Wonky GP4000 Clinchers?

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billspreston
Posts: 351
Joined: Tue Jun 30, 2009 7:40 pm
Location: CA

by billspreston

I bought 6 GP4000 S II 25c tires from a reputable online store. All 6 of these tires mount up extremly off center to the point that it causes clearance issues on tight frames. Anybody have similar issues with these tires? Im located in the US and bought the tires from Europe so probably not worth the trouble of returning them, but I'm pretty put off...

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Calnago
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by Calnago

Six tires all off center? Sure it’s not the wheel? Have you tried mounting them on a different wheel just to confirm it’s the tires?
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AJS914
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Joined: Tue Jan 28, 2014 6:52 pm

by AJS914

I'd check if they are all off center in the same spot.

billspreston
Posts: 351
Joined: Tue Jun 30, 2009 7:40 pm
Location: CA

by billspreston

Cal - yes, I'm quite sure. I'm now running a Vittoria Corsa Control on these wheels and they are perfectly straight. I mounted the tires on other wheels and they were still off. Given that the GP4000 are directional, they are all skewed towards the same side (drive side). Its like it was a bad batch as I purchased the 6 tires together at the same time.

vanillaflyweight
Posts: 37
Joined: Thu Aug 10, 2017 5:54 am

by vanillaflyweight

It could be something as simple as that was the fold point when boxed, hence why all in the exact same spot.

If you can I would try doing a test ride first, sometimes this is enough to get the tyre to sit right.

alcatraz
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Joined: Mon Aug 29, 2016 11:19 am

by alcatraz

There is a trick to alleviate this. I have a wheel where the clincher hook bulges outward ever so slightly in one spot. A normally mounted tire would automatically swing sideways and bulge in the same direction.

What I do is I check where this happens and turn the wheel 180 degrees from this spot. There I start pinching the tire and twisting it side to side. I'm pulling it as much as I can to try and concentrate the slack on the opposite side of the wheel. I pull and twist the tire on the other half side of the wheel.

I also try to push the bead down on the bulge side to make sure no slack is there.

Then after inflating you will notice the bulge is much smaller. This lets me use a rim that isn't perfect without issues. (It's one of my deeper rims I use for flat road rides. I wouldn't recommend doing this on climber rims where braking is extremely important. Replace rim if damaged.)

/a

yltman
Posts: 20
Joined: Tue Nov 21, 2017 12:50 pm

by yltman

I have not seen a single normal conti tire ever
at best it is a curved or wonky
mine (6 conti gp4000ii and my friends 2 gp4000ii and pair of force/attack) was also were sticking out threads, sidewall cuts, if it will survive sidewall cuts, then it torn off pieces of rubber after a while, so you can see cord
everyone who I know who have used conti before, all of them are on new tires this year
just do not listen to those who say that the conti is better than vittoria

MoPho
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Joined: Sun Jul 10, 2011 7:48 pm
Location: NorCal

by MoPho

I recently bought a new GP4000 that was defective, had a lump of rubber in it that I only discovered after banging my head dismounting and remounting several times thinking I didn't have it on right. That said, I've been through probably 20 of them over the years and never had any issues prior.





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Bordcla
Posts: 250
Joined: Wed Dec 20, 2017 3:42 pm

by Bordcla

Are you sure it's not a matter of the tire bead sitting too low or too far inside the rim in some spots? I had that issue with my Reynolds wheels and their deep center channel with sharp sides, where the tire bead got hooked and caused the tire to sit unevenly around the rim.

Ultimately had to inflate at much higher pressure, which caused the tire to pop into its correct position.

YMMV.

billspreston
Posts: 351
Joined: Tue Jun 30, 2009 7:40 pm
Location: CA

by billspreston

@Bordcla - these are being mounted on the latest ENVE 3.4 rims and, yes, with the tubless rims the bead fits very tight. I get loud popping noises as the bead seats up on the rim, but after around 60 psi the noises stop and I've assumed the tire is sitting straight. My wheelbuilder was the one who actually discovered the tire issue when I sent the wheels back thinking they were out of dish. His assessment was also that the tires were simply defective and to use a different tire. I'v also mounted the tires on different rims with the same strange fit.

Attermann
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Location: Denmark

by Attermann

why don't you just check around the bead that all has been popped out?

Bordcla
Posts: 250
Joined: Wed Dec 20, 2017 3:42 pm

by Bordcla

I only realized what the problem was by looking at the amount of textured sidewall showing all around. Take a look and if the sidewall is unequal around the circumference, that would be an indicator of the bead needing to pop into place there.

PrimO
Posts: 144
Joined: Thu Nov 20, 2014 8:49 pm

by PrimO

I havent come across that problem and I use the same tyres.

What i do when fitting a new tyre on a rim is inflate it to around 120psi first time to ensure it has seated properly all round and then delflate to desired pressure (75-80psi in my case)

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kode54
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by kode54

yes. i over inflate when first mounting a tire to make sure its seated correctly. and then let air out to my preferred pressure.

i've had a set of Conti tires not seat on a tubeless rim. i wasn't sure what the issue was so i put it on a regular rim and it seated straight. i then remounted onto the tubeless wheel, increased the pressure, bounced the tire on the floor and it turned out fine.
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