Changing to slick tires on MTB

[Vishnu Janardhanan S]

Dear All,

I have a Schwinn frontier sport and its tires are Innova Trail, 26 x 2.0
I commute to office which is like 20km(10+10), and when I work from home I go for a morning ride for 20km.
This is the main use of the cycle as of now now. 
 
My query is: should I think about changing to tires like Kenda Kwick Roller Sport Tire 26x1.75
 
My existing tire has ran only for 700+KM so far
I don’t have any issue with riding 10km one way with existing tires.
I have heard that 26x1.75 would be much faster, now I get an average of 18-20kmph, will it really improve if I move?
Do you have any suggestions for tires? Brand, model etc?
Is there any known issues if I move to slick tires, if I am not using it for hard trails? (other than the odd looks :-))
Another suggestion i got is to try Kenda small block tires which can be pumped up to 80PSi which will be similar to a slick on the road

Thank you,
Regards
Vishnu

[Opendro]

You will be marginally faster. But I think it is not worth it. If I were in your position, I would stick to the 2" tires. I had once tried the Kenda 1.75 on Trek 4300. The advantages are too small.

Anyway, hear out what others who have tried have to say.

[deepakvrao]

I 'think' that you will see a 2-3kmph increase in speed with slicks at higher pressure as compared to knobbies.

On Thursday, March 7, 2013 3:45:50 PM UTC+5:30, Vishnu Janardhanan S wrote:

[Yateesh Kumar]

+1 Opendro.

I did not find any significant difference when I rode with 1.3" slicks on my TREK 4300 except that I started noticing even small bumps, potholes, road irregularities, small stones appear like big boulders etc very similar to what the roadies experience.
Even on the speed of travel, guess there is not much to say that it is a big deal of difference
19km on 2.1 stock tyres in 42 min(office commute) vs 16.7km on 1.3 slicks in 32 min(ITT)
Though you may gain advantage in terms of roling friction, the distance covered per revolution of wheel is marginally lesser in case of slicks compared to stock tyres

On 7 Mar 2013 16:01, "Opendro" <ope...@gmail.com> wrote:

You will be marginally faster. But I think it is not worth it. If I were in your position, I would stick to the 2" tires. I had once tried the Kenda 1.75 on Trek 4300. The advantages are too small.

Anyway, hear out what others who have tried have to say.

On Thursday, March 7, 2013 3:45:50 PM UTC+5:30, Vishnu Janardhanan S wrote:
>
> Dear All,
>
>

> I ...

[deepakvrao]

Distance covered per revolution is meaningless. With lower resistance, the same power will generate a higher wheel rpm.

Like I said, 2-3kmph is pretty definite. Forget commute. Too many other factors. Just do a 1 hour ride at same effort on knobbies versus slicks and see the speed difference.

[Opendro]

I knew someone is going to catch that rpm thing :) Yateesh, doc is right. rpm difference is too small to make any significant difference in the rolling resistance (of bearing ball and polar moment of inertia). Hence for a given force/power, smaller wheel circumference will be compensated by higher rpm and thus give same speed.

I wouldn't say the difference is 2-3 kmph difference. Rolling resistance caused by the rubber contact is not the primary factor influencing the average speed of a bike. Major factor is the wind resistance, which is directly proportional to the square of the relative speed (of you vs wind) and the constant is the drag co-efficient which depends on the shape of the moving object (i.e. how aerodynamic the moving object is). I bet, a road bike geometry with MTB 2" knobbies will not be far behind.

However, there is a time when rubber contact resistance become significant - i.e. when one is riding on a tarmac (black tar) under the hot sun. Here, the contact resistance becomes annoyingly increased. On a regular morning and evening, it shouldn't matter that much. Just assume that MTB rubber contact resistance is even 5 times the slick tires, even then wind resistance will be a lot more times at speeds above 20. Imagine it like removing adding an extra passenger in Volvo bus to make it faster - not that comparable - but giving a theoretical picture :-P

BTW, disadvantages of slick as given by Yateesh matter too.

[deepakvrao]

I don't know Opendro. Most guys riding MTBs are at 18-20kmph, where air is less significant than at higher speeds.

I don't think there is any disadvantage to slicks on tarmac. In fact, knobbies have much higher risk on tarmac, as they are designed for dirt not smooth surfaces.

[deepakvrao]

Tghis calculator shows a 3.5kmph increase in speed at 150 watts, all else remaining equal.

[Opendro]

I didn't completely rule out a 2 kmph difference. I just wanted to avoid quoting it as I really doubt that much a difference. A difference between 18 and 20 is a lot significant (and doubful) than a difference between 38 and 40 for example.

I agree that on a "smooth" tarmac, slicks don't have any disadvantage. Else, you will feel even a slightest rough patch. Knobbies dont have risk on tarmac. For that matter, it is safer. Higher the contact point, the safer it is - wet or dry. Even in wet, knobbies are safer as it creates enough aquaplaning and flatter and wider contact points. But we are going too far with these points.

[Sandeep]

On Thu, Mar 7, 2013 at 5:21 PM, Opendro <ope...@gmail.com> wrote:

Higher the contact point, the safer it is - wet or dry.

 

True on tarmac.

Even in wet, knobbies are safer as it creates enough aquaplaning and flatter and wider contact points.

 

Exactly the opposite: knobbies have lesser contact with the road compared to a slick of the same width.

[deepakvrao]

Knobbies have LESS contact area than slicks, and hence the danger.

Aquaplaning at cycling tyre pressures is not even a factor.

Hence, slicks safer than knobbies. There is no doubt about this.

[Mayank Rungta]

Vishnu,

Like I mentioned some tires take a higher PSI and they are good for such commutes. Butcher had some nice ones on his Canondale. The advantage there is you may not need both set of tires. You could do most of the stuff with the same pair by adjusting the pressure in the tires. Of course trails like Turahalli downhill are not advised and the performance will not beat slick tires me thinks.

Generally it matters only if you do longer distances on weekends. I would consider such a shift if I were riding for the Brevets (in fact I just got a road bike instead of changing tires! :)).

Think through before investing. Probably try the bikes of those who have changed.

thx,
mynk

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[Opendro]

If knobbies have less contact area than slicks, knobbies should be fater, because the only detriment to speed for knobbies was the rolling resistance caused due to wider contact - either by virtue of wider tires or more deformation of the rubber.

[deepakvrao]

Increased resistance is NOT due to wider contact, but the presence and rolling of the 'knobs' themselves.

BTW, 18 to 20 is MORE significant as a percentage increase than 38 to 40. 

[Opendro]

Ok. Now, I have more people up against me so I thought I would google a bit : http://www.webmountainbike.com/selmtbtir.html :-D
Knobbies have poor traction on smooth surface but slicks are dangerous (let me add that we should assume similar rubber compound).

This just does not make sense. Please believe me. Otherwise, we would be having car tires designed bald and slick. They have the groves for aquaplaning on wet surface. On dry - bald or groves does not matter. It purely depends on the contact area. Why it matters on wet is because the wider surface of bald will not translate to wider contact area with road as the film of water will act like grease as it cannot seep out.

Of course, MTB knobbies are for aquaplaning. They are for digging into the dirt and get traction. I just threw in the aquaplaning just to cover on both wet and dry surface.

[Opendro]

Knobs will create resistance when it creates a contact that is almost of a self stable (like four knobs making a four legged stand). How much spaced knobbies we are talking here? All tires (except those road bike high psi ones) have enough contact far bigger than the spaces between the knobs to make any significant impact.

I will still stand by my claim (in the absence of any scientific measurement presented to us) that wider tires have higher rubber contact resistance because of wider contact. Otherwise, MTB tires should be rolling faster than slicks.

[Opendro]

Let me be clear that in spite of all these debates, I agree that slicks have marginal advantage in speed over fat tires. And I'm not particularly refuting this 2-3 kmph increase. Someone who have both tires can fill 50 to 70 psi (depending on tire spec) and go all out on two different days (spaced by a week) choosing same time in the morning. That will give a clear picture. Even comparing the top speed should be good enough (i.e. equal/max power applied from the same rider/bike and compare the speed) or if one has any device to measure the power/torque from the leg to the pedal (I don't know what kind of devices) and compare the speed vs torque graph.

[Opendro]

Sorry, I missed the "same width" in the line while reading fast. If it is of the same width, what is there for us to debate? ;-)

On Thursday, March 7, 2013 5:26:37 PM UTC+5:30, Sandeep wrote:

[Yateesh Kumar]

Butcher has the "dirt jump" tyres :D

More details contact Nelly/ Iggy

On 7 Mar 2013 17:30, "Mayank Rungta" <mr....@gmail.com> wrote:

Vishnu,

Like I mentioned some tires take a higher PSI and they are good for such commutes. Butcher had some nice ones on his Canondale. The advantage there is you may not need both set of tires. You could do most of the stuff with the same pair by adjusting the pressure in the tires. Of course trails like Turahalli downhill are not advised and the performance will not beat slick tires me thinks.

Generally it matters only if you do longer distances on weekends. I would consider such a shift if I were riding for the Brevets (in fact I just got a road bike instead of changing tires! :)).

Think through before investing. Probably try the bikes of those who have changed.

thx,
mynk

On Thursday 07 March 2013 05:21 PM, Opendro wrote:

>
> I didn't completely rule out a 2 kmph difference. I just wanted to avoid quoting it as I really ...

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[Sandeep]

On Thu, Mar 7, 2013 at 5:39 PM, Opendro <ope...@gmail.com> wrote:

This just does not make sense. Please believe me. Otherwise, we would be having car tires designed bald and slick. They have the groves for aquaplaning on wet surface.

See http://sheldonbrown.com/brandt/slicks.html

[Opendro]

For the benefit of others, I'm going to summarize what the website says:
 1. Smooth tires have better traction on dry - I agree, because more contact area. But site is talking about same size tires with smooth tread pattern, not leaner tire, which we generally associate with slick tires.
 2. On wet surface, slipperiness of slick tires is still a hurdle. I agree.
 3. Smooth treads have less rolling resistance, because it does not deform into tread voids. I wouldn't agree unless we are talking about really big and widely spaced knobs. I agree with really big and widely spaced knobs.

But whoever is reading, please don't make any mistake of assuming that those thin and slick tires have better grip/contact. That is all I can say before I leave the thread to the rest of the interested people :)

[Sandeep]

On Thu, Mar 7, 2013 at 6:20 PM, Opendro <ope...@gmail.com> wrote:

For the benefit of others, I'm going to summarize what the website says:

Others, read the link yourself and come to your own conclusions.

 

 1. Smooth tires have better traction on dry - I agree, because more contact area. But site is talking about same size tires with smooth tread pattern, not leaner tire, which we generally associate with slick tires.
 2. On wet surface, slipperiness of slick tires is still a hurdle. I agree.

I think he is talking about convincing people to use slicks as the next hurdle!

[deepakvrao]

Nope. Wrong.

Car tyres run wider and lower pressure, AND THAT'S why they need grooves for water to escape to prevent aquaplaning. 

Aquaplaning is NEVER an issue with bicycle tyres.

In fact F1 tyres for dry weather are slicks because slicks have maximum road contact and maximum traction.

I have ridden both on roads, and another issue is of knobs actually bending when you take turns, with the wheel slipping, or tending to slip out from under you. Known issue.

That link is wrong about slicks being worse on wet. Even on wet tarmac, slicks are safer than knobbies.

[deepakvrao]

Yes Sandeep, that is a very good link.

[deepakvrao]

Cut a long story short, change to slicks and you will enjoy your riding much more, IF it is road cycling that you are doing. Try it and give feedback. I'm sure you will be happy.

On Thursday, March 7, 2013 3:45:50 PM UTC+5:30, Vishnu Janardhanan S wrote:

[Vishnu Janardhanan S]

@Doc: I was not planning to go for road tires, i was thinking about  26x1.75 kind, will that be worth it?

I will probably wait for some time, let my existing tire wear out a bit. By the way how much mileage can i expect from my stock tires?

One of my colleague has a trek 4300 with Kenda Kwick Roller Sport Tire 26x1.75 i will try that for some 20km.

Regarding Butcher's tire, they are pretty expensive (for me) so will do some more research.

Would love to try it once, Anyone near whitefield who is using that tire?

Any suggestions on which tire to buy? say in 26x1.5-1.75 category, which can be used comfortably on roads.

Thank you,

Regards

Vishnu

[deepakvrao]

Absolutely worth the change. I also use 26X1.5 and 20X1.5.

I would suggest 1.5 instead of 1.75. Don't worry about traction.

[Vishnu Janardhanan S]

Any suggestions on brand and model?

[deepakvrao]

Depends on budget and where you planning to get them from.

Vittoria Rando Pro is what I have on one bike, and I think they are great. Can't remember what I paid though.

[Sanath Kumar S D]

http://store.bumsonthesaddle.com/products/kenda-kwick-roller-sport-tire

http://www.amazon.com/Kenda-Roller-Commuter-Bicycle-Folding/dp/B0026LJXBS

I saw couple of tyres in Track and Trial also . . .

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Regards,

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+ 91 988 019 4896

[Ravindra BR]

I'm using btwin 26x1.25 bought from Decathlon from past one year plus

[Vishnu Janardhanan S]

Hi,

Any reviews on the following, in terms of quality, puncture resistance, durability etc?

http://www.decathlon.in/TYRES-26x175-RECREATION-RIGID-BEAD

or

http://www.decathlon.in/TYRES-26x17-SPORT-RIGID-BEAD

The first one says TPI is 22, i just know that TPI means threads per inch and probably more the better?

is 22 TPI an indication of good/bad quality?

Thank you,

Regards

Vishnu

[Ravindra BR]

forgot to write

couple of 1000 km

2 punctures overall

my avg speeds 15 during brevet little less on other rides

Ravi

[Opendro]

Ignoring other points as we have covered enough. Commenting on this one with an example that everyone can experience on their own.

Regarding slicks on bikes on the wet surface, whatever I had said was theoretical and I don't have real experience or experiment I can write about. But on the car, if you have ABS and if your tires are bald, you can experience what a slight braking means on a wet tarmac. The judders of the ABS kicks in for even the slightest braking and that is accurately done by the ABS sensor whenever the tires lose contact. That is the best experience we can have for the moment.

[Opendro]

I agree. Slicks (i.e. smooth/clean tread pattern) will make the ride more comfortable. Just make sure you are not going for a small profile (which was the basis of my earlier arguments). Choose 1.95" or 2". I have tried the 1.75" Kenda slicks and I didn't like the experience.

[deepakvrao]

Thats the issue, car tyres are NOT comparable to bicycle tyres both with width as well as inflation pressure.

I think another read of God's website might be worth it :-)

[Opendro]

Physical laws are same. Only difference is that car wheel don't have to tilt in a turn as a bike wheels do. So, the shapes are designed accordingly and you will see tread patterns around bike tires, whereas car tires will have have only on the radially outer surface.

God's website - sure, I'll be the first to visit it if there is a "god" :-D

[Sreepathi Pai]

On Fri, Mar 8, 2013 at 2:21 PM, Opendro <ope...@gmail.com> wrote:
> Physical laws are same.

Dude, seriously? The physical laws that apply at light speed are very
different from those that apply at non-light speeds. And that's just
one exception.

Extrapolation is a nice technique, but it has its limits. I mean, are
you one of those guys who believes that because airplane blackboxes
are nearly indestructible, whole airplanes should be made of the same
stuff?

If you think bicycle design and car design are one and the same
because "physical laws are the same", well, wow.

> God's website - sure, I'll be the first to visit it if there is a "god" :-D

God in cycling circles is Sheldon Brown, and in particular, do read
Jobst Brandt's articles who is actually a proper mech engineer, and
has worked both with cars (Porsche) and cycles, and is German to boot.

http://sheldonbrown.com/brandt/

http://sheldonbrown.com/brandt/rolling-resistance.html

--
Sreepathi Pai

[deepakvrao]

Yes, physical laws are the same.

The same laws says that at the width and pressure of bicycle tyres, you need to be doing about 100kmph for aquaplaning.

Cars can hydroplane because:	Bicycles canNOT hydroplane because:
A car tyre has a square road contact, and the leading edge of the contact is a straight line. This makes it easier for a car tyre to trap water as it rolls.	A bicycle tyre has a curved road contact. Since a bicycle leans in corners, it needs a tyre with a rounded contact area, which tends to push the water away to either side.
A car tyre is quite wide, so water from the middle of the contact patch can have trouble escaping as the tyre rolls over it, if there are not grooves to let it escape.	A bicycle tyre is narrower, so not as much water is in contact with the leading edge at once.
Car tyres run at much lower pressure than bicycle tires.	The high pressure of bicycle tyres is more efficient at squeezing the water out from under.
Cars go much faster than bicycles, again leaving less time for water to escape.	At high speeds, hydroplaning is just possible for car tyres, but is absolutely impossible for bicycle tyres.

Even with automobiles, actual hydroplaning is very rare. It is a much more real problem for aircraft landing on wet runways. The aviation industry has studied this problem very carefully, and has come up with a general guideline as to when hydroplaning is a risk. The formula used in the aviation industry is:

Speed (in knots) = 9 X the square root of the tyre pressure (in psi.)

Here's a table calculated from this formula:

Tyre Pressure		Hydroplane Speed Miles per hour	Hydroplane Speed Kilometers per hour
P.S.I.	Bars
120	8.3	113	183
100	6.9	104	167
80	5.5	93	149
60	4.1	80	129
40	2.8	66	105

[O p e n d r o]

I think you didn't get the context. I said, just because car has four wheels does not make the grip and resistance different from bikes. Either it is car or bike, wider tires will run on lower pressure - because contact are (square inch) is more and total pressure should be able to hold the load. That is what I meant.

Thanks for enlightening me on the god. I seriously didn't know about it, specially me being an atheist, world is a much more complex and beautiful than an imaginary god could have handled/created.

But I do refer sheldonbrown for many of the things. And don't assume that the website is always right. For instance, he thinks that he is more comfortable with left hand than right hand if he has to ride only with one hand on handle bar because he is a left handler. With due respect of the tons of good information he has built, that is absolute bull shit. Ask any left hander or right hander, if they would have to ride a cycle and at the same time push another cycle, which hands would do what.... answer does not depend on whether the person is left hander or right hander. Sorry, too much digressing. But this will drive home my point.

[deepakvrao]

I dunno. You said that slicks on a bike would lead to aquaplaning, and gave cars as examples. I explained why they cannot be compared.

[Opendro]

That has a bit of good information on the square and round contact area. Thanks for the info. Convincing.

But it is laughable to say that hydroplaning is rare in automobiles. Seriously. Which website has quoted this. As I mentioned, I had run a bald car tires on wet with ABS. I just was not able to do a decent speed (well, not even 80 in a moderate highway traffic) while I could do a lot higher the moment I changed the tires. If it is not hydroplaning, what else would explain this? Or are we going to argue that even bald tires can handle equally on wet?

[deepakvrao]

http://en.wikipedia.org/wiki/Racing_slick

many bicycle tires made for street use are slick. Aquaplaning does not present a problem for bicycles due to their narrower width, higher pressure, lower speed, and circular cross section (due to the need to lean the bicycle in turns), the bicycle tire can penetrate the water layer to contact the road much more easily; in practice, grooved bicycle tires do not outperform slick tires on wet roads. However, many low and medium performance bicycle tires have substantial tread depth, because the bicycles are designed with off-road excursions in mind, in dirt, gravel, or sand the tread provides significantly improved traction. In addition, high performance bicycle tires, although designed for road use only, often have a very fine tread pattern, which appears to provide no difference in performance versus a slick tire and is only there for marketing purposes and as a tire-wear indicator. This is clear not only from direct testing of tires, but also from the fact that the texture of the road is itself coarser than the supposed "tread" on these tires.

Tire tread aspect ratio

The longer and thinner the contact patch, the less likely a tire will aquaplane. tires that present the greatest risk are small in diameter and wide.

Another very good link is here

http://myweb.tiscali.co.uk/13q11/cycling/tyres.html

The reason for tread pattern on a tyre is to provide a channel along which water can be displaced. If there is a layer of water between the tyre and the tamac, then you can aquaplane and the wheel will slide out. Let's get this straight - Bicycles DON'T Aquaplane. Cars and Motorcycles have a large contact patch where the tyre touches the road, and their weight is distributed over this so there is a low pressure applied. Bicycles have a very small contact patch, so the pressure applied is much greater. This pressure alone is enough to displce the water, avoiding the need for a tread pattern. If you do have a tread pattern, then you have less contact rubber. Instead of thinking "tread" think "gaps". Get a slick tyre and you'll have more rubber in contact with the road. If you want more grip, don't think "tread", think "wider"

[Opendro]

Did I? If I said that, I must have typed as a mistake or you could pinpoint if you can pick the post. To be honest, I started these arguments with the sole assumption that we are referring to leaner tires as MTB slicks. Then Sandeep brought in the seldon brown thing and "same width" thing, which was when I realized that I was using the word "slicks" in the wrong context. Slicks means smooth tread in contrast with deep threads and knobs. That is when I agreed with you guys that slicks are more comfortable, rolls smooth, etc. Then we moved onto the grips and rolling resistance of treaded vs slicks. So, my later part of arguments are with the true meaning of slicks.

[Opendro]

Really good points doc. I'm now thinking if I should change my stand on this aquaplaning for bicycles :-)

However, I still don't advise people to change to leaner (deliberate avoidance of the slicks) tires for MTB. The benefits are not just worth. Anyway, it is not do or death situation. One can always give a try and decide for themselves.

[Sreepathi Pai]

On Fri, Mar 8, 2013 at 2:57 PM, Opendro <ope...@gmail.com> wrote:
>
> Or are we going to argue that even bald tires can handle equally on wet?

On a *bicycle*, as Sandeep pointed out earlier, yes.

From <http://sheldonbrown.com/brandt/slicks.html>:

"However, machines that measure traction show that smooth tires corner
better on both wet and dry pavement. In such tests, other things being
equal, smooth tires achieve greater lean angles while having lower
rolling resistance. "

Brandt does know a thing or two about cornering:

http://sheldonbrown.com/brandt/images/tiretest.jpg

--
Sreepathi Pai

[O p e n d r o]

I'm getting convinced that aquaplaning may not be applicable to bicycle tires. If aquaplaning does not apply to bike tires, then I will have to accept that bald tires handle better on all surfaces. One thing less to argue about :)

[Sreepathi Pai]

On Fri, Mar 8, 2013 at 3:35 PM, O p e n d r o <ope...@gmail.com> wrote:
> then I will have to
> accept that bald tires handle better on all surfaces.

You're not reading things properly :)

From that same link:

"Tread patterns have no effect on surfaces in which they leave no
impression ..."

Explanation:

"That is to say, if the road is harder than the tire, a tread pattern
does not improve traction. "

Conclusion:

In mud, knobbies/tread is better.

--
Sreepathi Pai

[O p e n d r o]

Sree, now you are rubbing against me. I meant "all surfaces" => "wet / dry" Remember, I'm agreeing this only with the assumption that tire size/shape remains same except for the tread pattern. I'm mentioning this again and again so that the person who sought the answers in the first place shouldn't be confused with the word "slicks" and in turn gain on speed/traction/grip/resistance/etc.

[Sreepathi Pai]

On Fri, Mar 8, 2013 at 3:41 PM, O p e n d r o <ope...@gmail.com> wrote:
> Sree, now you are rubbing against me. I meant "all surfaces" => "wet / dry"

Okay. It's a bit hard to know when you're speaking in a particular
context in email.

> Remember, I'm agreeing this only with the assumption that tire size/shape
> remains same except for the tread pattern. I'm mentioning this again and
> again so that the person who sought the answers in the first place shouldn't
> be confused with the word "slicks" and in turn gain on
> speed/traction/grip/resistance/etc.

In general, on road, slick (treadless) bicycle tires are:

* better for speed: 2--3km/h is not insignificant. It's saves over a
whole hour for a brevet rider on a 200km brevet.

* traction/grip (which are the same), slicks will have better traction
on both wet and dry. They will have lower traction in sand/mud/etc.

* resistance: rolling resistance on slicks is /usually/ lesser, which
is why they're better for speed.

--
Sreepathi Pai

[deepakvrao]

Sree,

Well put.

One point I would disagree with is on sand. Knobbies on sand on *tarmac* would be as bad as slicks. Knobbies need some depth to get a grip, so off road yes, but on tarmac, in all conditions they are a fail.

I wonder why so many people ride knobbies when they don't go off road at all.

[O p e n d r o]

If the stock MTB tires are not having knobs or treads are not significantly deep and his question was about reducing the size (say, 1.95 Bontrager to 1.75 Kenda), that gain in speed is going to be questionable, because the rolling resistance of a treadless 1.95 and 1.75 would be so small compared to other significant resistances such as wind resistance.

I thought, I would mention it as your summary on speed can be misunderstood.

[Sreepathi Pai]

On Fri, Mar 8, 2013 at 4:01 PM, O p e n d r o <ope...@gmail.com> wrote:

> rolling resistance of a treadless 1.95 and 1.75 would be so small compared

Okay, I think there is still a slight misunderstanding worth clearing here.

Although wider (treadless) tires are thought to have higher rolling
resistance, there is a reason why racing is now switching from 23mm to
25mm. See:

http://velonews.competitor.com/2012/05/news/giro-tech-rise-of-the-25c-tire_218011

In particular, taking the whole system -- tires, tubes and pressure
results -- leads to interesting conclusions:

http://www.bikequarterly.com/images/BQ64TireTest.pdf

See the section, "Wide Tires are Faster".

Jan Heine's blog has more posts on wider tires and on performance of
tires, see: <http://janheine.wordpress.com/2012/06/13/bicycle-quarterly-performance-of-tires/>

> to other significant resistances such as wind resistance.
> I thought, I would mention it as your summary on speed can be misunderstood.

True. At speeds above 32km/h, air resistance is significant. That is
why we have drop bars ;)

However, speed due to slicks is *complementary* and independent of air
resistance.

i.e. Speed(Air resistance with slicks) is higher than Speed(Same air
resistance without slicks)

After this discussion, should we expect the Cleated Warriors to now
switch to wide slicks for BBCh? ;)

--
Sreepathi Pai

[deepakvrao]

yes, agree with the 25 faster than 23. It's been coming in many reports for a while now.

I still think when you go really wide, like 1.5, 1.5 will be faster than 1.95.

From safety point of view - my wife now rides 26 X 1.1 [Schwalbe Durano] on her Surly, and rides thru all kinds of roads on it. No problem. She is new to cycling too, so bike handling is also not great. 

When she rides from home she takes this bike and never has a problem even thru the crappy roads of KRPuram etc.

[Sreepathi Pai]

On Fri, Mar 8, 2013 at 4:46 PM, deepakvrao <deepa...@gmail.com> wrote:

> I still think when you go really wide, like 1.5, 1.5 will be faster than
> 1.95.

On <http://janheine.wordpress.com/2012/06/13/bicycle-quarterly-performance-of-tires/>,
there's a comment that has the word "linear" in it (can't seem to link
to comments, the comment starts as "The trend from 20 to 23 to 25 mm
is so linear ...").

Going by that comment, the answer would depend on where the plateau is
located. My armchair guess is that 1.95" (49mm) may not be
significantly slower than 1.5" (38mm).

--
Sreepathi Pai

[deepakvrao]

To use your words, my statement that I think 1.5 will be faster than 2 is also an armchair guess. ;-)

However, whenever I see comments about safety and skidding with slim tyres, I wonder about Shalini riding 1.1s without an issue. Grossly over estimated  this skidding of slim tyres.

[O p e n d r o]

I cannot talk on behalf of the team, but you just send me a link that says 2" is 1 ms faster to a km than 23C, I will buy it as long as price is same :-P

[Shankar Shastry]

Aren't you the captain? Why can't you speak on behalf of the team? :P.

Wait, I'm not a troll (alone). I do have something to add - I'm not well versed with internet knowledge on tires and traction but I have ridden 1.5 semi slicks, 2.0 full slick in the middle (a la da lam's head) and treads on sides, 1.95 knobbies, 2.1 small block 8s, 23c slicks, 26c slicks, 28c and 32c semi slicks and 32c knobbies. On rainy day commutes, in terms of comfort and control 

On smooth tarmac : 26c>23c>2.0>32c>28c>1.5>1.95>2.1.

On sand : 2.1 > 1.5 > 1.95 > 28c>32c>2.0>26c>23c

On broken roads, singletrack and (very minimal) roots : 1.95>2.1> 1.5> 32c knobbies> 32c>28c>26c> everything else(2.0 wasn't taken out trail riding)

[Chidambaran Subramanian]

Shankar, whats the formula ? Looks like a complicated algorithm to me.

[Shankar Shastry]

Lol. Not formula man. See legend below 

">" means item on left feels better than item on right. Vasu will come up with some pun for this.. mostly harping on the word "item" ? I have a bad feeling about this thread going south now :P

[Opendro]

You can link to the comments by clicking on the date. The link to the comment that you mentioned is this : https://janheine.wordpress.com/2012/06/13/bicycle-quarterly-performance-of-tires/#comment-4555