Tires Armadillo tire - just noticed something...

M

Mary

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I am making a rack to hang a travel bag on the back of my bike. I just noticed the following on the sidewall of the tire: "Rotation" with an arrow.

Has anyone else noticed this? I assume it is like a radial tires on cars. The tire is meant to rotate in one direction only.

Comments?
 
It has to do with thread design and water dispersion it has to rotate a certain way or your not getting maximum performance. Now as long as staying inflated I wouldn't think it would make much of a difference.
But I do remember a tire I had with a rather thin side wall something like if you install it the wrong way the side wall can actually tear up but don't quote me.
 
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With bike tires, you don't need to worry about water dispersion at all. At 40-50 psi, you would need to be hitting 80 MPH + before you could hydroplane on a slick.
 
Most tyres don't have the rotational arrow meaning to me u can put them any way u want,but the ones that do it's better to follow the directions.
If i installed a tyre with the rotational arrow incorrect i'de force myself to take it off & start again :rolleyes:.....thereafter check FIRST.
 
Most tyres don't have the rotational arrow meaning to me u can put them any way u want,but the ones that do it's better to follow the directions.
If i installed a tyre with the rotational arrow incorrect i'de force myself to take it off & start again :rolleyes:.....thereafter check FIRST.

I agree with you. A local bike shop installed the tire for me and I didn't notice the directional arrow until much later. On Monday, I called Specialized and spoke to the tech dept. and the guy told me the same thing. He said it was important for traction. I figured with a motor assisted bike, I had better bite the bullet and take the tire off along with the motor and do it right. :cry:

Forgot to mention: the directional arrow is pointed the wrong way.
 
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wow you actually talked to someone in a tech dept that actually knows the right answer for a change.

Since most of us are running some sort of mtb tire the good tires will have a directional arrow, it is also not unusual to find a good set with completely different threads,one designed for the back and one for the front, so yes it has to do with traction mostly coming into its own in off road preformance.
 
You picked a great all around tire Mary. I have a pair of Armadillos with Specialized thornproof tubes on one of my bike and have taken it on some rough terrain. The real test was when I took it on a 60+ mile dirt trail in the Mojave Dessert with 100+ degree weather. By the time I got back on the road, both tires were completely covered with thorns (at least 1000 thorns) I pulled everyone of them out and to this day the tires still hold air.
BTW, the way you can tell if you have the tires on correctly is you stand behind the bike, The Vs will point upwards. My gut feeling is if they have directional tire arrows, there has to be a good reason why the manufactor wants us to install them that way.
 
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There may be a reason to have the direction of the tread specified, but, you can be positive, with a bicycle tire, that it's not for water dispersion.

Because auto tires have tread - in fact, NEED tread, so as to help with hydroplaning, bicycle tire makers seem to feel the need to include tread on their tires, too, as a comfort factor for buyers. There's no reason for tread on road tires, but, the marketing blurbs will say they're there to 'channel water.'

At 50 psi inflation pressure, a smooth, treadless tire can't hydroplane 'till you hit nearly 70 MPH!

The actual formula to calculate the potential speed that a hydroplane condition could exist is:

Speed (in MPH) = 9.72 X the square root of the tire pressure (in psi.)

The higher the air pressure in the tire, the higher the minimum potential hydroplane speed. Note that the only variable involved in this calculation is the air pressure...

If you wanted to rearrange the formula to see what the minimum tire pressure would need to be, if your maximum speed was, let's say, 35mph, it works out to 13 psi.
 
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Learned sumpthin' yesterday.

A customer brought his wife's bike over, (odd thing happened, the punctureproof tube had failed at the valve, "popped off"), when he put the wheel on, he goofed up the axle washer setting I had, and the brakes (and the axle angle...)

Anyway, when he went to Wal-Mart to get the slime punctureproof tube, he asked the guy how much pressure they put in tires.

The guy told Glenn that the WallyWorld compressors are set at "42 psi", and "manufacturer specs" don't matter (lawn mowers or bikes or back in the auto repair shop) 42 is what you get.

Me? I always stay under specification, and never exceed 35 on the cheap tires that specify "40". (They fail at the bead when they hit a pothole if they have too much air).
 
I got a set of armadillo crossroads for my b-day :)
(front from azvinnie & my daughter, rear from the girls :cool:))
the sidewall says between 35-80psi
at 40, they seemed a little soft
bumped up to 50, and they feel much better
what psi are other riders using ???
 
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