weird bulge on tyre

[Pipboy2000]

Hi friends,

there's a bulge on the rear wheel, does it mean that I need to replace the tyre?
it gives unpleasant butt massage during cycling

[Jdsk]

Have you removed, inspected and tried reseating it yet?

Jonathan

[Brucey]

the tyre is not seated correctly. If you finish pushing the second bead over the rim at the valve (like you should) then you have to make sure the valve is pushed up out of the way before the last bit of bead goes over.

At present I suspect the tyre is sat on top of the valve part of the inner tube.

cheers

[Mike Sales]

It is significant that the "bulge" is at the valve. It looks to me very much as if the tyre beads are resting on the valve base thickening. Deflate the tube and endeavour by pushing the valve to work its base into the tyre, above the beads. Settle the beads into the rim well and pump away. Check, of course, but I think that all should then be well.

[Pipboy2000]

Have you removed, inspected and tried reseating it yet?

Jonathan

the whole story:
Day 1 : I noticed the vibration
Day 2 : I brought the bike to a service.
Day 3 : The guy told me that he replaced one of the spokes and did some tension changes with other spokes (that was the reason as he told me), he also replaced the inner tube (as I noticed later).
Day 3 : The bike was OK during my way from the service to my place.
A few days later (today) I decided to go for a ride and noticed that the wheel is flat. I removed the tyre and discovered that the inner tube is severely damaged (see another pic). I replaced the tube but immediately noticed the vibration again. Later on today I noticed that bulge, but haven't inspected anything yet since then.
I can go back to the service with it obviously but I don't want to loose no time any more.

Jonathan what do you mean by reseating?

[Pipboy2000]

thank you all for your suggestions, I will try.

[Jdsk]

Reseating: the part of refitting the tyre when you make sure that the bead is on the rim... correctly placed all the way round on both sides and nothing trapped underneath, as suggested above.

Jonathan

[rmurphy195]

Almost certainly caused by the base of the valve not being seated correctly in the rim

[mumbojumbo]

Simply solved if you follow excellent advice offered already

[2_i]

Push the vent half way or more into the tire, when there is no air yet, to pull the tube out of the space between the rim and tire bead. Start pumping with the vent still deeply in. It will come out of there by itself as you add more air.

[iandusud]

Always partially inflate the tube before fitting - just enough to support the tube, so that it fits inside the tyre and doesn't sit on the rim where it can get caught under the bead of the tyre as in the case here. BTW the failure of the tube in the photo is due exactly to this, i.e. when the tube was fitted it was trapped under the bead and has slowly under pressure worked its was out from under the bead and split.

[Marcus Aurelius]

Looking to the left and right of the ‘bulge’ I can see that the tyre appears to be seated correctly. I therefore suspect you have a tear at the bead / side wall failure. Interestingly it’s a Continental tyre, so if that is a bead tear ( I think it is ) I wouldn’t be that surprised. It’s often caused by using tyre levers to get the tyre on and off. If you do have to use tyre levers, be careful not to scrape the rubber at the bead. It’s best to use just your thumbs if at all possible.

[Marcus Aurelius]

Always partially inflate the tube before fitting - just enough to support the tube, so that it fits inside the tyre and doesn't sit on the rim where it can get caught under the bead of the tyre as in the case here. BTW the failure of the tube in the photo is due exactly to this, i.e. when the tube was fitted it was trapped under the bead and has slowly under pressure worked its was out from under the bead and split.

Nope. If that happens the bead tucks under, it doesn’t lift. What you’re describing is a common problem, which as you say is fixed by just pushing the tube up into the tyre by the valve, before fully inflating, but I don’t think that’s what’s happening in the O.P’s case. It looks like a bead failure / sidewall issue to me.

[Brucey]

FWIW if the tyre is intact and correctly sized (which I suspect it to be in fact) and the rim is good, the 'bulge' cannot appear unless there is also a corresponding 'dip' where the bead is in the well of the rim.

The thing that isn't obvious is that once there is both a dip and a bulge (even a small one), the arrangement is inherently unstable, i.e. the only thing stopping both the dip and the bulge from growing is simple friction. This arises because the growth of both together is accompanied by an increase in overall tyre volume, and is thus favoured. The most common thing is that the both grow as the bike is ridden and soon enough the innertube bursts through the gap and it is called (perhaps wrongly) 'a blowout'.

You can practically see the inner tube in the OPs photo, the tyre bead is so far out of position. I don't believe this is likely to occur without a corresponding 'dip'. If there is no 'dip' then the tyre and/or rim are badly sized or damaged in all probability.

cheers

[iandusud]

Always partially inflate the tube before fitting - just enough to support the tube, so that it fits inside the tyre and doesn't sit on the rim where it can get caught under the bead of the tyre as in the case here. BTW the failure of the tube in the photo is due exactly to this, i.e. when the tube was fitted it was trapped under the bead and has slowly under pressure worked its was out from under the bead and split.

Nope. If that happens the bead tucks under, it doesn’t lift. What you’re describing is a common problem, which as you say is fixed by just pushing the tube up into the tyre by the valve, before fully inflating, but I don’t think that’s what’s happening in the O.P’s case. It looks like a bead failure / sidewall issue to me.

I have certainly witnessed on several occasion (backing away rapidly and covering my ears) a tyre lifting off the rim followed by the explosion of the inner tube. This has been on new bikes which have had their tyres inflated to correct pressure. I have always assumed it was caused by a badly fitted tube as the remedy was always to fit a new tube (properly).