire. The result is more tire deflection with the narrow tire. This added deflection causes friction, heat and, ultimately, more rolling resistance.

The counter to this argument is that narrow tires can (and should) be inflated to higher pressures. This will indeed lower the rolling resistance, but sacrifice comfort. The higher pressure won’t have as much advantage on bumpy terrain, though, since the bouncing around is sapping forward momentum.

The main downsides of wider tires are the added weight and air resistance. Added rotating mass is especially bad since you have to accelerate it twice when leaving a stop sign (straight ahead and rotationally).

Assuming your rims are compatible, I would go down to at least some 25’s. Personally, I ride 23’s and I haven’t had any problems.

-murray

I'm riding 32's now, would a 25 be compatible on my rims? Or is this a question for a bike shop?

I'm riding 32's now, would a 25 be compatible on my rims? Or is this a question for a bike shop?

ok...700x32/30c Now I'm not entirely sure what that means...but at least this will give you the correct info!!

ALSO...do any of ya'll have opinions on the "air free" tires...never flat etc.

I don't think you can install 23 or 25s on the Volpe's rims, 'cause I have the Volpe and only allows down to 28. Keep a mind that the Volpe is a light touring bike (a "truck" bike), don't expect high performance, speed wise out of a Ford F150 so to speak.

Corsaire

The main downsides of wider tires are the added weight and air resistance. Added rotating mass is especially bad since you have to accelerate it twice when leaving a stop sign (straight ahead and rotationally)

Having more weight on the periphery of a wheel should enhance the wheel's flywheel effect, no? I agree that a lighter tire will make a wheel easier to accelerate from a stop, but is this a noticeable handicap during a long ride with few stops & starts?

BK

Having more weight on the periphery of a wheel should enhance the wheel's flywheel effect, no? I agree that a lighter tire will make a wheel easier to accelerate from a stop, but is this a noticeable handicap during a long ride with few stops & starts?

BK

You’re right, with no starts and stops, it shouldn’t make much difference. OTOH, bike weight shouldn’t make much difference except on hills. The fact is most of us ride on hills and our speed various, even on long rides.

Does it make a difference? I don’t know, but I’m reasonable sure Lance could win the Tour on a 25 lb bike. For no extra cost, I’ll take 23’s over 32’s any time! If nothing else, the bike will feel much lighter when I stand on hills.

-murray

For no extra cost, I’ll take 23’s over 32’s any time! If nothing else, the bike will feel much lighter when I stand on hills.

-murray
The bike will feel lighter, no doubt. It might even feel faster. Will it significantly shrink your transit time? That's the question. I need to google this.

Peace
BK

I have a Bianchi Volpe, and the tires are a bit large for a racing bike. I haven't had any problems with them so far, and I have in fact never flatted...knock on wood. It's never been an issue before, but I am thinking about switching to a skinnier tire, and wonder if it really makes a difference. I am training for the Hotter then Hell Hundred in August, and I need to reach Hell's Gate which is 60 miles in, in about 4 to 5 hours. I average about 13-15 mph (on a challenging course...lots of hills) but I am worried I won't be fast enough. Granted HHH is flat, anyway. So tell it to me straight...does size really matter??

Actually, Hells Gate closes at 12:30 so with a 7:00 AM start, you have 5 1/2 hours to get there. That works out to 11 mph average speed (elapsed time, not ride time) so if you are a 15 mph average rider you should not have any difficulty beating the gate.

I have a Bianchi Volpe, and the tires are a bit large for a racing bike. I haven't had any problems with them so far, and I have in fact never flatted...knock on wood. It's never been an issue before, but I am thinking about switching to a skinnier tire, and wonder if it really makes a difference. I am training for the Hotter then Hell Hundred in August, and I need to reach Hell's Gate which is 60 miles in, in about 4 to 5 hours. I average about 13-15 mph (on a challenging course...lots of hills) but I am worried I won't be fast enough. Granted HHH is flat, anyway. So tell it to me straight...does size really matter??

Not only are the Volpe's tires wide, they are also relatively low pressure and knobby. I suggest trying some Panaracer Pasela 700x28s. They are narrower, smoother, and higher pressure than what you have and they'll fit your rims. You can get them for around $15 each, sometimes less, and that's not a bad amount to spend on an experiment. I think you'll notice a difference.

How big a rider are you? I have a preferance for 23's (150lbs rider) my buddy likes his 26's (230lbs rider). get the bike set up so it is comforatable and don't worry about what any of us the you.

if you can find a way try test riding a bike with thinner tires to see if you want them...
i went from 25's to 20's and i dont find it to be that much harsher...when i was looking for tires everybody told me to get 23's...i went with my gut and i love my 20's.
i guess my point is if you have a gut feeling you will like something go with it rather than going with what everybody else has.

I would go with the 28's at the biggest and 25's at the smallest. Just make sure you lose the 32's

20's are too small and do not protect your rims enough and will be flat prone

20's are too small and do not protect your rims enough and will be flat prone

not true...ive never had a flat (ever in my life)...ive ridden the 20's for this whole season so far and not one flat. and its not because i ride carefully either...im a bit of an idiot sometimes when it comes to potholes (ill dodge the little one and hit the big ones).

How big a rider are you? I have a preferance for 23's (150lbs rider) my buddy likes his 26's (230lbs rider). get the bike set up so it is comforatable and don't worry about what any of us the you.

I recently switched from 25's inflated @ 110-120psi to 23's inflated to 140-150 and there is a BIG difference in rolling resistence between the two. Granted, I weigh 225 lbs so you may not notice as much difference if you weigh 160 lbs... The 23's when pumped up to 150 psi feel basically like they are made of oak - not quite steel, but they are very hard! I have a carbon frame which damps out some of the harshness. There is a tradeoff of traction versus rolling resistence when you increase pressure, which is why I usually inflate my front tire at a lower psi than the back. I am tempted to inflate my rear tire to 160psi (which is the max for my pump) just to try it. My tires list their max psi as 145, but I bet they are conservatively rated. I think you could inflate them to at least 200psi without them exploding or blowing off the rim. LOL At some point you get to the point of diminishing returns...

If your running a 32 now and that was the original size that came on the bike new then you either have a 15, 17 or 19 mm wide rim (measured from inside), more than likely a 17 since that is middle of the road for a 32 tire. If you have the 17 then the narrowist tire you can have is a 25. If it's a 19 then the narrowist will be a 28. I doubt it's a 15, but if it is you could go to a 23. You can find a good selection of light racing or training tires in a 25 size-28's gets a bit harder to find.