Schwalbe Ultremo blowing off rim

[Comedian]

Ok, an update. I've been periodically going and pumping the continental force up to 120psi on the rear durace c50. This is after removing the factory rim strip and putting cloth tape on. No BOOM at this point.

I'm going to re-fit the front tyre with rim tape, and I'm going to leave both of them for another week or so. If they are still on the rim I'll bite the bullet and fit them on the bike and take them for a little roll.

The problem with this insidious issue is that it's going to take some time to get the confidence back in the whole thing.

[bosvit]

The problem with this insidious issue is that it's going to take some time to get the confidence back in the whole thing.

Absolutely!

Just send them to me and you wont have to stress about it ever again!

[jasonc]

Just send them to me and you wont have to stress about it ever again!

I've got first dibs I believe

[winstonw]

Lot of people looking backwards in that photo ... If it doesn't bring me down I prefer to keep my eyes looking forward when I am two inches off someones else's wheel!.

This was the final sprint, so those towards the back were out of contention. I included the pic because everyone heard the "bang", and thought wt.

[winstonw]

The problem with this insidious issue is that it's going to take some time to get the confidence back in the whole thing.

At least it's been consistent.....getting death wobble, even once, is enough to steal confidence long term in your frame, wheels, self.

By changing the tape and tire type, that's two things changed simultaneously. Wouldn't it be more revealing to change one thing at a time....so tape and same tires as before?

[Comedian]

The problem with this insidious issue is that it's going to take some time to get the confidence back in the whole thing.

At least it's been consistent.....getting death wobble, even once, is enough to steal confidence long term in your frame, wheels, self.

By changing the tape and tire type, that's two things changed simultaneously. Wouldn't it be more revealing to change one thing at a time....so tape and same tires as before?

We did. We put the contis on the wheel with the old tape and it blew off! That was the oh no moment. So, we replaced the tape with the same tyre and it's still on.

[bosvit]

I guess it will be interesting to see how the Ultremo's go with the new rim tape if it all works out with the Conti's

[eeksll]

all this talk of stretching the bead makes me a little queasy. I know when I first got the gp4000s I couldn't een get the first bead on my dt-swiss wheels even with tyre levers. Now I can take them off and put them on the rims with my hands.

in terms of stretch, i eventually got them on by installing them on a R500 (which has a deeper center, hence easier to fit), pumping them up to 120, wait an hour or so, let them down and install on the dtswiss wheels, definite stretch in a very short period.

[Philipthelam]

The more I think about this issue, the more I am confident that the OP is stretching the tyres by over inflating them.

In my very limited knowledge, I'd think this was the cause as well.

lets see how the new tires go.

[ijpnic]

In my limited experience with the Ultremo Tyre, schwable have very varied quality between different manufacturing times. they are usually a very good Tyre but you will sometimes get a few that are duds and refuse to behave. I dont know if anyone else has noticed this but that's just my point of view, thats why i run conti's

[Comedian]

Ok. The c50 still has the conti on the rim.

However my c24 ultremo DD was down to the canvas so I had to do something. I took the Dd off, removed the blue factory rim tape, and replaced it with cloth.

I then grabbed one of the near new ultremo ZX that had blown off the c50. I fitted it using the usual procedure and pumped it to 140. It's still on the rim this morning. That's a good sign... but not conclusive. I may max it out and leave it for a few more hours. If its still up this afternoon ill drop it to 110 or so and ride it. Cross fingers.

If you don't hear from me again.. you'll know what happened.

[Nobody]

If you don't hear from me again.. you'll know what happened.

Leave a message with one of your friends to post if you don't make it. That way we'll know for sure.

[antipodean]

Why do you insist on pumping it to 140 psi? Like others have mentioned this is more than likely the cause of your problem.

[Comedian]

Why do you insist on pumping it to 140 psi? Like others have mentioned this is more than likely the cause of your problem.

It's kind of a check pressure test. The manufacturers of both the tyre and the rims specify a max pressure of 10 bar. I figure they have both got substantial margins in those figures. As you've seen above, the tyre manufacturers state that they are good for up to 290psi!

See... my theory is if it doesn't blow off at 145, then if I back it off to 120 ... it shouldn't blow off at that. If the past I've had them blow off at as little as 115.

As you can see by me typing this message, I survived my test ride at 120 today on a ZX (with about 150k). It was fitted to the DA C24 minus the factory blue rim tape (replaced with cloth). Cross fingers...

[bosvit]

Let's hope all your problems were caused by something as simple as rim tape.

[Comedian]

Let's hope all your problems were caused by something as simple as rim tape.

In a week or two ill feel more confident that we have a solution.

[Comedian]

This may not make for interesting television but I survived another schwalbe ride today without incident. Nice little stroll through the hills...

[bosvit]

Your a man on the edge Mr Amos

[Comedian]

Your a man on the edge Mr Amos

Thats just the way I roll.. Boom Boom... I mean.. oh never mind.

[winstonw]

Comedian, weren't you having blow offs on all three wheelsets?
I'd be interested to know if you have ever stored your wheels in your car or some other hot place that may have stretched the plastic type rim tape excessively.
Or maybe 140psi is unduly stretching the tape?!

[biker jk]

Comedian, weren't you having blow offs on all three wheelsets?
I'd be interested to know if you have ever stored your wheels in your car or some other hot place that may have stretched the plastic type rim tape excessively.
Or maybe 140psi is unduly stretching the tape?!

That's a good point since the Shimano rim tape is rated to 145psi. Each 10 deg celsius rise in temperature increases pressure by 1 psi. So if the temp rises 30 deg that's an extra 3 psi. From 140 psi you're getting close to the rim tape's limit.

[Comedian]

Comedian, weren't you having blow offs on all three wheelsets?
I'd be interested to know if you have ever stored your wheels in your car or some other hot place that may have stretched the plastic type rim tape excessively.
Or maybe 140psi is unduly stretching the tape?!

There are three wheelsets in play here. The C24 and Mavic's have only had maybe one or two blow offs. The durace c50 I was just unable to keep the bloody tyres on!

The bike may have been in a car occasionally but I can't think of a case where it has been. We have an external bike carrier and this is how I carry it although I ride everywhere so this is a very very occasional thing. So, being stored on the rack behind the car probably isn't greatly different to actually being ridden, or leant up against something at a cafe in the sun.

[bosvit]

Hey Comedian

I think you need a shirt with something on it like

"In my experience you are not experiencing what you think you are experiencing"

[Comedian]

Hey Comedian

I think you need a shirt with something on it like

"In my experience you are not experiencing what you think you are experiencing"

It's pretty funny - hey? You've got three very experienced riders who have never had a problem fitting tyres to wheels. Some new tyres from two reputable brands. Some top shelf wheels from a prominent Japanese manufacturer. And no one can make them work together.

So we've got people saying...

- You're fitting them wrong.
- You're pumping them up too much - even if it is below the max pressure.
- You're generally incompetent.
- You're using them to ride a bike on.
- You're leaving them in your car.
- The rims are cracked.
- The spokes are too tight.
- Your gauge is inaccurate.
- You're not using nitrogen.
- You're stretching them putting them on.
- You should stop using them as props in bondage roll play games.

Did I miss anything there? I'm sure there is a little bit of truth in all of those points. Many of them may be contributors. I'm not prepared to call it finally yet, but it's looking like it was actually just the rim tape!

[Nobody]

- You're not using nitrogen.

Strange comment since the air is 78% nitrogen.

Did I miss anything there?

Yes.

- Rims not able to handle the pressure.

I'm sure I read that at least once.