Tyre wear question

[MarkW]

I've seen this sort of wear pattern on a number of tyres over the last 30 years. It has generally been caused by tread flex under load. Your XS11 is not light and the front tyre is not overly large. Under moderate to heavy braking the front tyre tread will flex and the leading edge of the tread blocks tends to be worn away at a higher rate than the rear section of that particular tread block. Similarly on grippy surfaces with spirited cornering a similar result can occur laterally for the same reason. If the front tyre pressures are a fraction low this effect is increased as the slightly lower pressure results in slightly more tread block flex. Softer compound tyres also increase this effect. As does extra road surface heat.

Handling won't deteriorate too badly until the tyre is well worn but when it does deteriorate it will probably give you a good steering head shake.

The cure ...... probably a slightly harder compound tyre and really careful attention to tyre pressures. You may not be able to stop the effect completely without resorting to horribly hard tyres - but that then reduces the grip factor and thus your safety margins. Life is a compromise.

For myself, I'll opt for the better grip and accept that I'll need to change a tyre before it becomes illegal tread depth wise.

[homer]

small price to pay since the front last at least twice as long
try pumping it up to about 38 - 40 psi

[Bonez]

small price to pay since the front last at least twice as long
try pumping it up to about 38 - 40 psi

It's a 19inch tire. They're not designed for those sort of pressures. It'd make riding on the XS11 dangerous to say the least. 30psi may help.

[Subike]

I've seen this sort of wear pattern on a number of tyres over the last 30 years. It has generally been caused by tread flex under load. Your XS11 is not light and the front tyre is not overly large. Under moderate to heavy braking the front tyre tread will flex and the leading edge of the tread blocks tends to be worn away at a higher rate than the rear section of that particular tread block. Similarly on grippy surfaces with spirited cornering a similar result can occur laterally for the same reason. If the front tyre pressures are a fraction low this effect is increased as the slightly lower pressure results in slightly more tread block flex. Softer compound tyres also increase this effect. As does extra road surface heat.

Handling won't deteriorate too badly until the tyre is well worn but when it does deteriorate it will probably give you a good steering head shake.

The cure ...... probably a slightly harder compound tyre and really careful attention to tyre pressures. You may not be able to stop the effect completely without resorting to horribly hard tyres - but that then reduces the grip factor and thus your safety margins. Life is a compromise.

For myself, I'll opt for the better grip and accept that I'll need to change a tyre before it becomes illegal tread depth wise.

thanks mark, that makes a lot of sense to me.
The road to work (30k) has a nice s bend in it that I have yet to get the pegs down on yet, , its marked 85 and im getting 140 in and 150 out
the surface is chip seal, so is agressive like you say.
Its a very open crn with heaps of camber as well,
So I will probably just be looking for a new tyre sooner than later.
be interesting to see others ideas

[Subike]

It's a 19inch tire. They're not designed for those sort of pressures. It'd make riding on the XS11 dangerous to say the least. 30psi may help.

lol
I agree with you there for sure......I want grip not slide,
bugger the speed it wears at, just interested if it was something else in the bikes set up. I'll try another 2lb pressure, but that would be the limit I think.

[Bonez]

lol
I agree with you there for sure......I want grip not slide,
bugger the speed it wears at, just interested if it was something else in the bikes set up. I'll try another 2lb pressure, but that would be the limit I think.

Another thing to consider is when these bikes where new the generally tires had thicker wall thickness and a lot harder compound .

Used the Shenkos on the front long? What do you think of them in general?

[BBzz]

ok, so this thread answers the "wear more on one side problem", Not that I have that yet, but understand the cause there of, road camber.
I have read the other thread re the "cupping" of tyre, but that was about a rear tyre cupping if I am right,
So what if it the front tyre that is "cupping"?
My Tyre wear issue?
There is a 1 - 1.5 mm taper from the front of the tyre block to the back of the tyre block.and is heavier wear on the centre of the tread area as opposed to the outer edge,sidewall edge
Tyre Shenko 100/90/19 57H
Tyre is at 28psi, this is on my 79 XS1100 yamaha.
The trye is no more than 5000k old.
Is there a cause for this?
Bad tyre construction,forks need maintenance,front rear shock balance wrong.
The rear shocks are set at minimum, and I only weigh 70kg, never carry a pillion, rear tyre 3500k old - even wear across its face.
Bike is only riden on the open road.
I hope this pic will help to sort this out.

Had the same sort of wear on my FZR1000 Bought the bike as an import, front tire was like new. Put a new rear on and after about 1500ks hard riding started to have the same sort of wear as you have described.
May be mine was that I put a softer compound tire on the rear and it was trying to push out the front, if you known what I mean? Some one also said that if the front tire was sitting around for a long time it could cause the same sort of wear after you start using it again. Hummm have now got a match set of Metzeler’s on and both wearing even and know feathering on the front so it wasn’t the bike setup.

[Subike]

Had the same sort of wear on my FZR1000 Bought the bike as an import, front tire was like new. Put a new rear on and after about 1500ks hard riding started to have the same sort of wear as you have described.
May be mine was that I put a softer compound tire on the rear and it was trying to push out the front, if you known what I mean? Some one also said that if the front tire was sitting around for a long time it could cause the same sort of wear after you start using it again. Hummm have now got a match set of Metzeler’s on and both wearing even and know feathering on the front so it wasn’t the bike setup.

the tyre is max 2 years old,
So I dont think it has hardened from age .
I have been practicing cornering on the Scargil Valley road and I am now able to corner a lot faster than I ever have.
Many thanks to the threads about countersteering etc, plus having been TEC on a few KB rides I have pushed far outside my old comfort zone. Much to my enjoyment.
Pleased with your statement about the set up of you ride not being the reason for the wear. May be I am just riding the XS11 a bit more agressivly that others would.
But she is fun

Bronz.
Shenko tyres?
I chose them because of the comments about them being a hard walled heavyer tyre, with a not so high spped rating.
Concidering The XS11 is a very heavy bike, my thoughts were that these would be better suited to the weight of the bike.
That weight makes them work. But at the same time, wet weather riding is not for pushing the safty envelope and I hesitate at trying to push Shenkos in the wet.
I think that a ditch or bank would be the result of that.
Otherwise, they heat up quickly and , in my limited experiance, have not as yet shown any lack of grip.
But then I also dont crner as fast as others either.

[MarkW]

On the subject of tyre pressures......

bikes, tyres and riders vary as do the seasons.

manufacturer's recommended pressures are and average suggestion for average users in average conditions.

A system that works for motorcycles and cars to find suitable road use pressures is as follows:

take your tyre pressures front and rear before you go for a ride;

do your ride at your normal pace in the normal manner for you - the ride needs to be at least 20km in distance;

as soon as you have completed the ride take your tyre pressures again WITH THE SAME TYRE PRESSURE GUAGE;

the pressures should have changed as when the tyre flexes in use it generates heat abd heat makes the pressure rise;

if the pressure has risen by MORE than 4psi that tyre is underinflated for your use. The soft tyre is flexxing too much and generating too much heat. Add a couple more pounds of air pressure to that tyre WHEN THE TYRE IS COLD.

repeat the pre ride pressure test, do the ride and recheck the pressure.

a reasonably correctly tyre should increase pressure from cold to hot by between 2psi and 4psi.

if the pressure rise is less than 2psi then the tyre is overinflated and not flexing enough and pressure should be reduced by 1psi at a time and the ride repeated.

keep repeating the process until both tyres are achieving similar pressure rises from cold to hot.

Being a fussy rider my tyre pressures alter between summer and winter by a couple of pounds - more pressure in the summer; thay also alter on the load being carried - more load needs more pressure.

A change of brand, compound or tyre size can also result in a minor alteration to tyre pressures.

I did 230,000km on my last bike and once I had found a tyre brand and size that suited the way I ride I stuck with them. Meant that having found good tyre pressures for me I didn't have to do any more re-setting!

Having found YOUR suitable tyre pressures front and rear, if, having taken your gloves off as soon as you stop after a decent ride, you feel each wheels tyre tread with the palm of your hand similar temperatures front and rear should be present. The hotter tyre (if they are different) will be the tyre that has been working harder or the one that may be slightly underinflated. Correctly working road tyres will feel definitely warm (but not HOT) to the hand.