MTB Tire Direction

[Wyatt Earp]

If the leading edge is tapered to eliminate noise' date=' then why don't they taper both sides ??????? [/quote']

 

Because only the leading edge strikes the substrate. It's like running - your heel strikes the ground and your toe pushes away.

 

 

Logically if it makes a noise on the TAR' date=' and we are not talking roadbike tires here, then obviously there has to be a different effect.

 

[/quote']

 

Perhaps you want to rephrase that sentence. I don't understand it.

 

Why would I need to rephrase myself when you do not understand the question, I don't understand half of your contradictions in the first place and I surely don't need you to rephrase or give me further explanations.

[markStockton]

 

Mmmmmm' date=' interesting......

 

What effect would tire pressure have on grip?

 

I run relatively high (higher end of the recommendations) due to my weight (pinch flats/snakebites) and to minimise hard surface/gravel/tar rolling resistance.

 

Am I barking up the wrong tree here? 

[/quote']

 

Yes and no, Schwalbe did a study that indicated that there was not a significant increase in rolling resistance when running at a lower tire pressure, the lower preasure gives you much more grip on loose surfaces and sand,  however if you are running tubes you need to keep the pressure slightly higher to avoid pinch flats.

 

I run my tires alot softer than I used and apart from a wobbly feeling at the back on tar or really hard surfaces, much preffer the results.

 

 

I doubt any study will come to that conclusion. As air pressure increases, rolling resistance decreases. Perhaps the escape valve on your sentence is the use of "significantly". I think the difference is significant. That's just the nature of the beast.

 

I agree that traction on irregular surfaces improves with a decrease in air pressure and here the cause is obvious - the tyre moulds itself over something irregular and making that lot slip will require lots more force.

 

I had a look at the Schwalbe study at the time and I don't like their testing method. It is virtually impossible to measure something like rolling resistance by repeatedly riding the same irregular path. You just cannot do that accurately enough.

 

The only accurate way to measure rolling resistance is on a smooth surface such as a steel drum. That'll give you a base to work from and any irregularities you throw at the tyre will just add on top of the base. But at least the base measurements for various pressures are accurate.

 

 

 

 

 

 

I'm not taking the bait. Lower tire pressure works for me, you do what ever works for you.

 

Kona Fan, I agree with you on needing more grip at the front. As you get more and more confident you do more and more braking with the front. Grip at the front is vital, for the back it should follow the front with as little resistance as possible.  

 

[Johan Bornman]

 

cut cut cut

 

Well the clever developers designed it that way.  As some one said' date=' if you put LarsenTT on backwards you will wear the leading edge down to look like it should be.  So way bother putting it on counter directional if you only going to wear the tyre out faster?

 

[/quote']

 

You are right. If the design is such that it is quieter in a given direction, then use it like that. However, the point was made at some stage that directionality affects traction. It doesn't.

 

However, many tyres are not noisier in one direction than the other. So it makes no difference at all.

 

 

 Secondly' date=' why more grip is needed on the front wheel?  Because you steer with the front wheel!  Obviiously you can slide the back wheel to change direction (but that would meen you would need less, not more lateral grip on the back wheel).  The front wheel needs the lateral grip because you change direction (via steering) with the front wheel.  If your weight is on the front wheel and you don't have grp there the front wheel faces the danger of washing out when you turn.

 

(Now I await at least one flaming and two scientfic studies refuting of what I see as common sense)

[/quote']

 

The point is that the grip (traction) is not determined by the tread pattern but bu the co-efficient of friction in which tread pattern plays no role.

 

More grip (traction) is required on the front wheel, for both cornering and braking. These forces are larger than our accelleratoin forces.

 

Cornering forces are far less than braking forces.  As I explained, the fact that the bike leans reduces the effective downforce and that limits lean-over traction and there's nothing you can do about it.

 

Don't forget, the original debate was (and I do summarise it) "does tread pattern influence traction?"

 

 

[Wyatt Earp]

Kona Fan' date=' I agree with you on needing more grip at the front. As you get more and more confident you do more and more braking with the front. Grip at the front is vital, for the back it should follow the front with as little resistance as possible.  
[/quote']

Isn't that what I suggested in my first post

I guess what we have seen here is that there are those that actually do take a corner aggressively and will always look for the maximum traction and then there are those who feel that road tire technology should apply to MTB's as well.

Oh sorry I forgot, there is no such thing as technology in tires

[markStockton]

 

Isn't that what I suggested in my first post

I guess what we have seen here is that there are those that actually do take a corner aggressively and will always look for the maximum traction and then there are those who feel that road tire technology should apply to MTB's as well.

Oh sorry I forgot' date=' there is no such thing as technology in tires

[/quote']

 

 

I'm not a "Vaporware Consultant", so I can only comment from experience.

 

I can certainly confirm that there is technology in MTB tyre design, just comparing my Hutchinson Pythons and Schwalbe Racing Ralphs can confirm that. Both have nice low rolling resistances, however the RR's have bucket loads more grip in the loose. Funny enough way different tread patterns as well.   

 

 

[nochain]

So if tread pattern has no influence on grip/traction when cornering how do you increase grip?Are you only refering to the Pattern of the tread and not the tread itself,more tread(bigger) more grip?

 

 

[dirtrider]

Johann can you start speaking english please !!!

 

 

[NotSoBigBen]

DR - ek probeer vir jou help my ou, die ou se dit maak nie saak hoe om jy die tyre opsit nie jy gaan nog steeds stadig wees ......

[Tumbleweed]

to be honest, i'm struggling to get a grip on this thread

[GoLefty!!]

  

Firstly' date=' the avatar is Brad, Headshok mascot. Lefty is a Headshok product.

Cannondale Headshok suspension is based around a square tube sliding in a round hole.

There are two product ranges; Fatty and Lefty. got it?

 

[/quote']

Thanks for the lesson, I did not know that, I have never seen the inside of one

For the Lefty they shove the SI designation under his chin, maybe I am just being anal, it won't be the first time.

It's actually a round tube with four sides that have been machined with a flat surface per side, each one of the four flat surfaces hosts a metal slider then a set of needle bearings with another metal slider sandwiching the needle bearings, these get held together by a retainer clip.

Pretty much the same way the Egyptians used to transport those massive blocks of stone by using logs.

Let's see how big a fan you are, I have a question.

Which well known road cyclist used to race for Cannondale and made it to his  first olympics as a mountainbiker in the first olympic MTB race ?

Secondly you must have a beeeeeeg scale

Thirdly, weight is a big factor in keeping things stable, ever tried to fly a radio control plane with the nose hanging down or one wing heavier than the other, yes it's balance and if the balance is not equal we have stability issues.

The word stability or stable can be found in any old dictionary nowadays

Your adhesion theory also does not apply, try again.

 

Si is a concept of which Lefty, Fatty, BB30, Hollowgram I& IISL, and Headshok Headtube all form part. It is nomenclature given to a family of technologies that makes a Cannondale unique. At least I know you have lifted the boot of the lefty to see whats underneath and therefore demystified it for yourself. Have you looked inside the DLR2, or FoX Inertia Lefty's yet? Have you tuned the Shim stacks in either or changed the negative springs to accomodate a rdiers weight on a size of bike that was not tuned to accomodate that weight?

 

Cadel Evans

 

No I use two bathroom scales. those german scales are pretty accurate. One under each wheel is sufficient.

 

Balance in a model aircraft has nothing to do with balance on a bicycle. Please use relevant examples.

MAss balance in an model aircraft is  exaggerated due to it's light weight and the big influence of the aerodynamics.

Balance discrepansies can be trim out by tweaking the wings, ailerons or by fitting trim tabs on the stabilators.

Stability is merely the ability to maintain balance. How does a tyres tread affect this?? please explain because as far as I can see the tyres tread is not pulling both my arms and my toes equally to keep me upright on the bike. Or is this one of those sinister third forces...?

 

On a bicycle the riders weight provide sufficient balance because it rests over the centre line of the bike while riding in a straight line. While cornering the weight is on the inside of the arc prescribed by the path the contact patch follows. The contact patch deforms because now the load is made up of vertical as well as side forces. The tread merely serves as an anchor to resist the side load therefore the deeper the tread can penetrate the more the side forces can be resisted. the friction forces remain the same. It makes stuff al difference what the shape of that tread is.

 

Also, it is impossible to corner a bike within weight on thefront wheel. Without weight, there is no grip. grip is what turns you. A body will remain in a state and direction of motion unless acted upon by a force. So contrary to popular belief you do need weight on the front wheel and the close it is too 50/50 the better the balance of the bike and the better it will turn. On a descent, a rider will move their weight slightly rearward to counter the weight transfer due to the gradient, to maintain the weight distribution.

 

Therefore, your front tyre is the most important tyre on your bike. It absorbs the braking energy & turning  forces. It's grip is a function purely of the friction properties of the rubber and to a much smaller extent, the depth of the tread blocks. the shape and direction of hose tread blocks means nothing in science but clearly is a gold mine to a marketer.

 

 

[NotSoBigBen]

DR - ek probeer vir jou help my ou' date=' die ou se dit maak nie saak hoe om jy die tyre opsit nie jy gaan nog steeds stadig wees ......[/quote']

 

HR why you struggling see above ........

[dirtrider]

Thanks BB now all became clear ! By the looks of this all I should just go with slicks .

[Tumbleweed]

DR - ek probeer vir jou help my ou' date=' die ou se dit maak nie saak hoe om jy die tyre opsit nie jy gaan nog steeds stadig wees ......[/quote']

 

HR why you struggling see above ........

 

wie bitte, ich ich verstehen nicht

[GoLefty!!]

Isn't that what I suggested in my first post

I guess what we have seen here is that there are those that actually do take a corner aggressively and will always look for the maximum traction and then there are those who feel that road tire technology should apply to MTB's as well.

Oh sorry I forgot' date=' there is no such thing as technology in tires

[/quote']



I'm not a "Vaporware Consultant", so I can only comment from experience.

I can certainly confirm that there is technology in MTB tyre design, just comparing my Hutchinson Pythons and Schwalbe Racing Ralphs can confirm that. Both have nice low rolling resistances, however the RR's have bucket loads more grip in the loose. Funny enough way different tread patterns as well.   

 

 

Funny enough the RR are also made of a much softer and therefore higher coefficient of friction rubber compared to the Pythons...

 

The technology in the tyres is in the volume and casing shape. The tread is what makes you say:" ah my donner dis nou a mooi rubber ne." and you by it based on this.

[NotSoBigBen]

DR - ek probeer vir jou help my ou' date=' die ou se dit maak nie saak hoe om jy die tyre opsit nie jy gaan nog steeds stadig wees ......[/quote']

 

HR why you struggling see above ........

 

wie bitte, ich ich verstehen nicht

 

Du alte flaume, bisst due deppert oder wass?

[NotSoBigBen]

Thanks BB now all became clear ! By the looks of this all I should just go with slicks .

 

Ja maar watter 'rigting' huh?