Road Cycling - How wide are your tires?

How wide are the tires that are currently on your road bike?

Mine are 23mm

23

23

28 on one, 32 on the tourer and 1.75 on the commuter, 2.25 on the mtb, 23 on the road bike when i race

23 on the front and 25 on the rear.

As I have posted elsewhere, I recently tore up my shoulder roto cuff in a bike crash. And I do not understand why, everything seemed stable.
So in the phase where, I am still a cycle addict, but a little gun shy- I have been favoring my bikes with wider tires. Hybrid I am now favoring have 38's over my normal 23's.
Think 38 is more stable? Maybe I change out my 23's for 28's on my road bikes, I will feel I have done something to make me feel more secure.
My road bikes are 23's, my touring bike is 32, I think and my hybrid is 38.. While riding with this gimp arm I favor the 32 or 38. Think bigger tires are more stable. I traveled at least 50,000 miles on usually 23's before this unexplained crash.

23's on my c'dale and 25 on my trek which is my rain bike.

28 on the Fuji, 32 on the Airborne, 35 on the Novara (rain bike)

23

My question is, why do wider tires provided more grip (look at cars, Ferraris have like 275 tires and Tercels have 145s). Mathematically, it should have no effect.

25



Wow, looks like most roadies are riding 23s. Is there an advantage for 23 over 25?

I'm riding 22 for my primary tires (conti sprinters).
I do have some 25's that I use for the trainer and
for really crappy roads.

Marty

Spier.. Maybe more inportant to stability is type of tread.

700x23 c on my cinelli

old school 27inch x 1 1/4 on my motobecane commuter :)

Originally posted by Spire
My question is, why do wider tires provided more grip (look at cars, Ferraris have like 275 tires and Tercels have 145s). Mathematically, it should have no effect.

But mathematically it *would* have an effect.

the ammount a tire can hold in lateral force is an equation whereby one has to work out all the physics vectors.

The basic is that any down force causes the tire to stick better, and side forces make it try to slip.

In any given situation the forces on the tire will be the same, but you can make the car stick better by upping the size of the rubber patch. The downforce per square inch will go down, but the overall coefficient of friction will increase enough to overcome that.

In other words, the bigger the contact patch, the more sideways force a tire can resist in dry conditions.

Once you get water or mud or any other complication in there things get completely different!

I'm not an engineer, so I hope i got this right and don't embarass myself.

peas,

Jester

Cadd - 23's weigh a bit less, is all. I've thought of going to 25's, but can't think of any reason to do so as I am comfortable on 23's and have always been so. Even banging into some pretty vicious potholes I've not suffered either pinch flats or rim damage. So have stuck with the 23's.

i got 20's for my fixed gear bike; i hope they won't destroy my butt/rims. i'll go 23 if it's too rough.

20s for me.

I've put down 23 because that's what I ride primarily. One the cyclocross bike that I ride on non-technical single track, fire roads, and for my commute I have 28's.

I find that with the quick release that 25s can be hard to get out between the breaks. When I was using 25s on my commuter, that just got a bit annoying. So when I replaced them, I replaced them with 23s. I don't actually notice much difference in terms of road handling though.

23

25, it comes on my bike, bontrager race lite. There's no thread though, wonder if that's going to affect grip.

I have 700x27 Rivendell RolyPoly on my road bike. I would run wider tires but my short reach brake calipers don't have enough clearance for that.

Originally posted by jester69
But mathematically it *would* have an effect.

the ammount a tire can hold in lateral force is an equation whereby one has to work out all the physics vectors.

The basic is that any down force causes the tire to stick better, and side forces make it try to slip.

In any given situation the forces on the tire will be the same, but you can make the car stick better by upping the size of the rubber patch. The downforce per square inch will go down, but the overall coefficient of friction will increase enough to overcome that.

In other words, the bigger the contact patch, the more sideways force a tire can resist in dry conditions.

Once you get water or mud or any other complication in there things get completely different!

I'm not an engineer, so I hope i got this right and don't embarass myself.

peas,

Jester


One correction; The coefficient of friction remains the same. It is independant of contact patch size and is purely a function of cohesive forces between the tyre and the road.

But mostly your ideas are correct;
High performance cars have larger tyres not only so that they can increase the contact patch size but also so that the shape of the contact patch can be improved.
The bigger surface area does help because you will have more tyre material in shear, resisting the centrifugal force of teh car wanting to spin out of the corner. This reduces the stress on the tyre compound and also improves heat dissipation.
Wider tyres are also needed to provide sufficient tyre volume to absorb the heat energy generated by rolling resistance

Road Bike 23
Mt. Bike 1.9

27 x 1 1/4 on 1975 Schwinn approved Voyageur II, which is what the rims call for.

John Hawrylak
Woodstown NJ