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.

Chips Lovell

Aside from the fact that carbon clinchers are a bad idea in general in my opinionl, you should never use latex tubes with carbon clinchers. Most manufacturers will advise against it.

cdaly_

harringtonp wrote: »

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.

Whatever about the tyres, those mavic rims are looking worn...

De Bhál

Jep Gambardella wrote: »

Aside from the fact that carbon clinchers are a bad idea in general in my opinionl, you should never use latex tubes with carbon clinchers. Most manufacturers will advise against it.

just wondering why you think carbon clinchers are a bad idea? I don't know much about them.

07Lapierre

De Bhál wrote: »

just wondering why you think carbon clinhers are a bad idea? I don't know much about them.

They get very hot under heavy braking. (Hotter than Alloy rims anyway). Latex tubes are very thin, so more prone to blowouts when they heat up.

De Bhál

07Lapierre wrote: »

They get very hot under heavy braking. (Hotter than Alloy rims anyway). Latex tubes are very thin, so more prone to blowouts when they heat up.

would this be something you'd worry about in the hills of this country or longer alpine type descents

07Lapierre

De Bhál wrote: »

would this be something you'd worry about in the hills of this country or longer alpine type descents

Depends on how good you are at descending! (Stay off the brakes)

iwillhtfu

De Bhál wrote: »

would this be something you'd worry about in the hills of this country or longer alpine type descents

I have carbon rims and for the most part they're fine on our descents but it's not really the gradient it's how much braking you use. If you're trailing the brakes while descending this will create heat.

Generally if I plan to go on a hilly route with a lot of climbing and descending I'll use different wheels. The carbon rims I have are deep section I use them mainly in Triathlon races but occasionally on a road spin. I've never had an issue with them over heating but I have experienced brake fade on a few spins.

Chips Lovell

De Bh103975684 wrote:

just wondering why you think carbon clinchers are a bad idea? I don't know much about them.

I don't think carbon is a suitable material for a clincher rim. As Lapierre says, they retain heat more than allot runs, increasing your chance of a blowout. And if you flat, there's a risk that the rim will get damaged through contact with the road surface, as happened to the OP.

iwillhtfu

Jep Gambardella wrote: »

I don't think carbon is a suitable material for a clincher rim. As Lapierre says, they retain heat more than allot runs, increasing your chance of a blowout. And if you flat, there's a risk that the rim will get damaged through contact with the road surface, as happened to the OP.

They're perfectly suitable as a clincher wheel or at least as much as a tub and I'd prefer a full carbon wheel than these laminated carbon fairing you see.

Anything carbon is easily damaged when dragged along the ground including your frame. If op had not of breaked to the point of skidding on the rim the damage may not have been as bad but I understand with a blowout the sudden reaction to jumping on the breaks.

jntsnk

If you do have a blowout does that just mean a puncture or the carbon rim be damaged as well

iwillhtfu

jntsnk wrote: »

If you do have a blowout does that just mean a puncture or the carbon rim be damaged as well

It depends how bad it is but generally the damage is done when the rim comes into contact with the road but yes it can blow out the sidewall of the rim.

Chips Lovell

iwillhtfu wrote: »

They're perfectly suitable as a clincher wheel or at least as much as a tub and I'd prefer a full carbon wheel than these laminated carbon fairing you see.

Anything carbon is easily damaged when dragged along the ground including your frame. If op had not of breaked to the point of skidding on the rim the damage may not have been as bad but I understand with a blowout the sudden reaction to jumping on the breaks.

I'd have to disagree with this. Clincher and tubulars rims are very different. With a clincher, the braking surface is directly next to the the tyre and tube. With tubulars, the tyre sits above it, away from the heat.

And yes, a carbon frame will be damaged if ground into the road but your wheels are the part of the bike that are in permanent contact with the road.

iwillhtfu

Jep Gambardella wrote: »

I'd have to disagree with this. Clincher and tubulars rims are very different. With a clincher, the braking surface is directly next to the the tyre and tube. With tubulars, the tyre sits above it, away from the heat.

And yes, a carbon frame will be damaged if ground into the road but your wheels are the part of the bike that are in permanent contact with the road.

Disagree all you like it makes it no more right to be honest.

You mean your tyres are permanently in contact with the road. By your logic the frame is equally in contact with the road as the rims.

It's also more likely you'll roll a tyre on a tubular due to heat build up let's not forget it's only glue securing your tyre to the rim. As for the breaking surface being away from the tyre on a clincher you are aware heat dissipates throughout the rim.

Anyway I digress. I disagree with your initial statement and having ridden both tubs and clinchers I would pick clincher over tub every time unless of course you've a team car following you everywhere.

Lumen

I came across this thread late after it was referred to from another.

I've read the contention that carbon clinchers are OK on descents if you know how to brake properly. I've probably even written that myself.

But I terminally warped my front carbon clincher last year descending Red Lane. It's a very technical, twisty and bumpy descent and it was wet which limited my opportunities for hard braking. It's possible that someone braver or more skilful could have managed it, but I couldn't despite being aware of the limitations of my rims.

So the idea that this problem requires "alpine" descents is not true, in my experience.

Of course it's likely that there was something wrong with the rim already. I was getting pulsing under braking since they were new, but this generation of wheels (2010 maybe) tended to do that. I did get lots of warning as the pulsing got worse over the descent, but I carried on going as I was curious to explore the failure mode.

After checking the rim at the bottom I cycled home very carefully. There was one more hill which I descended slowly using the rear brake only.

cdaly_

Lumen wrote: »

I came across this thread late after it was referred to from another.

I've read the contention that carbon clinchers are OK on descents if you know how to brake properly. I've probably even written that myself.

But I terminally warped my front carbon clincher last year descending Red Lane. It's a very technical, twisty and bumpy descent and it was wet which limited my opportunities for hard braking. It's possible that someone braver or more skilful could have managed it, but I couldn't despite being aware of the limitations of my rims.

So the idea that this problem requires "alpine" descents is not true, in my experience.

Of course it's likely that there was something wrong with the rim already. I was getting pulsing under braking since they were new, but this generation of wheels (2010 maybe) tended to do that. I did get lots of warning as the pulsing got worse over the descent, but I carried on going as I was curious to explore the failure mode.

After checking the rim at the bottom I cycled home very carefully. There was one more hill which I descended slowly using the rear brake only.

:eek:

doozerie

Lumen wrote: »

I came across this thread late after it was referred to from another.

I've read the contention that carbon clinchers are OK on descents if you know how to brake properly. I've probably even written that myself.

But I terminally warped my front carbon clincher last year descending Red Lane. It's a very technical, twisty and bumpy descent and it was wet which limited my opportunities for hard braking. It's possible that someone braver or more skilful could have managed it, but I couldn't despite being aware of the limitations of my rims.

There was a downhill racing event held on that hill a few years back. I had a brief conversation with one of the riders competing in it early on who, from what I recall, said he was a French former pro road racer.

My abiding memory of that day is seeing his bike summersaulting gracefully through the air (well, okay, it was graceful while in the air, less so each time it hopped off the ground) for the last stretch. I think it even reached the finish line. He didn't, he was in heap in the ditch, though I saw him again later and he seemed relatively okay (wearing a sling, but conscious and chirpy).

That descent takes no prisoners.

Alek

_Each time_ I find myself going down Red Lane I make promise to only ever climb it from now on...

Lumen

Racing on closed roads is easier on rims because you don't have to bee able to "stop in the space you can see to be clear and is likely to remain so", the only limit is cornering grip.

Obvs going faster brings other terrors.

On open roads you need to be going slow enough to stop.

Red Lane is particularly problematic due to blind bends and narrowness, plus the usual gravel and broken, bumpy surface. You may come round a corner to find the road fully blocked by cars negotiating a pass or a car ascending at speed in the middle of the road, in which case the hedge would look relatively appealing as a destination.

loyatemu

Alek wrote: »

_Each time_ I find myself going down Red Lane I make promise to only ever climb it from now on...

neither option is appealing TBH

Alek

neither option is appealing TBH

At least one has a proper HTFU quality, the other is downright butt clenching :pac: