And it went thru the tire, tube, rim tape, and center web of the rim!!

DAMM!T Looks like a new Race-Lite rim for me.

Has anyone else ever had this happen? How can a nail be so perfectly aligned? I couldn't have driven it through my wheel straighter with a hammer.

Man....

And it went thru the tire, tube, rim tape, and center web of the rim!!

DAMM!T Looks like a new Race-Lite rim for me.

Has anyone else ever had this happen? How can a nail be so perfectly aligned? I couldn't have driven it through my wheel straighter with a hammer.

Man....

Yes, I had a nail go through tire, tube, rim strip, and tire bed of the rim, and halfway through the rim's spoke bed once. Stranger still, it was a front wheel. This type of occurance is more common with the rear wheel, because a nail or other sharp object laying on the road can get flipped up by front wheel, and then puncture the rear tire when it is in a more vertical position.

The tube can be patched, and the tire may or may not be salvagable depending on the size of the hole, but why replace the rim? A little hole like this won't really weaken the rim, since the rim already has plenty of much larger holes in it already (like the holes the spokes and tube stem go through). When I had a nail go through tire and rim, I just pulled the nail out, patched the tube and the rim strip, and kept going.

I guess that I'm looking at the worst case....

I'm going to take the rim strip off tonite, and look at the rim bed. The position of the hole lets me think that if I drill it out to stop any edge cracks, then I wont have to worry about it.

The hole is in between the close spokes in the paired setup. In engineer speak, I think that the hole is close enough to the neutral axis of bending, that the stresses around it will be fairly low. Its just a wait and see question. I guess its "How much damage was done" type question.

Ill post some pics.... Maybe Kerry will pipe up and let me know what he thinks.

Kerry, if you're listening, I think the biggest problem is stopping cracks from propogating from the "rupture" sight caused by the nail. What do you think? The more I think about it, the less I am worried about the stress in the rim bed.

B

I guess that I'm looking at the worst case....

I'm going to take the rim strip off tonite, and look at the rim bed. The position of the hole lets me think that if I drill it out to stop any edge cracks, then I wont have to worry about it.

The hole is in between the close spokes in the paired setup. In engineer speak, I think that the hole is close enough to the neutral axis of bending, that the stresses around it will be fairly low. Its just a wait and see question. I guess its "How much damage was done" type question.

Ill post some pics.... Maybe Kerry will pipe up and let me know what he thinks.

Kerry, if you're listening, I think the biggest problem is stopping cracks from propogating from the "rupture" sight caused by the nail. What do you think? The more I think about it, the less I am worried about the stress in the rim bed.

B

It is unlikely that a crack will propogate from a small hole in the tire bed. As pointed out before, there are already plenty of bigger holes in the tire bed, and cracks don't propogate from those. And there is a good reason that they don't. Metal fatigue only occurs under tension stresses (not compression stresses) and the majority of the rim (including the rim bed) is in net compression. On a typical 32 spoke wheel, the inward tension from the spokes puts the rim under about 1000 pounds of circumferential compression.

The only areas on the rim where there is significant tension stresses are near the spoke holes(**), where the static spoke tension causes the spokes to pull outward from the rim. This is why fatigue cracks only form at, or immediately adjacent to, the spoke holes (or at the eyelets that hold the spoke nipples). Consider: The hole in the spoke bed for the tube stem is even larger than the spoke holes, and yet rims never crack around the stem hole.

** The other place that there is any major tension stress is on the inside surfaces of the sidewalls on clincher rims, where the pneumatic pressure creates a bending stress on the sidewall. Fatigue generally only becomes an issue when the sidewalls have been worn too thin, increase the concentration of bending stress.

In any case, the tire bed doesn't see any significant tension, so it isn't prone to fatigue - even if there is a nail hole through it.

If the hole is between the two close holes, you could have a problem since there won't be enough material between a new hole and the spoke hole and soon enough a crack is bound to develop...

I've seen "plenty" of rims over the years with essentially this exact same injury. Highly unlikely to cause a problem. There's probably not even any reason to drill it out. Listen to Mark.

dude... that sounds awesome. post a pic. is it really that straight?

btw- sorry for your misfortune. :(