Tire direction of rotation

[Bluenoser]

I ride a 99 R1100RT.  The front tire is nearly worn out, its worn on the left side, the centre and the right side are barely worn at all.  Normal wear for an RT I know.  I'm sure I'm not the first person to wonder what hazards I would be introducing by reversing the direction of rotation.  Is water evacuation by design of the tread the only consideration or are there others?

[Rinkydink]

Someone a lot smarter than me will chime in soon but I say absolutely not. Seems I read once a radial belt rolls one way you don’t change it or something like that. Tires aren’t cheap but piece of mind is a wonderful thing at 80 mph. 

[Skywagon]

ill start with I don't know....When radial car tires came out as Rinkydink pointed out they were only supposed to be run in one direction.  The story was if you reversed them it could cause the belts to separate.  I don't know if true or not.  If you want to know for sure, send the tire mfg. a quick note and ask.

[Michaelr11]

1 hour ago, Bluenoser said:

I ride a 99 R1100RT.  The front tire is nearly worn out, its worn on the left side, the centre and the right side are barely worn at all.  Normal wear for an RT I know.  I'm sure I'm not the first person to wonder what hazards I would be introducing by reversing the direction of rotation.  Is water evacuation by design of the tread the only consideration or are there others?

 

The front tire design is meant to optimize braking capability and the sipe design is intended to channel water away from the contact patch.  Turning the tire around would get you braking and water dispersion that are below what the tire was designed to provide.  You would also have a worn tire on one side.  Would you be planning to only make left turns?  I can't even imagine what might happen if you had an accident and the insurance found the tire turned around.

 

How many miles have you put on this tire?  Just buy a new one.

[elkroeger]

I'm sure there are people all over the world with their tires mounted "backwards" with no ill effects.  If there was a real problem with that, such as impending doom, then there would be some mechanism to absolutely prevent improper rotation.  We all rotate the tires on our cars.  Shoot, it's even recommended!  Many car tires also have arrows these days.

 

Personally, I wouldn't think twice about mounting it with the arrow going the "other" way.  And I don't think the tread (such as it is on modern street tires) does much of anything.  I think we could all just ride on racing slicks and nobody would ever notice the difference.  ymmv

[roadscholar]

8 hours ago, elkroeger said:

 

And I don't think the tread (such as it is on modern street tires) does much of anything.  I think we could all just ride on racing slicks and nobody would ever notice the difference.  ymmv

 

I hope that’s a joke but just in case. We could ride around on racing slicks except for two things, one they’re made of soft rubber and wouldn’t last very long, like under 1000 miles of normal use. And two when it rains it’s like being on black ice as in zero traction. So your mileage could vary some, it could be not much or not at all : )

 

To the OP, if you don’t want to spring for a new one go to your local mcy shop and find a good takeoff, lot of people change them as a set and a front could still have 75% left, 17 is a common size too.

[Rougarou]

12 hours ago, Skywagon said:

ill start with I don't know....When radial car tires came out as Rinkydink pointed out they were only supposed to be run in one direction.  The story was if you reversed them it could cause the belts to separate.  I don't know if true or not.  If you want to know for sure, send the tire mfg. a quick note and ask.

 

I dunno, that may be historically the way it was stated for autos, but many tire shops will ask "white letters in or out?", thus reversing the arrows printed on the tires if you want the "white letters in".  

 

 

[Bluenoser]

1 hour ago, Rougarou said:

 

I dunno, that may be historically the way it was stated for autos, but many tire shops will ask "white letters in or out?", thus reversing the arrows printed on the tires if you want the "white letters in".  

 

 

 

What got me thinking about this is that automobile tires are rotated regularily for even tread wear, including reverse direction unless they are tread designed for one direction only.  I've read of people riding thousands of km while unaware that their tire was mounted in reverse in error, with no ill effect.  Probably happens fairly often.  

My riding right now is 300-400 km day trips always planned for dry weather days, rain could happen of course.  I by no means wait until the tires are showing canvas before replacing but once they're say 80% worn there is very little capability remaining to expel water regardless of rotation direction.

[TSConver]

There will be no "ill" effect on the tire if it is mounted backwards.  As mentioned most motorcycle tires are directional to maximize traction for the wheel it is on. Rear tires for maximum acceleration and front tires for maximum braking.  That is my the tread direction often looks different from the front to the back.

[elkroeger]

On 6/1/2021 at 10:50 PM, roadscholar said:

I hope that’s a joke...

 

Actually, I guess I misspoke.  Of course racing tire compound is too soft, and would wear out way too fast.  I thought that would be obvious.  But as far as the tread itself goes:  No, I don't think most anyone would notice if they were riding slicks (made with road tire compound).  Look at the tread design on road tires.  There is no rhyme or reason to the wild flourishes between brands or models.  They look cool, I guess, but the lack of consistency tells me that they don't really do anything. 

 

For example, look at snow tires for your car.  Years ago, they all looked alike - bigger knobbies, deeper channels, softer compound.  Today the vast majority of snow tires have more sipes than deep tread.  Some of them are virtually treadless, except for the sipes.  Now there's a trend.  It tells me that, for most drivers, the sipes are what makes a snow tire work.  There's no trend to road bike tire tread.  It's just marketing, and I suspect they have art majors cooking up tread design, rather than mechanical engineers.

 

Look at bicycle tires.  Back in the 80s, there was a revolution.  They did away with the tread completely.  There was a lot of skepticism.  People believed they needed tread on their bicycles.   Today, slicks are everywhere.  It's also commonplace to mount road slicks on mountain bikes, for street riding.   I've actually done a lot of dirt riding on my street slicks, and while it is noticeable, the difference is nowhere near as great as one might think.  Tire pressure has a greater effect.

 

Anyway, that's just my opinion, and opinions are like armpits:  Everyone has one or two, and they usually stink.

[lather]

I don't recommend it but I did it once and survived the 6 or 7 thousand mile life of the tire. BUT, it was a Shinko 700 dual sport tire on a KLX250S. Probably pretty different from whatever you have on your RT

[Oldrider51]

I look at it this way, if the rotation direction did not make a difference in the tire performance whether wet or dry, then the manufacturer would not place a direction arrow on the tire. Always mount the tire with the direction arrow looking forward.

[roadscholar]

7 hours ago, elkroeger said:

 

 But as far as the tread itself goes:  No, I don't think most anyone would notice if they were riding slicks (made with road tire compound). 

 

Evidently missed the more important point, you absolutely have to have tread on your tires when it rains, it's what channels the water away from the contact patch that keeps you from hydroplaning. It's the only reason street tires have tread but it's a really important one. 

 

7 hours ago, elkroeger said:

 

There's no trend to road bike tire tread.  It's just marketing, and I suspect they have art majors cooking up tread design, rather than mechanical engineers.

 

Tell that to the folks (and engineers) at Michelin that have spent a lot of time and money proving otherwise.

 

https://michelinpg.com/

 

https://michelinmedia.com/motorcycle/&Page=1

[axabmw]

Many years ago I had a new rear tyre put on a Honda 125. I left the tyre place and within a few miles I noticed the tyre was spinning slightly when I pulled away and locking up when I braked.

I pulled over and checked the installation and it had been fitted back to front. I went back to the tyre place and he said he was just closing, I'd have to come back the next day..

I parked the bike under the line of his shutter and started to remove the wheel (I'd done it so many times in it's 65,000 miles it only took a few minutes). By the time he'd said he wouldn't have time to remove the wheel, I'd handed it to him.

I wasn't leaving till it was done.

[Rinkydink]

The OP was about running it one direction then changing it, NOT installing it in the wrong direction initially. 

[dirtrider]

1 hour ago, axabmw said:

Many years ago I had a new rear tyre put on a Honda 125. I left the tyre place and within a few miles I noticed the tyre was spinning slightly when I pulled away and locking up when I braked.

I pulled over and checked the installation and it had been fitted back to front. I went back to the tyre place and he said he was just closing, I'd have to come back the next day..

I parked the bike under the line of his shutter and started to remove the wheel (I'd done it so many times in it's 65,000 miles it only took a few minutes). By the time he'd said he wouldn't have time to remove the wheel, I'd handed it to him.

I wasn't leaving till it was done.

Evening   axabmw

 

That had nothing to do with mounting direction, a lot of newly mounted motorcycle tires act that way until scrubbed in due to either tire  release compound left on the tire from the manufacturing process and /or tire mounting lube left on the tire by a carless tire  mounting person. 

 

I noticed the tyre was spinning slightly when I pulled away and locking up when I braked--  If a rear tire was mounted backwards it could have one or the other of these but not both, but it would have to be pushed REAL HARD to get it to do either (something a Honda 125 is lacking on acceleration)

 

 

[Bluenoser]

1 hour ago, Rinkydink said:

The OP was about running it one direction then changing it, NOT installing it in the wrong direction initially. 

Correct.  

The tire, a Michelin Road 5, has about 9,500 km on it.  It is not quite to the wear marks on the LH side.  As I mentioned, I think the worn portion of the tire has very little if any capability remaining to be effective on a wet road.  I'm always extremely cautious when riding on a wet road even with new tires and even more so once the tires are showing any sign of wear.  Anyone that watches Formula 1 will know what happens when they stray outside of the dry line with slicks mounted, often instant loose of control.

Anyway, I have taken the tire off and turned it around.  I plan to put a few miles on it this weekend, practice a few hard braking events etc.

[Rougarou]

4 hours ago, roadscholar said:

 

Evidently missed the more important point, you absolutely have to have tread on your tires when it rains, it's what channels the water away from the contact patch that keeps you from hydroplaning. It's the only reason street tires have tread but it's a really important one. 

 

 

 

That's the idea, but Pat's seen the tires I ride/have ridden and the ones he saw had "plenty to me" tread, but I've zipped down the slab at 80 with the white strings showing through,.....mebbee I's lucky, but I slide none.

 

Engineers are no different than a lot of us, they just get funded better on software and supplies to come up with odd solutions that may be overkill........like removing nearly the entire front end of a vehicle to change an A/C compressor (not necessary) or the entire dash to replace a heater core (not necessary).  The only thing, in my opinion, that engineers do really, really well is create powerpoint slide decks

[TEWKS]

1 hour ago, Rougarou said:

Pat's seen the tires I ride/have ridden and the ones he saw had "plenty to me" tread

Yup, I seed them.  Good earlier point on car/truck tires, I was just recently asked if I wanted white letters out. I didn’t give rotational direction a thought. I’ll look for the arrow tomorrow.

[Hosstage]

White letters in, put the tire on the other side of the vehicle to get proper rotation...

 

Bluenoser, interesting experiment you have going there. Keep us updated on the wear pattern and performance.

[elkroeger]

No, I didn't miss the point.  I just disagree.

[Bluenoser]

Well I've ridden 950 km with the front tire installed with rotation arrows in reverse.  Practiced straight line emergency braking,  practiced braking in corners,  rode some of my favourite twisty rodes, rode a road that has a plethora of tar filled cracks.  No wet roads.  

I can not detect any change in performance or handling characteristics.  If this were a blind test I would not know which way the tire was mounted.  Perhaps someone more skilled than me could detect a difference.

I have a new tire ready but this one will remain installed as is until worn to the wear indicators.   If I were a commuter or heading out on a long ride with any chance of rain I would not chance it.