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'brifter' is f'ing stupid
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Need help. I'm trying to install a new GP 4000, and as soon as I pump it up to 100 PSI, it blows off the rim and the tube assplodes.
This has never happened to me before, but I just ruined 2 new tubes.
What can I do?
you can stop pinching the tube between the tire and the rim. install the tube properly and it won't assplode.
 

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A wheelist
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11,324 Posts
You can't figure out that you're leaving tube under the bead of the tire? :eek:

Tips - Talc tube. Inflate via mouth before installing. Put in 20lbs and push tire away from rim both sides, all round to check for tube under bead. Check sidewall molded line is concentric with rim edge. Guaranteed results.
 

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I concur with what others have said. 99% sure that you are pinching the tube under the bead. But you might also have a tire with a stretched/defective bead. If that was the case then it would go onto the rim "too easily".
 

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Road & Trail Warrior
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1,858 Posts
Discussion Starter · #6 ·
"you can stop pinching the tube between the tire and the rim".
"You can't figure out that you're leaving tube under the bead of the tire?"
OK guys, I can sense the sarcasm, and because this is the internet, you get a pass for lack of tact.

I've been changing tires for 20 years, and this has never happened to me, let alone, twice in 15 minutes. I thought someone might know about a possible common problem with GP 4000s. This is my first try with these. The bead is much tighter than any tire i've used in the past, so yes, it's probably pinching.

I DO appreciate your help and I'll try your suggestions.
 

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'brifter' is f'ing stupid
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15,659 Posts
in all seriousness if the tube goes 'bang' (and there isn't a hole in the tire big enough for the tube to push out) it's your fault for not installing it correctly.

people think of changing tubes as one of the biggest no brainers but if you mess it up the consequences are huge. when i was working full time for pro teams, we'd have various part time guys help out at certain races. one thing i would never let them do is install tubes/tires. i did ALL tube/tire installs. you may have been changing tires for 20 years, but it's obvious you've been making mistakes that should be easily caught. make absolutely sure the tube is totally contained inside the tire before inflating. every time. no fail.
 

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I always now put a little air in and go back around both sides of the rim for a check, put a little more air in and double check the rim again. I watch the tire pretty close until around 80psi and fill it slowly until done.
 

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Anphaque II
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6,176 Posts
in all seriousness if the tube goes 'bang' (and there isn't a hole in the tire big enough for the tube to push out) it's your fault for not installing it correctly.

people think of changing tubes as one of the biggest no brainers but if you mess it up the consequences are huge. when i was working full time for pro teams, we'd have various part time guys help out at certain races. one thing i would never let them do is install tubes/tires. i did ALL tube/tire installs. you may have been changing tires for 20 years, but it's obvious you've been making mistakes that should be easily caught. make absolutely sure the tube is totally contained inside the tire before inflating. every time. no fail.
Very interesting.


Either I've been doing it properly subconsciously or have been lucky for the past 40+ years.

I guess if you learn to do something properly and do it year after year since childhood, you do it correctly without thinking about it.
 

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'brifter' is f'ing stupid
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the whole thing started the morning of the first stage at the tour of georgia in '05 i think. we were putting some just-delivered tires on the race wheels for the day and one of the part time guys had one go bang when inflating it. the riders were all sitting around waiting to ride to the start and you should have seen the looks on their faces. at one point or another that day every one of them asked that only i would do tire installs.
 

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A wheelist
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11,324 Posts
the whole thing started the morning of the first stage at the tour of georgia in '05 i think. we were putting some just-delivered tires on the race wheels for the day and one of the part time guys had one go bang when inflating it. the riders were all sitting around waiting to ride to the start and you should have seen the looks on their faces. at one point or another that day every one of them asked that only i would do tire installs.
They weren't all on tubulars? :eek:
 

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'brifter' is f'ing stupid
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15,659 Posts
They weren't all on tubulars? :eek:
nope. i was loving it that year. not on tubular. mavic was the wheel sponsor and maxxis was the tire sponsor. we used the ONLY pair of cosmic carbone tubulars in the country on the dalton-dahlonega stage, but the tires were already mounted. even our discs that year were clinchers. 8 guys at the TdG, 2 flats...mavic got to both of them before we did so i never had to get out of the car.
just slightly different from last year...when i mounted 40 tubulars in one day in march. i was buzzed for days...
 

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A wheelist
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nope. i was loving it that year. not on tubular. mavic was the wheel sponsor and maxxis was the tire sponsor. we used the ONLY pair of cosmic carbone tubulars in the country on the dalton-dahlonega stage, but the tires were already mounted. even our discs that year were clinchers. 8 guys at the TdG, 2 flats...mavic got to both of them before we did so i never had to get out of the car.
Oh wow! I don't imagine there are too many top-end racers on clinchers anymore eh?

i mounted 40 tubulars in one day in march. i was buzzed for days...
I can imagine the high! :yikes:
 

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'brifter' is f'ing stupid
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15,659 Posts
Oh wow! I don't imagine there are too many top-end racers on clinchers anymore eh?


I can imagine the high! :yikes:
no, there are very few 'real' pro teams using clinchers. that year was due to maxxis sponsorship, the next year it was michelin. i know there are some michelin tubulars in europe that pop up every now and then. pretty sure they're actually michelin and not something else w/ a hot patch logo. there may be one protour team on michelin, but i'm not sure whether they use clinchers all the time or not.

i rode some carbon clinchers today w/ a michelin pro4 service course 25mm on the back (actual width on this rim is 27.8mm) and a bontrager 25mm (26mm) on the front. both tires at 80psi. such nice ride quality!
 

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A wheelist
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11,324 Posts
i know there are some michelin tubulars in europe that pop up every now and then. pretty sure they're actually michelin and not something else w/ a hot patch logo. there may be one protour team on michelin, but i'm not sure whether they use clinchers all the time or not.
Between 1974 and 1986 all I used (here in Canada) were Michelin tubulars for training (Clement for racing) but I haven't heard of them since. Not that I pay any attention as I've used clinchers since then.

i rode some carbon clinchers today w/ a michelin pro4 service course 25mm on the back (actual width on this rim is 27.8mm) and a bontrager 25mm (26mm) on the front. both tires at 80psi. such nice ride quality!
I feel about the same over my 25mm Vittoria Open Corsa Evo CX - sheer pleasure.
 
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