hell of a puncture — rim damage — need advise pls

absorption

So I hit a big 'ol screw that went straight through tyre + tube, embedded so the point of the screw ended up putting a little hole in the rim (on the flat internal part of the rim where the tube sits against it). Hole is probably 1mm in diameter, not very big.

Is it OK leaving alone or is any damage like this going create a big risk?

thanks

ugo.santalucia

Just sand it to avoid it piercing the next tube, cover it with tape and forget about it

buckmulligan

Pics would be helpful. How close to the nearest spoke hole is it?

Unless there's any obvious red flags (such as cracks propagating from the hole) I'd be inclined to say it's fine. After all, somewhere else on the rim there's a massive hole drilled all the way through it for the valve stem; those things are pretty strong.

crankycrank

Drill it out with the smallest drill bit that will be just big enough to create a nice round hole with a smooth edge. This will reduce the likelihood of a crack developing.

absorption

Awesome thanks everyone. The hole is pretty isolated and on these Mavic wheels that inside part of the rim against the innertube is separated from where the spokes come in so it's all one piece if that makes sense. I'll have a look at that hole and make sure all is smooth around there, I think it is a pretty clean hole as the screw literally punctured that metal.

Appreciate the advise!

wishitwasallflat

There is now a hole, created by an unnatural (i.e. one the rim was not designed to experience in normal use) force, in a rim, where there was never meant to be a hole - I would replace it. The human body is too fragile to take chances like this. Yes it could be fine, but maybe it wont and if it fails and you fall you wont end up in any less pain, or experience less trauma, because people thought it wouldnt.

cycleclinic

replacing the rim is the safe thing to do but rims even with cracks dont just fold. Seen lots of a cracked rims in the shop, the wheel goes out of true it is brought in can you fix it - I say no its cracked look. They go oh. The point being they walked into the shop not stretchered in. You'll know if the rim cracks as the wheel will go out of true continue riding it and it might fold but you get a fair bit of warning. I have seen a rim cracked most of the way around the rim from spoke hole to spoke hole and that wheel did not fold.

The Rookie

Depends on the rim, most are a continuous extrusion, so the screw hole is less of a strength reduction than the valve or spoke holes.

With the other advice, clean it up, patch/replace the rim tape and carry on riding.

wishitwasallflat

Well reassuring to read its unlikely/wont fail catestrophically if it did fail - but - personally I would still replace it. I suppose though I'm in the fortunate position that the cost involved would be no big deal so its easy for me to choose that option.

svetty

wishitwasallflat wrote:

Well reassuring to read its unlikely/wont fail catestrophically if it did fail - but - personally I would still replace it. I suppose though I'm in the fortunate position that the cost involved would be no big deal so its easy for me to choose that option.

Any wheel might fail after hitting a pothole - as could a fork, a steerer tube, etc etc. Best replace the whole bike each time as you can never be certain that it is safe afterwards.... :roll: :roll:

wishitwasallflat

Svetty wrote:

wishitwasallflat wrote:

Well reassuring to read its unlikely/wont fail catestrophically if it did fail - but - personally I would still replace it. I suppose though I'm in the fortunate position that the cost involved would be no big deal so its easy for me to choose that option.

Any wheel might fail after hitting a pothole - as could a fork, a steerer tube, etc etc. Best replace the whole bike each time as you can never be certain that it is safe afterwards.... but if you see a f@#$ing hole in some part of the bike afterwards thats a good clue that something may be amiss:roll: :roll:

FTFY!

PS This conversation has nothing to do with potholes by the way. Its the possible consequences of

big 'ol screws

poking holes in rims that those who are paying attention are discussing here.

wishitwasallflat

The Rookie wrote:

Depends on the rim, most are a continuous extrusion, so the screw hole is less of a strength reduction than the valve or spoke holes.

With the other advice, clean it up, patch/replace the rim tape and carry on riding.

Mmm... no matter the construction method though the rim was engineered to have valve and spoke holes, that is not the case with holes caused by screws. That's partly why I question why some are so confident that it will be fine in this specific case. At least cycleclinic wrote about personal experience of dealing with such holes so that was helpful. I have to also note that no one who said its safe has seen the hole in question, nor appears to have considered if this is a front or rear wheel - before advising the op its safe. I fully admit to being cautious when it comes to bike safety but these factors do make me doubt the depth of analysis that underpins the advice that this will be/is safe.

slowbike

wishitwasallflat wrote:

The Rookie wrote:

Depends on the rim, most are a continuous extrusion, so the screw hole is less of a strength reduction than the valve or spoke holes.

With the other advice, clean it up, patch/replace the rim tape and carry on riding.

Mmm... no matter the construction method though the rim was engineered to have valve and spoke holes, that is not the case with holes caused by screws. That's partly why I question why some are so confident that it will be fine in this specific case. At least cycleclinic wrote about personal experience of dealing with such holes so that was helpful. I have to also note that no one who said its safe has seen the hole in question, nor appears to have considered if this is a front or rear wheel - before advising the op its safe. I fully admit to being cautious when it comes to bike safety but these factors do make me doubt the depth of analysis that underpins the advice that this will be/is safe.

it's a ~1mm hole - that's smaller than those drilled in for the spokes and much smaller than the hole drilled in for the valve.
Other than it's proximity to a spoke hole and ensuring there are no cracks forming - it's highly unlikely to catastophically fail in the next few miles.

Suggestions to clean it up - tape if required and just keep an eye on it are adequate - the probability of something else going wrong is far higher than this hole being an issue.

wishitwasallflat

Well all can say to that is I admire your ability to make such a confident diagnosis and risk assessment without either seeing the hole or considering if its a front or rear wheel. I suppose the bottom line is how one feels about risk.

The Rookie

If you were that risk adverse you wouldn't be riding a bike on the roads at all......the risk of getting hit by a car is going to massively outweigh the risk of that failing catastrophically.

As above the rim is designed to cope with holes, so a 1mm hole is going to create less risk than the valve or spoke holes!

wishitwasallflat

I am that risk averse and I do ride on roads. I do all I can to avoid the risk of being hit by cars and also replace damaged items when I see they are damaged. As I said I could afford to and so would, replace a rim if a screw poked a hole in it. I also wouldnt give advice on damage I hadnt seen over the internet - but - I have no problem if people do that I am just presenting another way to view this question and an alternative conclusion for the op's consideration.

ugo.santalucia

wishitwasallflat wrote:

Mmm... no matter the construction method though the rim was engineered to have valve and spoke holes, that is not the case with holes caused by screws. That's partly why I question why some are so confident that it will be fine in this specific case. At least cycleclinic wrote about personal experience of dealing with such holes so that was helpful. I have to also note that no one who said its safe has seen the hole in question, nor appears to have considered if this is a front or rear wheel - before advising the op its safe. I fully admit to being cautious when it comes to bike safety but these factors do make me doubt the depth of analysis that underpins the advice that this will be/is safe.

It's not a stressed part of the rim... it's there to support the inner tube, but otherwise you could do without it...

darkhairedlord

fill the hole with araldite, dress flat before it cures. job done.

wishitwasallflat

ugo.santalucia wrote:

wishitwasallflat wrote:

Mmm... no matter the construction method though the rim was engineered to have valve and spoke holes, that is not the case with holes caused by screws. That's partly why I question why some are so confident that it will be fine in this specific case. At least cycleclinic wrote about personal experience of dealing with such holes so that was helpful. I have to also note that no one who said its safe has seen the hole in question, nor appears to have considered if this is a front or rear wheel - before advising the op its safe. I fully admit to being cautious when it comes to bike safety but these factors do make me doubt the depth of analysis that underpins the advice that this will be/is safe.

It's not a stressed part of the rim... it's there to support the inner tube, but otherwise you could do without it...

Wow, must admit because its made of metal and it spans and joins the two sides of the rim I had assumed it would have contributed to strength in some way. At least by helping to prevent the sides spreading apart. Well you learn something every day.

Wonder why some bright spark hasnt made a rim with some sort of lighter mesh or something in there instead like kevlar maybe? Must be a few grams to be saved by not using metal,

The Rookie

Look at fat wheels.....

slowbike

wishitwasallflat wrote:

ugo.santalucia wrote:

Wow, must admit because its made of metal and it spans and joins the two sides of the rim I had assumed it would have contributed to strength in some way. At least by helping to prevent the sides spreading apart. Well you learn something every day.

Wonder why some bright spark hasnt made a rim with some sort of lighter mesh or something in there instead like kevlar maybe? Must be a few grams to be saved by not using metal,

The rim is >2000mm in circumference - 1mm out of that isn't going to make any difference - providing there are no cracks.
As for making a diagnosis over the internet - it's worth how much the OP is paying for it - ie nothing - it's still up to the OP to consider the advice given.
As for why they don't use a mesh or other material - there's a lot of pressure against it from the inner tube - so (at a guess) any other method wouldn't survive that - plus the weight gain from having to fasten the replacement material would offset the amount saved.

ugo.santalucia

A clincher tyre will try to rip the rim apart longitudinally, however I have never seen reports of a rim where a crack developed longitudinally on the rim bed. The do on the nipple bed, but that is a highly stressed area, when you have a force of 100 Newton or more localised over a few mm area.

Bear in mind a rim will fail at the braking track when the latter is about 0.7-0.9 mm, which is a lot thicker than the rim bed... so that tells you where the stress is

wishitwasallflat

ugo.santalucia wrote:

A clincher tyre will try to rip the rim apart longitudinally, however I have never seen reports of a rim where a crack developed longitudinally on the rim bed. The do on the nipple bed, but that is a highly stressed area, when you have a force of 100 Newton or more localised over a few mm area.

Bear in mind a rim will fail at the braking track when the latter is about 0.7-0.9 mm, which is a lot thicker than the rim bed... so that tells you where the stress is

Thanks ugo that makes sense. I suppose my concern boils down to wondering if that lateral outward force on the rim walls, that causes brake tracks to split, be as well foccused on the brake track only, if that bit that sits below the inner tube was compromised in any way?

FWIW I freely confess to being a coward and I would replace the rim anyway just in case! Over the top ... maybe ... but for me better than potential alteratives if, for example, that rim was a front and I ignored it, and a crack propegated at some later date and the wheel had problems - not neccesarily catestrophic failure - but, having had one way scary front wheel puncture, I dont ever want any risk of front wheel problems, of any kind, ever again.

Bobbinogs

I think it is fair to say that we all have our own view of what risks are acceptable and what are not. Cost/affordability comes into it to some degree but not exclusively and what is someone's acceptable risk does not mean anyone else should or should not accept it. Good health and safety is about assessing risk and determining the controls (if any) needed, not treating everything as an unacceptable risk. In this case, given the OP's description of the issue then I would have no qualms about riding with that rim but might check it periodically as part of the usual maintenance routine.

Wishitwasallflat, I would try and move on from your bad experience. The problem is that, whether you like it or not, every time you ride you do risk a front wheel incident in the same way you run the risk of any kind of incident when doing anything (there are stories of bad injuries from falling off when turbo training, let alone getting out on the road).

wishitwasallflat

Bobbinogs wrote:

I think it is fair to say that we all have our own view of what risks are acceptable and what are not. Cost/affordability comes into it to some degree but not exclusively and what is someone's acceptable risk does not mean anyone else should or should not accept it. Good health and safety is about assessing risk and determining the controls (if any) needed, not treating everything as an unacceptable risk. In this case, given the OP's description of the issue then I would have no qualms about riding with that rim but might check it periodically as part of the usual maintenance routine.

Wishitwasallflat, I would try and move on from your bad experience. The problem is that, whether you like it or not, every time you ride you do risk a front wheel incident in the same way you run the risk of any kind of incident when doing anything (there are stories of bad injuries from falling off when turbo training, let alone getting out on the road).

Good advice - working on taking it but its been a bad year with a car ramming me on a roundabout in April so its a process getting back to normal and I freely admit Ive probably replaced a fair few things that still had mileage in them.

absorption

Thanks everyone for the comments and discussion it's been interesting to keep an eye on and appreciate the dialogue. I can confirm it is a rear wheel, Mavic Ksyrium Elite, I can try and supply a picture for interest.

I'm probably going to get the rim replaced just for peace of mind. I sort of figured any breach would mean a replacement was in order but appreciate that might not always be the case.

ugo.santalucia

absorption wrote:

I'm probably going to get the rim replaced just for peace of mind.

It would be interesting to see this happening...
If it ever was to happen, then you are gambling on the shop doing a half decent job, which is probably a much bigger risk than just leaving the wheel alone.

I have built a fair few hundred wheels in my days (gotta love this expression, makes me look very ancient)... Mavic spares are hard to come by and their wheels are not the easiest to rebuild to the same standard as the factory... but good luck with that...

slowbike

hmm ... I have a Mavic rear wheel sat in the shed doing nothing because the hub broke - a spoke pulled through! I have no use for the rim/spokes and was thinking of disposing...

ugo.santalucia

Slowbike wrote:

hmm ... I have a Mavic rear wheel sat in the shed doing nothing because the hub broke - a spoke pulled through! I have no use for the rim/spokes and was thinking of disposing...

Well, over the years they have changed the rim-spoke interface... what is referred to as the FORE cup. They need to be of the same generation. Then you have to find someone willing to rebuild the wheel to a decent standard.
Mavic wheels are the classic machine built wheels which are very hard to rebuild by hand... you can, but it is difficult to achieve the same standard as the original build. Basically the spokes are supposed to be inserted and tensioned all at the same time, rather than one by one. Having only 20 spokes, you don't have much tolerance for error.

It's a case where peace of mind is misplaced. The original rim with a hole is a much more reliable wheel than any hand-rebuild attempt will ever be... let alone having to spend money to achieve that...

slowbike

Ah well - I'll see if I can get some pictures over the break and get it up in the "For Sale" section ... never know - the hub may be of some use to someone - or just replacement spokes... eitherway, it's not doing me any good where it is.

absorption

ugo.santalucia wrote:

absorption wrote:

I'm probably going to get the rim replaced just for peace of mind.

It would be interesting to see this happening...
If it ever was to happen, then you are gambling on the shop doing a half decent job, which is probably a much bigger risk than just leaving the wheel alone.

I have built a fair few hundred wheels in my days (gotta love this expression, makes me look very ancient)... Mavic spares are hard to come by and their wheels are not the easiest to rebuild to the same standard as the factory... but good luck with that...

yes so interestingly enough my shop mentioned that Mavic will only do that type of repair at factory, they won't supply rim spares so it'll be sent back so looks like you're right!