Author Topic: Middle of the front tyre rises (Read 1416 times)

bonne · « **on:** May 21, 2023, 11:47:48 »

It might not be that clear on the photos, but the middle of my front tyre are riding. The tyre shop noticed it while changing the tyre last time and said that it is probably because of bouncing tyre. They checked the shock, nothing wrong. Then they said that it might be because of my large wind screen and large top box.

tyre inflation is correct.

What do you think? Can it help if I adjust the shocks, and if so, should they be harder or softer?

Bike is mostly loaded near max.

Should I just ignore it, or works some Tyres be better than others on this matter? I now run Bridgestone T41

nigel s · « **Reply #1 on:** May 21, 2023, 13:28:46 »

From the pictures it's hard to say but it sounds like cupping.Some tyres do this, one edge of the groove wears differently to the other.It doesn't usually affect handling until tyres wear down and the white lineing comes earlier than a tyre that doesn't cup.

bonne · « **Reply #2 on:** May 21, 2023, 14:30:35 »

If I google cupping, it looks as only a portion is rising. My Tyres is rising all around the tyre (in the middle)

And correct... I can't feel it when riding. But I guess that it will wear the tyre faster and maybe dangerous in extreme situations?

nigel s · « **Reply #3 on:** May 21, 2023, 15:08:34 »

If you can feel it when riding then the tyre needs to go.
However be aware once spotted one can focus on a problem that is not there ,the mind is funny like that.
Confidence in the tyre is paramount if you are not happy change it.

bonne · « **Reply #4 on:** May 21, 2023, 15:32:30 »

But changing the tyre will just make it happen again. I think of what is causing it. Too low pressure on the front making the tyre jump? Can I adjust the shocks to avoid it again? Or something else - should I go back to the original wind screen?

nigel s · « **Reply #5 on:** May 21, 2023, 15:47:02 »

Check the bike is set up to the settings recommended in the manual for your loading, tyre pressures, shock settings and fork settings. This is not always correct even when new.If all is set OK then the tyres don't suit your use and you need to change to another tyre type/manufacturer. The screen is not a problem here.
Do you ride hard ,off road ,two up ,slow, back roads or motorway, all these will inform your choice as to tyres.

purplebikeunicorn · « **Reply #6 on:** May 21, 2023, 20:51:54 »

Do you mean like the centre portion of the tread is raised, compared to the sides, like a band round the whole tyre?

I'm sure I've read that they use a harder compound in some tyres on the central band, to prevent premature wear when riding long straight roads. I've got a similar thing to how I describe on my rear tyre, only slight, but you can see it when the tyre is dusty. Doesn't seem to affect handling at all.

grumps · « **Reply #7 on:** May 21, 2023, 20:54:35 »

This happened on a Tiger 800 of mine. The shoulders wore out faster than the centre. It didn’t seem to affect handling.

bonne · « **Reply #8 on:** May 22, 2023, 05:56:25 »

Yes, it is like a rubber band around the tyre.

I am not cornering heavily, so it is hard for me to think that the sides are worn out faster then the center. The tie bloke explained it as the center is rising

nigel s · « **Reply #9 on:** May 22, 2023, 06:10:04 »

The T41 is a dual compound tyre so that is probably what you are seeing, nothing to worry about.When it wears out you can choose a different set if it bothers you.

NeilM · « **Reply #10 on:** May 22, 2023, 06:21:55 »

I didn't know it had a name but I suffered cupping with the front tyre of my 650 when I first got it. It was fitted with Battlaxe something or anothers and the handling was pretty horrible / terrifying.

At first I thought I'd made a terrible mistake buying one of these new fangled ADV bikes, but all the reports I had seen on the VStrom were overwhelmingly positive. Ryan F9 put me onto the issue in the end. In one of his videos he mentioned asymmetric tyre wear, off I went to the garage steel rule in hand and yup, that was it.

A change to Avon Spirit ST's and here we are 12,000 happy miles later.

nigel s · « **Reply #11 on:** May 22, 2023, 06:25:59 »

Love ryanf9,amazing vids
And isn't a T41 also a russian tank?
ho hum

Barbel Mick · « **Reply #12 on:** May 22, 2023, 09:41:04 »

I've got Battlax A41's on mine & I've just had a look.........
They also have that 'raised' section around the centre of the tyre. I have never noticed it & can't really see it but you can feel it when you rub your finger over the tyre.
I presume, as stated, a dual compound and it's normal.

Brockett · « **Reply #13 on:** May 22, 2023, 11:45:34 »

Dual compound tyres - harder in the middle softer on the edges to give better mileage. However if the bike is "loaded" maybe the tyre should be pumped to slightly higher pressure. That said I don't like Bridgestone dual compond tyres. I have had to change these tyres when the profile showed the centre has become raised and "lumpy".
Many years ago on my 350 Jawa the front tyre tread looked like a chisled pineapple chunks each one worn down at the front and not at the back. This was causes by under damped front forks (actually almost no damping at all) Dunlop K70's and 15wt oil cured that problem.

Upt North · « **Reply #14 on:** May 22, 2023, 13:28:15 »

I'm scratching my head just a little, doesn't it look normal.
(Where did all this sawdust come from).
Firstly they're T32's aren't they?
As above it's dual compound and it's doing what it should, resisting excessive wear in the centre of the tyre, I can't see cupping.
Are you running Bridgestone or Suzuki recommended pressures? Use Bridgestones if you aren't already. I think it's 36-41(?) Someone posted it recently but it'll be on the BS site.
If you're running heavy all the time you'll need more preload and maybe a little more damping. This will be covered in the riders manual.
Good luck and ride.
Upt.

bonne · « **Reply #15 on:** May 22, 2023, 17:58:13 »

Ah yeah... T32, sorry

According to the tyre bloke, it is not normal.

nigel s · « **Reply #16 on:** May 22, 2023, 18:25:05 »

Trying to remotely diagnose your tyre is not going well.Maybe a second opinion your end is called for.Take it to another tyre fitter and see what they say.But you could be seeing problems you admit you can't feel in the bike.But safety first, I predict that if a change to a different type of tyre is the only thing that will give you your confidence back. so be it.
Ride safe good luck

purplebikeunicorn · « **Reply #17 on:** May 26, 2023, 20:55:23 »

Brockett, I think it is expected to increase tyre pressures if you change the amount carried on the bike, as per the tyre pressure label changing rear tyre pressures for two up riding.

I'm already a couple of PSI higher than the solo rider values because I'm fat, and normally have the top box on!

Brockett · « **Reply #18 on:** May 27, 2023, 12:05:55 »

I had Bridgestone tyres on my Kawasaki 1000 SX and ran them at the specified pressures. The front tyre "fell off the cliff" at 2400 miles and the steering was not at all good. The dealer said that mileage was about normal for that bike. My S/H KTM 690 came with 3100 miles on the clock and the front Bridgestone was awful with a hard and bumpy ridge on the middle 25mm. What made it worse was that the "bumpy ridge" wandered from side to side. Now fitted with a pair of Avons that feel so very nice although they have only got 1500 miles on them so far.

NeilM · « **Reply #19 on:** May 28, 2023, 06:19:07 »

My Vstrom 650 had exactly the same issues as Brockett's KTM.

I don't know how many miles the Bridgstone's had done, they still had plenty of tread, but the wear patterns were all over the place and made for a pretty 'interesting' ride.

Just booked the bike in to have a new set of Avon Spirit ST's fitted at the end of next month.