Tyre warp?

padyjoe

I bought 2 folding Conti Grandprix over a year ago.
One of them was on front, served me well, wear indicator still showing, lot of cracks in rubber but fine. The other one was a rear tyre, had to get it off after a while because started limping. (like this: roll-roll-limp-roll-roll-limp, so on.) It's a side to side movement. The rim is ok. I thought it happened due to tyre rubbing mudguard causing it to warp.
Got new sets of tyres lately so the front one went to rear. Same again, after 300 kms, it started limping.
Never had this with 2 different Giant clinchers and hopefully the new folding Duranos won't end up 'dancey' too!

JBokeh

in the area where the tyre has gone out of true is there damage to the surface on the sidewall? I've had mountain bike tyres go wobbly after damage to the sidewall,causing a cut thread in the casing of the tyre

padyjoe

Kinda. It's not a damage rather wear: what I noticed on the 2 tyres that the ply is showing on them. The rear one was rubbed on the shoulder, nothing major but enough for throwing off true, the front one has bead damage, tyre stretched beyond, about 3cms ply revealed. I take pics later.

You gave me a good pointer, thanks! It's a normal tear and wear I suppose.

magicbastarder

are your rear brake pads aligned properly? the damage seems to occur when you put the tyre on the rear wheel, if i read you right?

padyjoe

I've done 300kms since, if the brakes had not been ok I'd have had blowouts?

Pics attached.

magicbastarder

you should take a photo with the wheel on and the brakes pulled. that damage is very close to where the pad would rub against the tyre if it was misaligned.

cython

Also, post a picture of the profile of your brake pads, i.e. basically looking through the calliper along the the length of the pad - would really not be surprised to see that the pad is misaligned and even a lip formed/worn on the brake pad based on the tyre's appearance.

padyjoe

Here are the pictures, the cut on the left. To me it's not misaligned or 'lip-worn'.

cython

padyjoe wrote: »

Here are the pictures, the cut on the left. To me it's not misaligned or 'lip-worn'.

It might just be me, but the one in the image named left looks like the brake pad might be sitting a little high on the rim. As you say, no sign of uneven wear on the brake pad, but that does also look to be the side of the tyre where you're experiencing that sidewall wear in the earlier image.

padyjoe

Ok, thanks! It's time for re-adjusting the brakes. (I tend to set them high.)

Rubs like that won't go unnoticed while braking. I did not experience anything strange.

(The tyre could be beyond the best by date as well, 5-7k on it, got enough from rough roads, used in performance mode, handling a gross weight of 110kgs.)

padyjoe

Here are the brakepads, I don't see any unusual patterns.