tsmith41094

Had a SCREW go straight through my tire/tube and into my rim during my ride today.



The hole left by the nail almost looks like a smaller version of the one for the valve stem (although it doesn't go all the way through to the other side).



It seems like it is pretty clean (no signs of other cracking, etc.) but I'm not sure if I should be worried about the integrity of the rim. What do you guys think?

Danhedonia

I think this is God's way of telling you to go tubeless.

10 Wheels

Thanks for the Good Pics
Hummm. That is a Screw,
Put some tape over the hole and ride.

Maelochs

First off, that's a screw..

Whether or not the rim was temporarily or permanently screwed, I cannot say. I would ride it and check for cracks after riding.

tsmith41094

Thank you to all who identified my gross mischaracterization of fastening agents. I tried to salvage what I could in the description.

BobbyG

I agree with Maelochs , ride, then check for cracks.

Sy Reene

Second off, that's a pretty shiny carbon rim.

Cyclist0108

Although it is a screw, it was almost certainly driven into your rim as if it were a nail. It looks clean on this side, as if it were carefully drilled, but the exit wound is what you need to worry about. Is is all splintered on the other side, with frayed carbon fibers, etc? I personally would not trust that wheel unless inspected by an expert (as opposed to pedants on the internet who might not even have any direct experience with carbon fiber rims, let alone pierced carbon fiber rims).

Maybe take a small piece of wire, bend it at 90°, insert it into the hole, and try to feel for splintered fibers on the inside.

SClaraPokeman

A few years ago a Canadian in these forums was asking about putting a patch on a sidewall of a new tire that was cut. I said maybe it was repairable but how is it worth it to even take a chance on the integrity of the repair and have to seek medical treatment in a worst case. He joked in reply that in America he would definitely fear that but hey, he's in Canada and a ER trip doesn't potentially put him behind the financial 8-Ball (plus bicycle stuff in Canada is more expense--in part to help pay for things like nationalized health care).

Seriously it does look like a drilled hole and maybe it won't spread but I tend to error on the side of caution on things wheel related. Also, I'm not even sure it would be that easy to get a local to you definitive expert opinion. There is a master mechanic not far from me in Seattle and his website states that he will not give opinions about the safety of carbon parts that may have been compromised. Plus what you gonna do, remove the tire after every ride to inspect the hole? I guess if I was determined, I could call the manufacturer and see about sending it to them. Might be more expense and hassle than it's worth though.

I have a pair of Reynolds carbon wheels, I think the first two years of usage were under all circumstances guarantee, but you'd have to buy a warranty for a lifetime coverage--which I didn't do.

Koyote

I would not, under any circumstances, ever again ride on that rim.

My understanding is that, in cf rims, valve and spoke holes are surrounded by extra material -- i.e., the rim is designed around those holes so that they won't lead to failure. The hole in your rim is an intruder.

Ask yourself this: on a typical ride, what are potential consequences of a sudden and catastrophic failure of this wheel? On a typical ride, I hit 30+ mph on several stretches, and 40+ mph on at least one stretch. No way would I ride on a compromised rim. But then, I value my noggin and my teeth as being worth more than a few hundred bucks.

10 Wheels

He rode it for another 9,500 miles

Cyclist0108

Yeah, but (a) it is a nail, (b) it did not penetrate the rim, and (c) the rim in aluminium.

10 Wheels

Another Screw.

Cyclist0108

Looks like a dry-wall nail, but the identify of the fastener is, as the OP points out, a pointless distraction.

Litespud

right on (b) and (c), but that’s definitely a screw - a 3-3.5” deck screw
wrt the OP, the hole may look nice and clean, but it was caused by a screw being driven forcefully through the carbon weave, so god only knows what the “exit hole” looks like. I imagine the concern is that, with the CF weave disrupted, the outward pressure from the inflated tire may cause the weave to rip or essentially “unzip” around the circumference of the rim. Question is, would it happen gradually (and if this was a rim-braked rim, you’d likely notice it in brake pulsating) or catastrophically? There’s no way of predicting, and I suspect that any serious attempt to visualize what the exit hole looked like* would exceed the cost of simply offering it up and replacing the rim.
*and even then, any conclusions re effect on rim integrity would be mere speculation

Ghazmh

I would retire the rim without riding a single mile on that!! If it’s a good hub have the wheel rebuilt otherwise replace the entire wheel.

woodcraft

1. That's pretty much the definition of a hole. If you mean that the rim material is thicker at each spoke hole, I challenge you to find a single example where that is true.
2. In the OP's case, the hole is in the same place where there are normally 20 or more similar but larger holes
3. With that level of anxiety, maybe consider a maximum speed of 26mph.

Koyote

1. Challenge accepted! It took me about 30 seconds of googling to find not one, but two examples: Light Bicycle will add small drain holes to their carbon fiber rims for riders who are worried about water getting inside them… But if you scroll down on this page, you will see that they add them at the buyer’s request and then provide reinforcement around each hole. On thispage, Enve describes how they actually mould the carbon fiber around each hole, rather than just drilling through the rim, because it results in greater strength.
2. Yes, there are many holes in a bicycle wheel rim. But the new hole is one for which the rim was not designed. Would you ride a carbon fiber frame that had an extra hole created by a random accident? Perhaps you would; I would not.
3. Don’t confuse anxiety with prudence. I have no anxiety about going fast on a bike; in fact, my top recorded speed —on an incredibly steep descent in a Colorado road race – – was 75+ miles per hour. But I would not ride such a compromised rim around the block.

We all have different levels of risk aversion, and different budget constraints. I have plenty of money and I value my safety. I would simply buy a new rim.

At the end of the day, the original poster can decide what to do for himself. He was asking for input, and I provided mine.

vane171

It is on the rear wheel, so in case of failure, it is more forgiving. BTW it baffling how one can make such a puncture with a screw at right angle into the tire. Normally such long screws lay flat on ground and it is rare that you would make a puncture on them. You rode through some industrial area or a construction site where a carpenter lost a bunch of screws from the back of his truck, or what.

And as was said, this area is where aluminum rims traditionally used to have big holes at each spoke through which you inserted nipples (maybe that was in old times and is not practiced anymore... BTW how are nipples inserted on a rim like this one that has no access holes under the tube/tire?), so quite generally this area is not a critical part of the rim. Of course, carbon fibers are a different material susceptible to unraveling but still. I would smear epoxy glue on the hole edges to maybe stop that.

I can see though why some people would not ride on such a rim anymore. I'd consider relegating the wheel to use on a trainer. I guess you need to assess how you ride, where you ride etc.

Litespud

I had an almost identical encounter with a similar fastener (drywall screw) last year. Screw went straight in through the front tire and into the rim bed - difference was it was an alloy rim, and the screw punched a ~1-2mm hole before it stopped. No idea how a screw presumably lying flat on the road ended up going straight into the wheel, but there it is. I replaced the tube, booted the tire and rode home, but the hole in the tire was sufficient to retire the tire after that. The hole in the rim bed was inconsequential - I replaced a stretch of rim tape to cover it and moved on

woodcraft

Kudos on the searching, 'tho I don't see where Envy claims to add material at each hole, and Light's "reinforced" drain holes could be more marketing copy than reality.

I react to what I consider unwarranted concern over "sudden and catastrophic failure" of CF that gets repeated and passed around like a virus.

IMO, the odds of the OP's rim damage leading to injury from sudden and catastrophic failure are about the same as from going for a run with a hole in your sock.

This is based on 50+ years of hands-on work with materials. I would advise the poster in another thread against drilling his alloy handlebars, 'tho...

Koyote

I didn't expect you to admit that you were wrong on #1...After all, this is the internet. No one ever admits to being wrong about anything, even when given evidence.

As for the rest: it's your opinion, so not really debatable. Mine differs. Though we are in total agreement about that handlebar drilling.

PS: I've had "50+ years of hands-on work with materials," too. Why, just the other day I was kneading some bread dough - that's a material, I believe, and probably about as relevant as your experience is to cf bike rims. (In other words: if you're going to use the "appeal to authority" fallacy, you should try to be more convincing.)

bbbean 

Sorry to say, but I wouldn't ride on that wheel until and unless it was repaired by someone who knew what they were doing.

vane171

Aargh, just put some patch over the hole after fixing the hole edges with epoxy glue I suggested (the patch is so the tube wouldn't press into the hole and blow up) and make a mark on the nearest spoke or on the rim to be able to tell where the hole was and test it by running your hand over the place after the first few rides, then at some bigger maintenance occasion, make it a point to remove the tire for inspection and if you won't see any fraying near the hole, just ride it with a fair piece of mind.

79pmooney

I would have zero issues using that rim after doing a carbon fiber and epoxy resin repair over that hole. (My concern would be the rim spreading and spitting from tire pressure. I would concentrate on CF fibers running across the rim at the hole and an inch or two up and down the rim. (Maybe laying cloth in on the diagonal.) For the rim as a beam, that hole is within the web and making very little difference. (They cut large holes in bridge beams.) How bad it looks on the other side doesn't matter much as a beam.

Now, I would make it a point of doing very clean fiberglass work. (Not hard - I used to build fiberglass boats, have done many repairs and that is a place with easy access and good visibility.) Biggest issue would be getting a good bond to the existing surface,