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tubie high speed blow out
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I was at IMUSA last week and experienced a blow out on the long downhill into Keene, I was doing about 40 when the rear went.No panic, the tire stayed on the rim ans I braked to a very controled stop ( good reason to ride tubies right Bunnyman??)

Here is my question. It was a new Cont sprinter, pumped up to 135 on a Hed trispoke whick has medal brake surfaces and tire seat. I was continually breaking going down this steep hill, feathering the rear brake often. POW it goes! When I stopped to change the tire I noticed that the wheel was HOT at the rim, quite warm honestly. I am wondring if the wheel heated up the tire to greater than its spec strength and it just popped. I was so anxious to get going, I gave the tire to a spectator and asked him to toss it for me and never did look at the tire.



Any thoughts out there?

Steve
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Re: tubie high speed blow out [tristeve] [ In reply to ]
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In Reply To:
I am wondring if the wheel heated up the tire to greater than its spec strength and it just popped.
Definitely not. The max pressure as rated by Conti is 170, and the burst pressure is way higher than that.
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Re: tubie high speed blow out [tristeve] [ In reply to ]
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Why all the braking, was there something in your way?? ;-)
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Re: tubie high speed blow out [Pooks] [ In reply to ]
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Pooks,



in my old age, I seem to be getting like a "old man" car driver!

It is a good thing tri bikes don't have horns!!!



Of course the real reason is that i had to slow down my over all time. It is so tough on thone young ego's when a old guy kicks their butt!!!!!!



Steve
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Re: tubie high speed blow out [Pooks] [ In reply to ]
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It might also have had something to do with the wind and the rain.
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Re: tubie high speed blow out [Pooks] [ In reply to ]
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That descent was hairy to say the least. The road was wet, there were gusty 25-30mph winds, cars coming up in the opposite lane and I was riding a disc ( I know, not the best choice). Even uberbiker Chris Lieto admitted he hit the brakes on the way down to Keene and felt he might lose control of the bike.
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Re: tubie high speed blow out [tristeve] [ In reply to ]
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"No panic, the tire stayed on the rim ans I braked to a very controled stop ( good reason to ride tubies right Bunnyman??)"

Correct. If a clincher went like that, we would be discussing this from your lap top in hospital, possibly.

It would have been something if we could have seen what temperature the rim was and how temperature affected your psi in the tyre. I don't think you were anywhere near the limits of the psi, even if you would have been pumped to 150. I doubt that there will ever be onboard electronics on bikes like they have in racing cars (particularly F1). The bicycle is too mechanically simple, even in the age of ten speed transmissions on bikes. It could happen, but it would seem (at this point) highly unlikely. Maybe I could start on temperature snesors at the brake pads...

Possibilities: tyre sidewall could have been so hot that a rock had penetrated. That one is kinda out there, but if the rim was as hot as you say it was (and the amount of braking was a contributing factor), then it could be the case. We have heard of the combination of a carbon rim, hot tarmac, and a tubular tyre rolling it off of the rim (i.e. Beloki). Usually, carbon rims retain more heat than aluminium ones.

My final analysis: freak incident.
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Re: tubie high speed blow out [bunnyman] [ In reply to ]
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Please forgive my ignorance (and for bringing this up as I'm going to guess that it's already been discussed repeatedly), but what are the benefits of a tubular vs. clincher?

Thanks in advance - Vogel
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Re: tubie high speed blow out [bunnyman] [ In reply to ]
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Mr. Bunny -

Q for you regarding tubulars - more specifically tubular clinchers like those made by Tofu. Are the general characteristics/performance similar to the regular tubulars? Would such a tire performed similarly in this kind of blowout situation? My guess is no. Comments?

JG
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Re: tubie high speed blow out [vogel] [ In reply to ]
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In Reply To:
Please forgive my ignorance (and for bringing this up as I'm going to guess that it's already been discussed repeatedly), but what are the benefits of a tubular vs. clincher?

Thanks in advance - Vogel


This is bunny's turf, but less hospital time -- if you do a lot of extreme road descents -- would certainly be one. :-)

Blow a FRONT clincher from an overheated rim, and it's far nastier.

(This very thing happened to me on a very steep/tricky section of the Gorbea (Euskadi/Pais Vasco/"Basque country") two years ago -- ugly, ugly, ugly).
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Re: tubie high speed blow out [vogel] [ In reply to ]
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Lighter, faster, safer in a blowout, and rolls a heck of a lot better. In that descent, if a clincher would have withstood that, it could have been a LOT uglier. There are two situations I have rolled a tubular on: wet glue, and underinflation. I could see a tubular rolling from a heated rim, but a clincher heated can be just as dangerous.
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Re: tubie high speed blow out [greenjt] [ In reply to ]
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The Tufo clincher/tubular may have stayed on the rim. I dunno. I basically wrote those things off quite awhile ago. I would rather have something much simpler to install, such as a real tubular tyre.
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Re: tubie high speed blow out [alpdhuez] [ In reply to ]
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Gads!!! How long were you laid up?

You said basically what I was going to say. You can generally roll to a full stop on a tubular- something that can be tricky and ruin the "hooks" of a clincher rim.
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Re: tubie high speed blow out [bunnyman] [ In reply to ]
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Formally checked-in style "laid up": just a coupla days (actually got off pretty light, considering!). And the rim was toast of course. Learned my lesson though -- even for non-race training, in the hills, clinchers simply aren't worth it. Period.

Flip side of the same equation: in this year's state championship TT race (dead flat, 40km non-technical course, super surface), flatted my front tubular ~8 miles from the finish. As was on a super ride and not carrying pump/spare, decided to soldier on, relying on that remaining thin rubber buffer between rim and road ended up winning age group title despite the flat. Try THAT on clinchers.

At a far, far higher level of competition, Indurain's teammmate Abraham Olano did the same thing (flat rear tubular) from about 5km out to win the Worlds road race at Duitama in Colombia ('94?).

So aside from cost (and even THAT ain't all that persuasive), the argument for clinchers would be????.....
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Re: tubie high speed blow out [alpdhuez] [ In reply to ]
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Is a tubular safer during a blowout than a clincher? If so why? Should I be riding tubular's all the time during training/racing?




"You're guaranteed to miss 100% of the shots you never take" - Wayne Gretzky
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Re: tubie high speed blow out [iseliw] [ In reply to ]
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Alpd! That ROCKS!!! And people around here think I am funny that all my new wheel sets have been tubies!

----------------------------------------------------------

What if the Hokey Pokey is what it is all about?
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Re: tubie high speed blow out [iseliw] [ In reply to ]
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In Reply To:
Is a tubular safer during a blowout than a clincher? If so why? Should I be riding tubular's all the time during training/racing?


The second part of your question is an individual choice of course, but few would argue that the answer to the first question you ask is "yes".

Why? It's simply the difference between continuing to ride on a ~ 1/8" thick, ~3/4" wide layer of rubber, or finding yourself suddenly "riding" on nothing but the edges of the metal rim itself.

If you're talking blowout (rather than slow leak), the latter is inevitable with clinchers. And the consequences (as described above) can be exceedingly unpleasant -- particularly if you're at high speed and/or descending.
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Re: tubie high speed blow out [tristeve] [ In reply to ]
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Here is a possible cause....if your break shoe is not properly adjusted it can rub the tire a bit instead of being completely on the rim and cause a blowout. I have personally adjusted my own (instead of a shop) ever since this happened to me.

David
* Ironman for Life! (Blog) * IM Everyday Hero Video * Daggett Shuler Law *
Disclaimer: I have personal and professional relationships with many athletes, vendors, and organizations in the triathlon world.
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Re: tubie high speed blow out [david] [ In reply to ]
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It looks like when I buy my zipp 404's for racing they should be tubular, doe s anyone here train on tubular's also, or should I stay with my stock Richey clincher's on my P2K for training.




"You're guaranteed to miss 100% of the shots you never take" - Wayne Gretzky
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