Wobbly back wheel

[si_c]

Remove the tire, spin the wheel check it's true. Then reseat the tire completely checking for damage as you go. Reinflate and check again. I had an issue similar to yours, removing and reseating the tire helped.

I think in my case it was badly installed and then slipped off the bead slightly.

 

[ColinJ]

I have just had a tyre start to break apart from the inside. The first thing I noticed was a bulge in the tyre. I didn't actually notice it when I was riding but I suppose if it had bulged in a different direction I would have.

I couldn't see anything with the tyre deflated until I flexed it (3rd photo) when the damage became obvious. The rubber was intact, but the carcass of the tyre under the rubber was broken, where that kink is between the red pen marks.

 

[Jody]

Either the rim is out of true or you have popped some chords/wire in the tyre wall. Easy thing to do if the wheel has took a hit. I have a few tyres that have done this. All seated correct but the tyre will go up down and side to side. Change the tyre front to rear and see if you still have the same wobble. If yes it's the rim if no its the tyre.

 

[mikeloveshisrockhopper]

Either the rim is out of true or you have popped some chords/wire in the tyre wall. Easy thing to do if the wheel has took a hit. I have a few tyres that have done this. All seated correct but the tyre will go up down and side to side. Change the tyre front to rear and see if you still have the same wobble. If yes it's the rim if no its the tyre.

I've got a few spare tyres so I'll try that first I think. Thanks all for your input.

 

[mikeloveshisrockhopper]

An update. I deflated the tire down to flat and gave it a good pinch and massage all over before pumping it up about 15psi at a time. When I got it to about 60psi, I spun it and it certainly looked better. Then I decided to let it down again, remove the tire and place the rim on the bike tireless. The rim is as true as the day is long. So I put the tire back on following the same procedure as last time. This time, I happened to notice that the wall area on some parts of the tire close to the bead looked a bit battered. When I fully inflated it, I spun it and bugger, the wobble was back.

So I took the tire off again and swapped it with an old but identical tire (Continental Travel Contact) and when I spun this, no wobble. The wall area close to the bead also looked in much better condition. So tomorrow, I will go for a quick spin and try to find a smooth downhill in the 20 minutes I'll have before work. I am feeling confident I have nailed it and my tire was cream crackered. I'll update you again later in the week.

 

[Globalti]

As I wrote above, the sidewall has failed. it's not uncommon.

 

[mikeloveshisrockhopper]

As I wrote above, the sidewall has failed. it's not uncommon.

You did fella, this has been a resourceful post. I'll treat myself to a couple of new tires if the ride proves the problem has gone.

 

[Ajax Bay]

Giant P-SL2 28-622 fail image. The first I knew about this sidewall bulge was a 'one zzztt a revolution' sound as the bulge started fouling the seatstay. The front had failed in a similar way 1000km earlier. Stupidly I had hoped the other one would be OK. 680km into an end-to-end it wasn't, at 6:15pm on Day 4,with an hour to go and sunset at 7:40. Note the failed threads.

 

[heliphil]

http://www.wheelfanatyk.com/blog/elasticity/ is interesting reading on the forces involved on a rim when the tyre is pumped up

 

[mikeloveshisrockhopper]

Ok, a cheeky 30K this morning with plenty of fast downhill stretches confirms the wobble is no more. My 8 year old tyre behaved like a dream. Off out to buy a couple of tyres. Thanks all, stay safe and Merry Christmas.