Will really tight tires untrue carbon clinchers?

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by TheBugMan

Will really tight tires untrue carbon clinchers?

A year ago I got a used pair of 2006 Reynolds Stratus DV46C wheels that had Continental Grand Prix 3000 tires mounted. About three months ago I put some Michelin Pro 3 Race 700x23 clinchers on. I started to notice some noise coming from a few spokes soon after mounting the new tires on the front. I thought this was from normal wear and tear since I'm not gentle with the bike, plus it has been over a yr since I trued the wheels.
I PMed some folks for help and get all the stuff needed to true the wheels(big thanks to Legs 11 for answering my nob questions) and began last night.
This is where things get weird for me...
Before I took the Pro Race 3s off there was two loose spokes that rattled to the touch before un-mounting the tire. I took the tire off and rim tape but could not find the loose spokes! I was like "WTF?" I had to check them all several times.

I will add these observations...
1) The Pro Race 3s where extremely hard to mount the first time, I broke two tire irons getting them on.
2) The old rim tape I removed was thick compared to the new tape I used last night before re-mounting the tires again, maybe 2/3 times thicker.
3) I'm not sure if it was because I used some liquid soap or because of the thinner rim tape to re-mount the tires but the tires mounted much easier(didn't break any tire irons this time). Or maybe the tires were a little bit stretched out by now?

All I know now is that the tire is true again with no loose spokes. Why?
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by Irish

(in relation to observation No 3)Always found that using thicker rim tapes made mounting/dismounting tyres much harder, due to the fact it increases the diameter of the bed of the rim and therefore reduces the amount of "play" around the rim when fitting the tyre.As an inflated tyre compresses a rim i'm sure it would have a small effect on spoke tension if the rim is "soft"(would have thought that 46mm deep rims were fairly rigid by design).

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by mattr

a badly calibrated (ok, not calibrated at all) track pump did this to a friends Kysiriums.

110psi indicated gave about half a dozen noticeably loose spokes. As soon as the tyre was deflated, problem gone.

When we reinflated and checked against my (admittedly not calibrated, but 20 years flawless service) track pump it turned out that the indicated 110 psi was more like 150-160psi and pretty close to blowing the tyre off the rim.......... checking with the shops digital gauge showed that my pump was about 10psi off.

And no, if you can get a tyre on it must be loose in the rim bed, or at least loose enough to not be putting any noticeable pressure on the rim bed.

Stick 110psi in the tyre and you have *about* 60 sq in (from my quick calc) of rim being pushed in, about 7000lbs in total round the diameter.

Any slightly loose spokes or weaker spots in the rim will be highlighted by this. Carbon rims, due to the way they are laid up (rather than extruded) are likely to be *very very slightly* more likely to suffer from this.

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