Blowouts

harringtonp

Blowout today, see image.

Mechanic reckoned that latex tubes sometimes get caught between rim and tyre when being pumped up after loosing pressure and can blow out the tyre sidewall or rim. The setup had been used several times before blowing out and as is usual with latex I'd pump up before use.

Any other suggestions as to the cause of the blowout, does this one makes sense ?

I like this tyre/tube combo for racing and am tempted to go for it if I thought care could avoid this happening again.

07Lapierre

If a tube is caught between the tyre and the rim, the tube will blow, not the tyre.
How old is the tyre in the photo? IMO it looks like an old tyre (the sidewall nylon treads are visible). I'd say the tyre failed first, which resulted in the tube blowing.

crosstownk

As above, the tyre failed. No way would a tube fail cause that damage to the tyre. The tyre gave out and the tube just expanded and popped.

Pretty catastrophic all the same. There's no booting that tyre!

From the photo, the tyre looks like it has seen better days.

harringtonp

Tyres were purchased Mar 13th and have been used less than 10 times.

It looks far worse after the blowout.

So you're telling me that a tube caught between tyre sidewall and wheel would never cause a tyre to blow out.

The tyres are Continental Grand Prix TT which are light and extremely fast though do have thin rubber. I only use them racing (after trying them out a couple of time).

One thing I have done is use baby wipes to clean them off after use. I presume these don't have weaken the structure, they are meant for babies arses after all !

harringtonp

Does this type of thing happen if a tube is excessively pumped ?

Intention was 120PSI but with a valve extender on the pressure gauge needle swings back and forth (loose some air as pumping) and its hard to tell what exactly the pressure is.

Alanstrainor

GP4000II tires are known to have a sidewall issue where they fail like this, I don't think yours are the same, but perhaps they are similar? I had a GP4000 fails after little mileage in this way. Wiggle replaced for free after I contacted them.

Alek

Looks like overinflation / manufacturing fault to me.

I'd compare my pump against another and if it seems fine, talk to dealer or write to Conti.

harringtonp

Request gone into mantel is see if there is cover

iwillhtfu

I've had numerous gp4000s11 fail on the side wall. I've never had a blow out like that but I've changed tyres as I believe they're being made with the side wall to thin.

I've switched to conti grand prix and no issues and the side walls don't have a visible thread pattern like the gp4000 do

AmberGold

Used Gran Prix for a few years, had 2 fail like that, micro cut in the sidewall and tube forced itself thru. One when I wasn't even riding the bike, it was in the hall and I heard a loud bang, relatively new tyre binned.
Having looked up a few sites at the time seemed a common enough complaint with Gran Prix.

harringtonp

iwillhtfu wrote: »

I've had numerous gp4000s11 fail on the side wall. I've never had a blow out like that but I've changed tyres as I believe they're being made with the side wall to thin.

I've switched to conti grand prix and no issues and the side walls don't have a visible thread pattern like the gp4000 do

Just so people don't confuse them. You're talking about

http://www.continental-tires.com/bicycle/tyres/race-tyres/grand-prix

The tire in picture that blew out is

http://www.continental-tires.com/bicycle/tyres/race-tyres/grand-prix-tt

Though they are all continental with presumably a lot of shared technology

iwillhtfu

harringtonp wrote: »

Just so people don't confuse them. You're talking about

http://www.continental-tires.com/bicycle/tyres/race-tyres/grand-prix

The tire in picture that blew out is

http://www.continental-tires.com/bicycle/tyres/race-tyres/grand-prix-tt

Though they are all continental with presumably a lot of shared technology

Yes I was referring to their high end tyres in general they seem to be very delicate.

This is the one I had numerous issues with.

http://www.continental-tires.com/bicycle/tyres/race-tyres/grand-prix-4000-s2

07Lapierre

I have 3 bikes and all 3 have Conti GP4000II and I have no issues with them. I think there a great tyre.

iwillhtfu

07Lapierre wrote: »

I have 3 bikes and all 3 have Conti GP4000II and I have no issues with them. I think there a great tyre.

Sure that's that so. :P

I have 4 bikes all with gp4000sII all with issues.

But seriously I used to be a big fan of them and they are a great tyre and still have them on two bikes but as said I've had numerous issues with them.

07Lapierre

iwillhtfu wrote: »

Sure that's that so. :P

I have 4 bikes all with gp4000sII all with issues.

But seriously I used to be a big fan of them and they are a great tyre and still have them on two bikes but as said I've had numerous issues with them.

Sorry for your trouble so.. I was just sharing my experience of Conti tyres ( which has been very positive)

Fireball XL5

Had a similar and recurring problem. Discovered that the brake block on one side was set slightly too high so that each time I braked it was rubbing off the side wall of the tire which resulted in a small almost imperceptible hole. On the final occasion the blow out ripped the whole side wall of the tyre apart.

Never made that mistake again.

Mr. Grieves

Fireball XL5 wrote: »

Had a similar and recurring problem. Discovered that the brake block on one side was set slightly too high so that each time I braked it was rubbing off the side wall of the tire which resulted in a small almost imperceptible hole. On the final occasion the blow out ripped the whole side wall of the tyre apart.

Never made that mistake again.

I did the same thing, front tyre blowout at 70km/hr! Check your pads and be aware that, if they're too high, they may not rub the tyre until a little lip has worn into the pad.

route66

Mr. Grieves wrote: »

I did the same thing, front tyre blowout at 70km/hr! Check your pads and be aware that, if they're too high, they may not rub the tyre until a little lip has worn into the pad.

Me too - albeit at 60 km/h. Posted here in late April: link

harringtonp

AmberGold wrote: »

Used Gran Prix for a few years, had 2 fail like that, micro cut in the sidewall and tube forced itself thru. One when I wasn't even riding the bike, it was in the hall and I heard a loud bang, relatively new tyre binned.
Having looked up a few sites at the time seemed a common enough complaint with Gran Prix.

Just like to clarify if it is a Grand Prix or Grand Prix TT you are talking about ?

harringtonp

Mr. Grieves wrote: »

I did the same thing, front tyre blowout at 70km/hr! Check your pads and be aware that, if they're too high, they may not rub the tyre until a little lip has worn into the pad.

Pretty sure this wasn't the case here, always spin wheels and check before riding

harringtonp

This has turned out a lot worse than expected. Thought it was only the tire but checked the rim today and it was been flattened for a 8cm stretch with sharper edges.

They're brand new carbon rims too, used less than 10 times. It looks like I could still fit a tyre under the lip but am wondering about the impact the sharper lip would have...

benneca1

Replace: if it is a front rim it will kill you when it fails if it is a rear you might get away with a spell in hospital. To get back to the GP 4000 issue I had a front wheel blow out last year with a brand new tyre one which was not pleasant. Put it down as one bad tyre as I generally like them. I check my front side wall every time I go out nowadays.

iwillhtfu

harringtonp wrote: »

This has turned out a lot worse than expected. Thought it was only the tire but checked the rim today and it was been flattened for a 8cm stretch with sharper edges.

They're brand new carbon rims too, used less than 10 times. It looks like I could still fit a tyre under the lip but am wondering about the impact the sharper lip would have...

That rim is for the bin I'd say.

You can see the carbon splintering and I'd say pumping a tyre up to pressure will cause the rim to bulge and eventually roll the tyre.

Apologies for creating the confusion with the tyres

magicbastarder

harringtonp wrote: »

This has turned out a lot worse than expected.

i'd assumed the tyre blew out when the bike was stationary - it blew out while cycling? i.e. it looks to my untrained eye that you slid along on the rim.

harringtonp

magicbastarder wrote: »

i'd assumed the tyre blew out when the bike was stationary - it blew out while cycling? i.e. it looks to my untrained eye that you slid along on the rim.

Probably did, was going downhill towards a roundabout and would have pulled brakes.

Matt Bianco

I experienced a front sidewall blowout yesterday evening in a race (luckily was towards the back of the main group when it happened). I've been running Conti Force & Attacks and had the same issue with a previous tyre after half a season but have only had this set on for <200km so surprising that it should give way so early I thought. I have checked the brakepads to see if rubbing, which it's not, and am running 100psi on front (I weigh 67kgs) so no undue pressure compared to previous 4000s used.

The last think I can think of is the rim which is smooth to the touch but wanted to ask what sandpaper you could use to ensure there's no nicks that could be causing this - wheels are alloy Zondas btw

harringtonp

I checked my other wheels and noticed vertical marks on the sides of the tyres on two of them, see images. The tyres are Michelin Pro3.

Are these what we call stretch marks and an early indication that the sidewall may go ?

The interesting coincidence is that I have not noticed these types of marks before on tyres and both these tyres (along with the continental grand prix tt that blew) have/had latex tubes inside.

I only recently started using latex tubes but am struggling to find any good reason as to why they would put more pressure on tyre sidewalls than ordinary 100g butyl tubes. Anyway mantel sent me out a free continental grand prix tt tyre and on reading the instructions with it you can clearly see that continental are not a fan of latex or light supersonic tubes. They highly recommend using their own standard race tubes.

Statler

harringtonp wrote: »

I only recently started using latex tubes but am struggling to find any good reason as to why they would put more pressure on tyre sidewalls than ordinary 100g butyl tubes. Anyway mantel sent me out a free continental grand prix tt tyre and on reading the instructions with it you can clearly see that continental are not a fan of latex or light supersonic tubes. They highly recommend using their own standard race tubes.

Are you saying that Continental recommend NOT using their own supersonic tubes? I used to use them with GP4000s tyres but stopped a few years ago after 2 stationary tube blowouts. Switched to Michelin latex since without any issue.

harringtonp

Statler wrote: »

Are you saying that Continental recommend NOT using their own supersonic tubes? I used to use them with GP4000s tyres but stopped a few years ago after 2 stationary tube blowouts. Switched to Michelin latex since without any issue.

Yes they specifically mention light and supersonic but I think its in the context of hilly terrain and carbon rims

Alek

I checked my other wheels and noticed vertical marks on the sides of the tyres on two of them, see images.

These worn areas happened due to rubbing, most likely against the frame. Perhaps your bike has tight clearances and tyres rub slightly against the frame when wheels flex in sprinting?

harringtonp

Alek wrote: »

These worn areas happened due to rubbing, most likely against the frame. Perhaps your bike has tight clearances and tyres rub slightly against the frame when wheels flex in sprinting?

Thanks Alek, that makes sense for the Krysium as it was rebuilt off center and needs to be fitted carefully with a tight skewer. With the other planetX wheel, rubbing is not something I was ever aware of but that doesn't mean of course that it didn't happen.