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Just had an MOT on my R1100S.
The MOT guy noticed that my rear tyre (Bridgestone Battlax) has been fitted the wrong way round.
He checked, but apparently this isn't an MOT failure, or even an advisory!

Can't say that I've noticed any poor handling & I'm tempted to take the lazy route & just leave it on, backwards way round.

Does anyone know of any good reason why I shouldn't take the lazy route?

Cheers

Stay below 88mph !

I confess that I don't know for sure, but two possible reasons come to mind:

1. Tyre is running against the direction of tread, therefore increased tyre wear.
2. Clearing water in the rain - I would think it would be more efficient to run in direction as designed.

Even the new Gatorskin tyres I fitted on the bicycle last week (and they're nearly slicks) has a direction of travel arrow stamped on each one.

Unless of course, it's a publicity stunt

First of all "well done" to the MOT bloke, not many that observant and conscientious .... er, thank goodness.
I'd definitely get it turned around, tyres are so important for keeping you on the road it's not worth the risk ... then there's the usual insurance aspect too.
Whoever fitted it wrongly should change it for no charge ?

i think it is to do with the way the rubber is laid on the carcass. Butt joint is angled so if the tyre is the wrong way there may be de-lamination at the feathered edge of the joint. I'd get it changed, there must be some reason for the rotation direction arrows or they wouldn't waste time and money having them in the moulds.

Humbug wrote:i think it is to do with the way the rubber is laid on the carcass. Butt joint is angled so if the tyre is the wrong way there may be de-lamination at the feathered edge of the joint. I'd get it changed, there must be some reason for the rotation direction arrows or they wouldn't waste time and money having them in the moulds.

+1....change it to how it's supposed to be fitted!

Here's a full explanation from someone at Avon Tyres -

"Before we can talk about directional arrows you must first understand a bit about tread patterns. There are many different tread patterns but there is one main reason to have any tread and that is to disperse water. (dust, dirt)

A tread pattern can be designed to disperse more water by making it rotate in only one direction. Thus, the need for directional arrows. The arrow tells you which way to mount a tire for maximum water dispersal. Another, less apparent reason for directional arrows is the tread splice.

What is a tread splice? When a tire is manufactured the tread portion of the tire starts out as a long flat strip. This strip is wrapped around the tire and the two ends are cut on an angle so one end overlaps the other rather than having square cut ends.

This overlapping point or splice offers a bigger surface area to bond together, rather than the small surface area provided by square cut ends. (Imagine gluing your fingertips together, as opposed to gluing along the entire length of your fingers laid on top of each other. Like an angled splice, the overlapping fingers result in a much stronger bond).

To further ensure the strength of this bond along the tread splice the directional arrow will show you which way to mount the tire so that when the rider is “on the gas”; the acceleration force on the rear tire is pressing the splice together, rather than peeling it back.

As for braking, 80 % of the braking should take place in the front on most bikes. Therefore, the front tread splice is run in the opposite direction than that of the rear, so when the rider is on the brakes, he’s not peeling the tread splice back.

If you are using a tire that has a directional arrow for rear rotation only and for some reason you want to put it on the front, make sure it is rotating in the opposite direction so you don’t aggravate the tread splice."

Pete

I’d change for no other reason than: It has been noted on the advisory? And In the event of an off, possibly involving a 3rd party - you could end up in a whole heap of problems.

After reading all the posts I decided to get the rear tyre refitted.
The R1100S has a belly pan so I loaned my ABBA stand to the mechanic to make rear wheel removal easier.
He hadn't used one before, so I gave him basic instructions on how to use it.
But......
Don't think he tightened it all up properly....
And.......
My lovely R1100S fell off the stand and broke the left side fairing....
AAAAARRRGGGGGHHHHH.......

I always take the wheels off to give to the tyre fitter and also put two large marker pen arrows on the rim for rotation direction .
Even so I had to tell one guy to go back and do it again to get the direction correct before I left.

SP250 wrote:I always take the wheels off to give to the tyre fitter and also put two large marker pen arrows on the rim for rotation direction .
Even so I had to tell one guy to go back and do it again to get the direction correct before I left.

John, why hire a dog and do all the barking yourself? This is definitely a scenario for fitting your own tyres. It is not rocket science.

So sorry for that awful falling down experience. Not good.

Chris

Chris
Re hireing a dog and barking myself.

I do it so I can check the tyres are fitted the correct way round and then that the right torque is used to re-fit the wheels.
With conventional forks there is also a correct order to tighten up clamp bolts and spindle nuts etc. so the legs aren't pulled out of alignment and cause stiction.
I also do a wheel bearing, caliper and pad check at the same time.

I don't care who I'm going to upset - If I am going in to hospital for a knee/arm/bollock operation................

I'll be marking the correct item with a big permanent marker - I don't care if it's the hospital staff's job.

Funny you should say that Al.

Went in for a tendon operation 30 years ago and they started shaving the back of the wrong hand.
It took a bit of an argument with the nurse before she believed me that she was wrong!

Had a similar argument with the surgeon about 3 years ago in an op, when he said he was going to start cutting (it was under a local anesthetic) and I told him to stop because I could still feel my hand.
He didn't beleive me, so he stopped and did a test with a needle and a blunt object.
He was amazed that I could still identify where, when and which object he was using (I couldn't see with a curtain up) after two injections.
So I got two more anesthetic injections and we waited till they took hold.