Chevrons forward or backwards: Pause for thought.

Discuss light weight issues concerning road bikes & parts.
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theremery
Posts: 2673
Joined: Sun Jun 12, 2005 10:56 am
Location: New Zealand

by theremery

[Note...none of this applies to tyres like GP4000s etc...just follow the manufacturers "direction of rotation"]
Years ago (30 years) we just glued our tubbies on label to the drive side. I never thought much about it and just did as the others did. After reading a question on the actual wheel weights thread, I checked something and was somewhat disturbed by what I saw. I'd generally have the "chevrons" on mixed tread type tyres facing "arrow forward" when viewed from above but a question posed had me check a semi-modern Vittoria tubbie re it's label and chevron direction and it is definitely "chevron facing to the rear" of the bike when viewed from above if the label is glued on the drive side. Why does this disturb me?
If you view the tyre from underneath, the way I have always done my veloflex masters is like option 1 (chevrons forward viewed from above) BUT this leads to the line of the chevron being parallel to the direction of (potential) slip when in contact to the ground. I've just layed under my bike and checked this out.
That seems counter-intuitive. Surely having the line of tread at 90 degrees to the potential direction of slip would be the go??!! (like the vittoria tubbie)
Are the chevrons all about water removal? (perhaps this explains it) or have I been following a stupid and ill-informed methodology for all these years? Does it vary from tyre to tyre? Does anyone have an old Clement Road #3 or #1 they can check for me (seta, seta extra/ yellow, green label)? Have I just plain "got it wrong"?
The tyres I'm most interested in here is veloflex mixed tread type tyres (masters, corsas etc) as, paired with a decent latex tube, these are by far the best tyres for local conditions for general riding (they are a P.I.T A. for lack of puncture protection but cheap enough that I don't cry when I destroy one). These have labels on both sides BTW so aesthetics etc with "label on the drive side" just doesn't matter. They are not marked with a rotation direction but even if it is a tiny difference....is one way better than the other?
Pausing for thought.
-Geoff/theremery.
Updated: Racing again! Thought this was unlikely! Eventually, I may even have a decent race!
Edit: 2015: darn near won the best South Island series (got second in age
-group)..woo hoo Racy Theremery is back!!

Barrie
Posts: 26
Joined: Fri Mar 23, 2012 8:56 am
Location: lancashire UK

by Barrie

Just talking about the chevrons they must face forward to clear water to the side of the tyre

Barrie

by Weenie


Mackers
Posts: 472
Joined: Wed Sep 05, 2007 2:02 pm

by Mackers

Got something for sale Barrie?

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Cyco
Posts: 1903
Joined: Sat Nov 30, 2002 4:49 am

by Cyco

According to a tyre designer I from Michelin I got to speak to any chevron, or other tread patten is there to make you feel good.

They add no ability to clear water nor are they correct size to match road road 'roughness' to increase grip. They are too small and soft to do anything but get squished out of existence most of the time.
Success is how far you you bounce back up after being knocked down

RWH
Posts: 47
Joined: Thu Sep 03, 2009 7:36 pm
Location: Turku, Finland

by RWH

I actually mailed this question to Veloflex, when I bought some of their Carbon tubulars earlier this year and their answer was as follows:

For the rotation direction you have to look at the outer lines of the thread, /\||||||/\ , the two lines projection (marked in red) at the extreme sides must form an imaginary arrow that points to the direction you ride.
Never give up, never say die.

krusty
Posts: 90
Joined: Thu Dec 08, 2005 12:48 am

by krusty

Just as with tractor tires or any other tire that has a prominent chevron pattern, the track you leave on the ground is the same as if you walk with your toes splayed outward. Easy to remember.

RichTheRoadie
Tinker, Taylor, Tart
Posts: 1985
Joined: Sat Nov 29, 2008 8:00 pm
Location: Sydney, Aus.

by RichTheRoadie

Cyco wrote:According to a tyre designer I from Michelin I got to speak to any chevron, or other tread patten is there to make you feel good.

They add no ability to clear water nor are they correct size to match road road 'roughness' to increase grip. They are too small and soft to do anything but get squished out of existence most of the time.

SO true.

The tread pattern on a bicycle tyre is nothing but a wear indicator. Take the Mavic tyres for example - awesome grip in the wet or the dry, ZERO tread.

Murphs
Posts: 1117
Joined: Thu Feb 05, 2009 12:04 am
Location: Gold Coast, QLD, Australia

by Murphs

The notion of tread lines on 23mm (or 21mm or 25mm or 27mm) bicycle tyres to disperse water is ridiculous.

Water dispersing tread patterns on car and motorcycle tyres are there to lessen the likelihood of aquaplaning.

Bicycle tyres are too narrow to aquaplane as there is no broad surface for the water to be trapped under.

If anything, tread patterns on bicycle tyres would decrease cornering grip due to the slightly reduced surface area of rubber in contact with the road surface, but this would be negligible at best.

krusty
Posts: 90
Joined: Thu Dec 08, 2005 12:48 am

by krusty

Yeah, just put them the right way around. It's so easy compared with arguing with everyone who notices...

fdegrove
Tubbie Guru
Posts: 5851
Joined: Tue May 03, 2005 2:20 am
Location: Belgium

by fdegrove

Hi,

The tread pattern on a bicycle tyre is nothing but a wear indicator. Take the Mavic tyres for example - awesome grip in the wet or the dry, ZERO tread.


Any tread pattern, regardless of shape or orientation, will invariably increase rolling resistance.
It also does absolutely nothing to increase grip. If it would then rolling resistance would decrease. it does not.

The entire (and utterly stupid) idea just stems from the car tyre industry where of course tread patterns do serve a purpose.

Regarding the assumed correct direction of the chevrons, traditionally (and that's all it is, a convention) they have the arrow point forward.

Just thought I'd add my 2 cents. :P

Ciao, ;)
Being a snob is an expensive hobby.

notsoswift
Posts: 176
Joined: Mon Mar 07, 2011 10:00 am
Location: Melbourne

by notsoswift

Ignore everything else - Label to the drive side, nuff said

fdegrove
Tubbie Guru
Posts: 5851
Joined: Tue May 03, 2005 2:20 am
Location: Belgium

by fdegrove

Hi,

Some carry labels on both sides nowadays..... :mrgreen:

Ciao, ;)
Being a snob is an expensive hobby.

by Weenie


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ergott
Posts: 2719
Joined: Tue Apr 18, 2006 3:03 am
Location: Islip, NY
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by ergott

fdegrove wrote:The entire (and utterly stupid) idea just stems from the car tyre industry where of course tread patterns do serve a purpose.

Ciao, ;)


Funny enough, even in the auto industry tread aesthetics are considered. They have to look like they work.

This is the only tread that I believe prioritizes function over anything else.

Image

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