Bicycle Mechanics - Slick vs. tread tires

As an example, Continental Top Touring 2000 tires compared to say a Schwalbe Marathon slick. If the tires are the same size (700c) and comparable weight, is there THAT much difference in rolling resistance. I know there is a large difference in a mountain bike knobby tire vs. a slick but that is more extreme than what I am talking about. The roads in my area are mostly chip seal and I have been using tires like the Top Touring 2000. I would like to use something with less drag if it makes alot of difference. Thanks, Rich

As an example, Continental Top Touring 2000 tires compared to say a Schwalbe Marathon slick. If the tires are the same size (700c) and comparable weight, is there THAT much difference in rolling resistance. I know there is a large difference in a mountain bike knobby tire vs. a slick but that is more extreme than what I am talking about. The roads in my area are mostly chip seal and I have been using tires like the Top Touring 2000. I would like to use something with less drag if it makes alot of difference. Thanks, Rich

I tried precisely the switch from TT 2000 to Marathon Slicks, finding that the latter gave me a flat about every 1K mile per tire. The flats were caused by stone chips! At the same time, I was getting >7k of service per TT 2000 w/o a flat! After the couple of times I had to fix a Marathon Slick on the road, I gave up on any resitance gains and placed those tires straight into retirement. With several different tires I have tried, I found systematic differences in terms of the frequency of flats. Right now, I am riding both TT 2000 and Marathon XR and again begin to forget what a flat is. Your priorities and details of your riding environment may be different, but myself I won't be trying to thin my thread anytime soon.

the point is moot if you use tuffies. what application?

As an example, Continental Top Touring 2000 tires compared to say a Schwalbe Marathon slick. If the tires are the same size (700c) and comparable weight, is there THAT much difference in rolling resistance. I know there is a large difference in a mountain bike knobby tire vs. a slick but that is more extreme than what I am talking about. The roads in my area are mostly chip seal and I have been using tires like the Top Touring 2000. I would like to use something with less drag if it makes alot of difference. Thanks, Rich

You can ignore rolling resistance. It is a fairly meaningless thing. It is one of those things that can be measured but it so subtle you can't notice any difference in use. Tread has no meaning on a bicycle tire either. You can have tread or not. Makes no difference. Personally, I would suggest buying tires for other reasons - weight, durability, color, sale price, whatever. In my own experience I have gotten 1000's of miles without flats from Vittoria Rubino, Michelin Carbon, Michelin Pro 2, Vredestein Tri Comp. The Rubinos and Carbons are a little heavier and cheaper than the others. All have performed with excellence. I'm sure there are all kinds of other bike tires that will perform comparably - perhaps the same ones you are talking about. I just don't have experience with them myself.

the point is moot if you use tuffies. what application?


I have not tried Mr. Tuffy liners, but, according to experience of many people, ends of those liners produce flats themselves. My take on this is that those liners presumably reduce flats for lower end tires but are detrimental when used with higher quality tires.

You can ignore rolling resistance. It is a fairly meaningless thing. It is one of those things that can be measured but it so subtle you can't notice any difference in use. Tread has no meaning on a bicycle tire either. You can have tread or not. Makes no difference.

Ditto here. I barely notice any speed difference while commuting (20 miles) on road ‘dale with 23mm bold Michelins than 32mm knobbied nokkians on the Kona cross bike, maybe seconds? Who really cares if you are not racing. ;)

Wind drag makes alot more difference than tire rolling resistance, which you can minimize by increasing pressure.

I have not tried Mr. Tuffy liners, but, according to experience of many people, ends of those liners produce flats themselves. My take on this is that those liners presumably reduce flats for lower end tires but are detrimental when used with higher quality tires.

Installed properly, Tuffies prevent flats. After a few hundred miles, they begin to lightly stick to the inside of the tire. I don't buy the bit about detrimental with higher quality tires. But then again, people use higher quality tires to race, and racing with tuffies is stupid.

When using tuffies place duct tape on the overlap part of the liner. Also I find it is most serviceable to contact cement the liner onto the tire by sanding the liner side that will contact with the tire. By doing this the liner will not shift and stay centered and will stay in place when you do take the tire off. Works for me.

The main factor that gives one tire lower rolling resistance over another is flexibility. If a tire flexes when faced with a bump/deviation rather than inducing vertical motion then it prevents the wasting of energy and therefore rolls better. An added benifit is that these tires that flex also have a better ride. Now thin, flexible tire aren't always the sturdiest but then again if the tires well made it can be flexible AND puncture resistant and road tires such as Vredestien Fortezza's do just that where as cheap, heavy tires can be slow because they don't flex yet are easily puntured as well.

I find that its worth paying for good tires. Check out the Vredestien Perfect Moiree tires it you can find any. They look like a very good alrounder to me. http://www.vredestein.com/Fietsbanden/Index.asp?UserSessionID=82894099

Regards, Anthony

I think the term is supple. The casing that's supple will deform only at the point where it rolls over a bump or imperfection and doesn't deform much more of the casing than that. This results in less frictional-losses and heat-buildup, thus less rolling-resistance. Thick stiff casings will deform a larger area on teh tire and have higher-rolling resistance. Kinda like the comparison between newer radial auto tyres vs. the old-style bias-ply tyres. Now you can have a thin supple/flexible sidewall for fast-rolling, yet a thicker tread for puncture resistance.

As for rolling-resistance between types of tread, slick or herringbone or fine-grid, forget it, it's a minute different.

Tuffies don't cause flats! It's when people try to be neat and trim the overapped ends to a minimum that it causes flats (saves 1gm though). The ends are tapered and rounded out of the box, if you cut the ends, they'll have a sharp 90-degree step and be sharp. They do increase rolling resistance though... how much, I have no idea, we'll have to do an experiment...

You can ignore rolling resistance. It is a fairly meaningless thing. It is one of those things that can be measured but it so subtle you can't notice any difference in use. Tread has no meaning on a bicycle tire either. You can have tread or not. Makes no difference.

I agree somewhat when you're comparing different brands of the same kind of tire with similar treads. But I can tell you I feel a huge difference between the 26x1.5 road tires I mount in the summer and the 26x2.5 low-pressure knobbies I mount in the winter: when spring comes and I finally shed the knobbies, it feels like I just fixed a dragging brake pad. So rolling resistance is very much more than subtle, it's just the difference between rolling resistances of similar tires that's subtle.

Wind drag makes alot more difference than tire rolling resistance, which you can minimize by increasing pressure.

Weally? how much pressure do you need to overcome...or minimize wind drag? would 200 psi minimize it? you cant increase pressure and expect a major difference in wind drag if any; its the tires surface size that has any effect on that, and increasing pressure wont change that only buying narrower tires will do that. and lighter tires will also decrease rolling resistance.

In fact increasing tire pressure can cause more rolling resistance, or perhaps more accurately slow the tire down more since the tire then will begin to skip over road imperfections like the chip and seal the poster rides on.

When using tuffies place duct tape on the overlap part of the liner. Also I find it is most serviceable to contact cement the liner onto the tire by sanding the liner side that will contact with the tire. By doing this the liner will not shift and stay centered and will stay in place when you do take the tire off. Works for me.

huh? duct tape? what is duct tape the answer to all problems? well not in this case! the overlapping part of the liner needs to be sanded so the taper will be paper thin at the edge. if all you do is duct tape the ends you haven't really done anything, the edge can still chaff the tube. also the lighter the tube, ie thinner or racing tubes, the more likely the tuffy will chaff a hole in the tube. also you do not need to cement the liner in place, the liner will naturally adhere to the tire after awhile, and by not cementing in place it can be easily removed and reused.

I'm not sure I buy your statement, freako, that more pressure could slow a tire down - well, not until you manage to blow it out with too much pressure.

Skipping over road imperfections might be the negative consequence of too much pressure in a tire (I don't know, but I suppose that might be true). Then, again, that is a different issue all together than rolling resistance.

Also, someone correct me if I'm wrong. I thought softness and flex in a tire would tend to increase its rolling resistance. Some here are stating just the opposite. I would think that solid steel tires would have less rolling resistance than rubber. Wood tires also would have lower rolling resistance. Obviously, these substances would be heavy and very uncomfortable, and probably give you terrible traction. But they would have lower rolling resistance.

Am I correct, or am I full of #$%?

Caruso

When I bought my Cannondale 'cross/disc, I had them take the quasi stock 'knobbies" off and put on narrow Armadillo slicks. I have run a similar tire on my 27" Schwinn for many years - never have I experienced a flat.

So far, the same has been true for the tires on my new bike. They have a much lower profile than the tires on my Schwinn. I didn't give any consideration to how much those tires weigh. Are there other tires not prone to flatting that I should consider.

In the over all scheme of things, tires (really good ones) don't seem to be that expensive.

I use to religiously pump my tires to no more than 115psi, but, have lately (after reading some posts on this board) tried slightly higher pressures - 120-130 psi. Bike seems a tad faster - and I notice no discomfort - so, I'm sticking with the higher pressure.

Caruso

Also, someone correct me if I'm wrong. I thought softness and flex in a tire would tend to increase its rolling resistance. Some here are stating just the opposite. I would think that solid steel tires would have less rolling resistance than rubber. Wood tires also would have lower rolling resistance. Obviously, these substances would be heavy and very uncomfortable, and probably give you terrible traction. But they would have lower rolling resistance.

Rolling resistance comes from a phenomena in wheel materials called hysteresis. To make things simple, the way a tire works is this: when a section of tire comes in contact with the road, its surface, and the shape of the tire/wheel underneath, is deformed and compressed. That takes energy. When the section of tire leaves the road, the tire/wheel recovers its initial shape and releases the energy stored in the deformation process by "pushing the road down" so to speak. Since you have a leading section of tire coming in contact with the road and the trailing section leaving the road at all time, the forces cancel each other and the wheel is seen as rolling with very little resistance.

Now what causes a tire to drag is this: when a tire is forcibly deformed, it has no choice, it deforms. But when it regains its shape, there's a sort of inertia due to the friction in the rubber material, and due to the density of the rubber, that makes the tire regain its shape with a slight delay, so that the tire doesn't "push the road down" immediately as the compression force ceases, effectively wasting part of the energy that was initially put into the deformation.

That's why the most efficient tires have walls as thin as possible: air has virtually no hysteresis, so by reducing the amount of rubber separating the atmosphere and the compressed air in the tire, you decrease the overall drag of the tire. That's also why airless tires, despite being very hard, drag like pigs (they waste up to 30% of the pedaling energy). But of course, there's a balance between too thin a tire (that blows at the slightest thorn) and an airless tire that steal all your energy. There are also rubber compounds that produce more or less hysteresis, so all tires aren't born equal for a given shape.

And of course, another, lesser source of drag is the heating of the rubber due to constant deformation, which is also why a high pressure tire performs better because it deforms less. As for solid steel wheels, yes, they're virtually perfect as far as drag is concerned, but you wouldn't ride 100 yars with them without falling down :)

Weally? how much pressure do you need to overcome...or minimize wind drag? would 200 psi minimize it? you cant increase pressure and expect a major difference in wind drag if any; its the tires surface size that has any effect on that, and increasing pressure wont change that only buying narrower tires will do that. and lighter tires will also decrease rolling resistance.

In fact increasing tire pressure can cause more rolling resistance, or perhaps more accurately slow the tire down more since the tire then will begin to skip over road imperfections like the chip and seal the poster rides on.

Of course, the impact of tire pressure on drag can be practically ignored. Otherwise, however, the drop in rolling resistance with increased pressure is well documented:

http://bike.terrymorse.com/rolres.html

http://www.schwalbetires.com/tech_info/rolling_resistance

2 i:
The second link was very informative - thanks. I could not get the first link to open. It timed out on me.
Caruso

Here's a good article by Jobst Brandt, author of "The Bicycle Wheel" on tyre tread patterns: Tyres with smooth tread (http://draco.acs.uci.edu/rbfaq/FAQ/8b.13.html)

Seems Terry's server isn't working, the link is similar to the one at Analytic Cycling and uses a chart from Brandt's rolling-resistance test: Tyre Rolling Resistance (http://www.analyticcycling.com/ForcesTire_TireRollingResistance.html)

Do this simple test and you will have the answer about tire pressure.
Pump the tires at about 60-70 psi.
Ride your bike for a few minutes around the house.
Now pump the tires at 100psi and ride again.
Pump to 120 psi and ride again.

I did and at 120psi was muuuuch easy to pedal.

http://sheldonbrown.com/tires.html#tread

Of course, the impact of tire pressure on drag can be practically ignored. Otherwise, however, the drop in rolling resistance with increased pressure is well documented:

http://bike.terrymorse.com/rolres.html

http://www.schwalbetires.com/tech_info/rolling_resistance

Where they come up short in the second analysis - at least according to the engineers at Zipp is that after a certain point of inflation, there is no more lessening in rolling resistance. I had a long discussion with them trying to decide the tire pressure (tubeless) I wanted to run my Zipp 999 wheelset at for racing time trials. I had been running about 145 lbs. According to a study made, I am waisting arm motion pumping beyond about 120 psi.