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General Category => General Discussion => Topic started by: sauldgold on November 14, 2018, 10:28:55 PM

Title: Tire direction
Post by: sauldgold on November 14, 2018, 10:28:55 PM
Hi all, I have a pair of SP snowflake mag wheels.   I'm about to mount a pair of Pirelli Sport Demon tires. 

As expected, the shop manual says to mount the rear tire so that sidewall arrow indicator points toward the riding direction.

HOWEVER, it then says to mount the front tire so that the arrow indicator points AGAINST the riding direction.

Is this a mistake?

Is it some archaic practice that no longer applies today?

Is this negated by the use of modern tires?

I would appreciate any guidance here.
Title: Re: Tire direction
Post by: guzzisteve on November 14, 2018, 10:59:09 PM
Put them both on w/arrow pointing direction of travel. There was a thread about this a few weeks ago, same Q about what it says in manual. There are front & rear tires now, better stuff.  Look back some pages here you'll find it.
Title: Re: Tire direction
Post by: wirespokes on November 14, 2018, 11:29:05 PM
Simple answer right here and now - it's like Steve says. It may have been in the old days front tires in our size weren't available so a rear had to suffice. Too bad that wasn't explained in the manual. It has to do with tire construction and the expected load on the tire. If it's a rear tire being used on the rear, point the arrow in the direction of rotation. If that rear tire is used in front (it can be done if necessary), where braking is the load not driving force, the tire needs to be reversed.

I'd definitely go with the tire markings if there was any question.
Title: Re: Tire direction
Post by: yogidozer on November 14, 2018, 11:32:58 PM
Point them in the direction you want to go, you already know where you've been.  :wink:
Title: Re: Tire direction
Post by: earemike on November 15, 2018, 03:06:24 AM
Yeah, if you need to fit a rear to a front or vice versa put the arrow facing the wrong way.

I’m sure there are threads here about Tyre construction, there are more braking stresses on the front, acceleration stress on the rear.

Recently saw some universal fit tyres online - mounting changes depending on front or back.

Enjoy, my pirellis have been good
Title: Re: Tire direction
Post by: greer on November 15, 2018, 04:01:18 AM
Here's a copy&paste from Avon's website:


Can I fit a front tyre on the rear and a rear on the front?

Avon would not normally recommend this fitment. If you do this however, due to the way tyres are manufactured, you should reverse the tyre’s direction of rotation if you fit a front tyre on the rear or a rear tyre on the front of your bike. During tyre manufacture, a length of tread rubber is wrapped around the carcass and joined together with an angled bevel type joint. This joint is orientated so that as the tyre rotates, this joint stays shut. As the rear tyre provides drive and the front tyre provides braking, the joint is made one way for the rear tyre and the opposite way for the front. Fitting incorrect tyres could cause potential MOT/insurance issues and may affect the bikes handling capabilities.

Sarah
Title: Re: Tire direction
Post by: Groover on November 15, 2018, 07:33:22 AM
I don't recall the arrow direction on mine, but go with the direction shown here and all will be great. You can also run those tires tubeless on those rims with the right valve installed - of course, consider doing that at your own risk.


(https://thumb.ibb.co/f3eFvL/Groover-s-G5.jpg) (https://ibb.co/f3eFvL)
Title: Re: Tire direction
Post by: Texas Turnip on November 15, 2018, 07:46:22 AM
Who else remembers using the 400-18 Goodyear all-traction tires that did not have arrows for direction of travel or say front or back? Didn't even have date of mfg.
All of us Guzzi riders were running them in the 70s. The front would start to road hop, then we put it on the rear. Rough ride until it smoothed out. Somehow, we survived.

Tex
Title: Re: Tire direction
Post by: twowheeladdict on November 15, 2018, 08:45:53 AM
Simple answer right here and now - it's like Steve says. It may have been in the old days front tires in our size weren't available so a rear had to suffice. Too bad that wasn't explained in the manual. It has to do with tire construction and the expected load on the tire. If it's a rear tire being used on the rear, point the arrow in the direction of rotation. If that rear tire is used in front (it can be done if necessary), where braking is the load not driving force, the tire needs to be reversed.

I'd definitely go with the tire markings if there was any question.

I believe it also has to do with the rain groove in the tire and cornering grip.
Title: Re: Tire direction
Post by: hannibal smith on November 15, 2018, 12:07:57 PM
I was pumping gas and some fellow comes over to check out my bike.

After the usual "I had one of those", he proceeds to insist that my front tire is on backwards. I squat down and show him the indicator arrow on the sidewall (much to my relief, it was correct, even though I knew it, he stated it with such conviction, I began to wonder myself!).

Anyway, he walked away still insisting it was backwards. I just rode off thinking that was an odd encounter.
Title: Re: Tire direction
Post by: wirespokes on November 15, 2018, 12:50:31 PM
"...he proceeds to insist that my front tire is on backwards."

Was the tire positioned so the arrow was on the bottom? If so, it would have pointed backwards.  :grin:
Title: Re: Tire direction
Post by: hannibal smith on November 15, 2018, 02:22:01 PM
"...he proceeds to insist that my front tire is on backwards."

Was the tire positioned so the arrow was on the bottom? If so, it would have pointed backwards.  :grin:

Haha! Good point!

Title: Re: Tire direction
Post by: sauldgold on November 15, 2018, 02:49:45 PM
Thanks for the help everybody
Title: Re: Tire direction
Post by: oldbike54 on November 15, 2018, 03:06:38 PM
Point them in the direction you want to go, you already know where you've been.  :wink:

 Does that apply South of the equator ?

 Dusty