Riding flat tyre. Still safe?

vodafone_au
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Riding flat tyre. Still safe?

Postby vodafone_au » Mon Jan 29, 2018 5:10 pm

Hi, I got my front wheel punctured recently and I continue rode my bike 7km-ish albeit with some extra caution.

My question is, how do I know if my wheel (aluminium), tyre and tube are still safe to use. Also, should I better get a new tube (and tyre?) instead of using the puncture patch?

At present, I can't find anything suspicious. However, I'm a bit cautious since I did ride a bike for a while after the puncture (even at a slower speed) and I'm not sure whether there was any impact on my wheel (or tyre). In fact, I remember that my rim was hit by the ground at least 2-3 times during the flat-tyre riding.

The size of puncture could be small as I thought nothing was wrong when I re-inflated the wheel at home and pressed the bike and tyre few times. However, it eventually became flat again when I checked it again after few hours.

Thanks in advance for your kind advice!
Last edited by vodafone_au on Mon Jan 29, 2018 5:35 pm, edited 1 time in total.

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find_bruce
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Re: Riding flat tyre

Postby find_bruce » Mon Jan 29, 2018 5:32 pm

I would be doing a careful visual inspection - take the tyre off the rim & carefully go around the rim (start from the valve hole so you know when to stop) looking for flat spots, dents & deviations of the bead.

Same with the tyre & tube - look for cracks & wear.

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Re: Riding flat tyre. Still safe?

Postby Duck! » Mon Jan 29, 2018 9:43 pm

The tube may have suffered additional pinch-punctures from riding while deflated. Inflate and thoroughly inspect for escaping air. Patch it if the hole/s are small, discard if there are big or numerous holes. The tyre will probably be OK, but again thoroughly inspect for anything that may have caused the initial puncture. If the rim hit bumps of any note, check for flat spots and dents in the sidewalls.
I had a thought, but it got run over as it crossed my mind.

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Re: Riding flat tyre. Still safe?

Postby Kronos » Tue Jan 30, 2018 12:28 am

You haven't really done yourself any favors, in riding 7km. You may have put the wheel out of round permanently and destroyed the tyre/tube. Riding like this can put the rim through the canvas and rubber of the tyre. You can also end up with metal scraping on pavement/bitumen. If this happens next time and you don't have a spare tube and a patch kit... phone a friend, or just walk. There's no sin in doing the walk of shame to your local bike store. Most of us have been in that position at some point in our lives.

I most definitely don't mean any disrespect, but next time Don't let your ego get in the way, it's not worth the cost of a new wheel.

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gorilla monsoon
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Re: Riding flat tyre. Still safe?

Postby gorilla monsoon » Tue Jan 30, 2018 10:37 am

I just want to know how you ride 7km on a flat tyre.
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march83
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Re: Riding flat tyre. Still safe?

Postby march83 » Tue Jan 30, 2018 10:42 am

Yeah, that's terminal. You've done sufficient damage to the tyre's threads that it can't be trusted. Bin it and move on. Chalk it up to the price of staying safe.

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Re: Riding flat tyre. Still safe?

Postby human909 » Tue Jan 30, 2018 11:38 am

Duck! wrote:The tube may have suffered additional pinch-punctures from riding while deflated. Inflate and thoroughly inspect for escaping air. Patch it if the hole/s are small, discard if there are big or numerous holes. The tyre will probably be OK, but again thoroughly inspect for anything that may have caused the initial puncture. If the rim hit bumps of any note, check for flat spots and dents in the sidewalls.
Agreed. In my experience everything should be A-OK with the tyre. If you are careful then you can avoid denting the rim. No surprises if there is further damage to the tube, but by the sound of it you got away with it even with the tube.

As far as the many wowser comments. No really. When did people start thinking bicycle components were made of tissue paper.
Kronos wrote:You may have put the wheel out of round permanently
How do you figure that? The roundness of a wheel isn't particularly affected by this scenario. If badly treated then localised rim dents are definitely a risk, but out of roundness is a different cause and issue. If you are putting those forces into your rim with a flat I dare say you would be flying through the air as welll.
gorilla monsoon wrote:I just want to know how you ride 7km on a flat tyre.
Keep your weight back and ride slowly. Not biggy. Not fun though... More fun rolling along at 10-15kph than walking a bike...
march83 wrote:Yeah, that's terminal. You've done sufficient damage to the tyre's threads that it can't be trusted. Bin it and move on. Chalk it up to the price of staying safe.
How have you made that assessment? Treads are highly flexible so aren't easily damaged by flexing. (HINT: The clue is in the name.)
Last edited by human909 on Tue Jan 30, 2018 11:43 am, edited 1 time in total.

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Re: Riding flat tyre. Still safe?

Postby A_P » Tue Jan 30, 2018 11:42 am

gorilla monsoon wrote:I just want to know how you ride 7km on a flat tyre.
me too... i have limped out of the forest with a rear flat on the MTB, but front flat, thats walkin .

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Re: Riding flat tyre. Still safe?

Postby human909 » Tue Jan 30, 2018 11:47 am

A_P wrote:
gorilla monsoon wrote:I just want to know how you ride 7km on a flat tyre.
me too... i have limped out of the forest with a rear flat on the MTB, but front flat, thats walkin .
Depends on how straight you are riding. A front has far less weight on it, particularly if you sit/stand up to lighten up the front. Sure your ability to steer is poor but you're limping along so all good. I suppose on a MTB with chunky tires your could probably limp fairly quickly with a flat rear a flat front in bumpy terrain does sound yucky.

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Re: Riding flat tyre. Still safe?

Postby P!N20 » Tue Jan 30, 2018 11:47 am

gorilla monsoon wrote:I just want to know how you ride 7km on a flat tyre.
Wheelies

Kronos
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Re: Riding flat tyre. Still safe?

Postby Kronos » Tue Jan 30, 2018 1:06 pm

human909 wrote:
Kronos wrote:You may have put the wheel out of round permanently
How do you figure that? The roundness of a wheel isn't particularly affected by this scenario. If badly treated then localised rim dents are definitely a risk, but out of roundness is a different cause and issue. If you are putting those forces into your rim with a flat I dare say you would be flying through the air as welll.
Eventually if you keep riding on a rim like that you have a good possibility of wearing a nice little flat spot in your round rim making it entirely unusable forever. It's not really rocket science... Riding on concrete pavement/bitumen on alloy wheels is the equivalent of riding on a piece of sand paper. I don't need to figure the results I've seen them before. Eventually you're gonna wear straight through the tyre and be riding metal on concrete/bitumen. You wouldn't drive a car on a flat tyre, why is your bike any different? The only exception in this case is that there are now run flat tyres for cars, that's not the point other than to say the equivalent doesn't really exist for bikes.

Just walk or phone a friend.
Last edited by Kronos on Tue Jan 30, 2018 3:02 pm, edited 1 time in total.

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Re: Riding flat tyre. Still safe?

Postby march83 » Tue Jan 30, 2018 2:19 pm

human909 wrote:
march83 wrote:Yeah, that's terminal. You've done sufficient damage to the tyre's threads that it can't be trusted. Bin it and move on. Chalk it up to the price of staying safe.
How have you made that assessment? Treads are highly flexible so aren't easily damaged by flexing. (HINT: The clue is in the name.)
THREADS not treads... Tyres and their sidewalls aren't designed to be crushed between the rim and the road. At some point between 1km and say 100km (just to pull a number out of the air) of riding on a flat tyre the rim will have cut into and destroyed the sidewall of the tyre by damaging the THREADS in the carcass. I'm betting that the point is much closer to 1km than to 100km and that 7km is probably well beyond the point at which damage has occurred. Re-inflating the tyre may expose weak spots, or maybe it won't - maybe hitting a small bump mid corner at 70km/h exposes the weak spot. Either way, I think the tyre should go in the bin.

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Re: Riding flat tyre. Still safe?

Postby fat and old » Tue Jan 30, 2018 2:53 pm

When I was a kid there was another kid lived around the corner. Rode around on a 28 incher for months with no front tyre at all. :lol: Eventually trashed the wheel, and we dumped the thing at the creek, found another dumped one that was sorta ok and put it on. On and on the cycle went :D

Yeah, we were poor in that area back then. Joe Dirt poor.

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Re: Riding flat tyre. Still safe?

Postby Arbuckle23 » Tue Jan 30, 2018 3:45 pm

fat and old wrote: Yeah, we were poor in that area back then. Joe Dirt poor.
Luxury (in my best Yorkshire accent) :D

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Re: Riding flat tyre. Still safe?

Postby baabaa » Tue Jan 30, 2018 4:02 pm

Did you hear a small bang or a hiss? If not it could just be a leaking tyre valve.
If you rode the bike with a slow leak and made it home with some air in the tyre I would say all is good in terms of the rim and the tyre being safe but the tube may need a patch or a check of the value. Do a google on presta vs. schrader valves, pump up the tyre hard and give both a good gob of spit ( if you can find a drooling bloodhound dog even better....) or a few drops of water and detergent to see if you can get it blowing bubbles. Prestas types do need the little screw top thing snugged down and can loosen at a point which they know is the least expected.

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Re: Riding flat tyre. Still safe?

Postby human909 » Tue Jan 30, 2018 4:16 pm

Kronos wrote:Eventually if you keep riding on a rim like that you have a good possibility of wearing a nice little flat spot in your round rim making it entirely unusable forever. It's not really rocket science...
No it isn't but you are don't seem to be making sense. Even if you were wearing your rim (unlikely) because it is rolling not sliding, it would be even as the wheel turns so no flat spot.
Kronos wrote: Riding on concrete pavement/bitumen on alloy wheels is the equivalent of riding on a piece of sand paper. I don't need to figure the results I've seen them before. Eventually you're gonna wear straight through the tyre and be riding metal on concrete/bitumen.
Eventually our sun is going to die out too. In practice you need to do a lot of riding to wear through to metal on road and before then your really should have stopped. In my experience limping home has none of these 'eventually' problems.
Kronos wrote:You wouldn't drive a car on a flat tyre, why is your bike any different?
Yes I would if I had no other choice and it was safe to limp home.
Kronos wrote:Just walk or phone a friend.
That is a choice. I've chosen not to in the past and kept using the tyre and rim for years afterward (still am)....
march83 wrote:THREADS not treads...
Sorry for the typo. Point still stands. The threads aren't going to get damaged but being crushed inside of ''rubber'. The are flexible. Sure if you CUT the threads then there is a good reason to be worried, but your would generally need penetration of the rubber to do so.
march83 wrote:I'm betting that the point is much closer to 1km than to 100km and that 7km is probably well beyond the point at which damage has occurred.
Hell of alot of assumptions there. Speaking from experience I've had no issues.

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Re: Riding flat tyre. Still safe?

Postby Kronos » Tue Jan 30, 2018 4:26 pm

human909 wrote:
Kronos wrote:Eventually if you keep riding on a rim like that you have a good possibility of wearing a nice little flat spot in your round rim making it entirely unusable forever. It's not really rocket science...
No it isn't but you are don't seem to be making sense. Even if you were wearing your rim (unlikely) because it is rolling not sliding, it would be even as the wheel turns so no flat spot.
Err no... It isn't all equal :lol: Every time you brake you're putting a stopping load on a particular part of your rim. It isn't all equal. When you stop you have some inertia before you come to a full stop and at that point your motion is exerting force on a particular part of the rim.
human909 wrote:
Kronos wrote: Riding on concrete pavement/bitumen on alloy wheels is the equivalent of riding on a piece of sand paper. I don't need to figure the results I've seen them before. Eventually you're gonna wear straight through the tyre and be riding metal on concrete/bitumen.
Eventually our sun is going to die out too. In practice you need to do a lot of riding to wear through to metal on road and before then your really should have stopped. In my experience limping home has none of these 'eventually' problems.
It's not like that either. By 7km I'm gonna have a fair idea that you will have run over something to put a hole in the canvas and your rim will continue to be worn through. Not only that, you're likely to wear the sidewall of your tyre also which is not designed to be worn through.
human909 wrote:
Kronos wrote:You wouldn't drive a car on a flat tyre, why is your bike any different?
Yes I would if I had no other choice and it was safe to limp home.
Please go to your nearest department of transport and hand in your license and get off my road. You're a menace to society with that belief and endangering every other motorist on the road. Nah, you don't do that... you pull up and phone a friend, or walk.
human909 wrote:
Kronos wrote:Just walk or phone a friend.
That is a choice. I've chosen not to in the past and kept using the tyre and rim for years afterward (still am)....
Just because you do it doesn't mean its a good practice. Assuming its a fully deflated tyre the practice is no good... Assuming a road bike tyre in the world of the average senses and average rim widths anything under 80psi can be dangerous. If your tyre stays above this pressure you're good to continue to ride for a slow leak as far as needs be to get home. Assuming an average mountain bike you could still ride on 20psi. However, not everything is average. In this case we assume the rider was riding on a flat tyre which is just not acceptable in any sense.

K thnks bai...

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Re: Riding flat tyre. Still safe?

Postby fat and old » Tue Jan 30, 2018 5:44 pm

Kronos wrote: Just because you do it doesn't mean its a good practice. Assuming its a fully deflated tyre the practice is no good... Assuming a road bike tyre in the world of the average senses and average rim widths anything under 80psi can be dangerous.
Not really. Maybe if you're racing a crit, or bombing down Falls Ck? Otherwise, nah, it's ok to 45-50 at least. Based on 74KG rider, 23mm tyres on older Kysriums. I don't pump mine until they get to 60 or so. 90Kg, 25mm tyre on newer fulcrums. No racing or bombing down mountains. I'd guess that OP is more like me than Nibali (maybe not the weight....). :)
In this case we assume the rider was riding on a flat tyre which is just not acceptable in any sense.
Better to say

In this case we assume the rider was riding on a flat tyre which isn't really the best thing to do, but hey....I wasn't there so who knows? :D

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Meanwhile, back in the ute

Postby Thoglette » Tue Jan 30, 2018 7:12 pm

Get yer ute and do 20km without tyres (Thanks Auntie)

Voda, did you have a completely fat tyre or an underinflated tyre (from a slow leak)? Your initial post suggests the latter*, in which case re-read Duck's post**.
vodafone_au wrote: In fact, I remember that my rim was hit by the ground at least 2-3 times during the flat-tyre riding.
The size of puncture could be small as I thought nothing was wrong when I re-inflated the wheel at home and pressed the bike and tyre few times. However, it eventually became flat again when I checked it again after few hours.
* That would rather ruin the doom-and-flame-fest this thread has become.
** It's always a good idea to re-read Duck's posts.
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Re: Riding flat tyre. Still safe?

Postby vodafone_au » Tue Jan 30, 2018 8:16 pm

Firstly, thanks all for all your kind advice. It was getting dark and I didn't really want to call my friends to pick me up nor was able to visit LBS near me. I'll probably use Uber or a cap if this happens again next time.

Duck! wrote:The tube may have suffered additional pinch-punctures from riding while deflated.
Thanks for the suggestion. I just found the tube only costs like $10 from 99 which isn't much. But I'll see what I can do with my brand-new puncture repair kit.

gorilla monsoon wrote:I just want to know how you ride 7km on a flat tyre.
uhm... just like a man? :D Tyre wasn't completely flat (maybe at least 30psi were remaining out of 120psi) so I was able to ride it to my home.

baabaa wrote:Did you hear a small bang or a hiss? If not it could just be a leaking tyre valve.
No bang or a hiss. I didn't even notice it until I felt something a bit weird and pressed the tyre with my fingers. And no, there is no drooling bloodhound dog around me :D but I just tried what you advised and I haven't found anything suspicious on my presta valve.

Thoglette wrote:Voda, did you have a completely fat tyre or an underinflated tyre (from a slow leak)? Your initial post suggests the latter*, in which case re-read Duck's post**. .
Thanks for the suggestions. I guess it was the "slow leak". I just reinflated it (120psi) and only a small difference was found when I checked it again after an hour.


I've never replaced my tube myself but I reckon probably now is the time. I'll try to inspect everything carefully according to everyone's advice and see whether I have some handyman skill. Then, I'll probably visit my LBS and buy some CO2 and an extra tube. :D

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Re: Riding flat tyre. Still safe?

Postby Kronos » Tue Jan 30, 2018 9:56 pm

It's probably just a slow leak in which case you could have potentially stopped at the service stations along route and pumped it up to max, 120 and then ridden home. You probably would have had at least 60 in it by that time. The downside in that situation is a whole lot of tyre squirm and a wheel that's harder to push as you found out. If there was pressure in the tyre you probably haven't done anything serious to the rim, maybe a few scratches. I would check for sidewall wear though as its not designed to be ridden on.

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Re: Riding flat tyre. Still safe?

Postby human909 » Tue Jan 30, 2018 11:44 pm

Kronos wrote:K thnks bai...
Kronos. You are not making much sense and honestly you are making things up as you go.

As somebody who HAS ridden home on a completely flat tyre I can tell you that most of what you describe do not occur. Your rims are more than strong enough, nor are they subject to abrasion. You are simply rolling on rubber covered metal. Naturally you have minimal capability to absorb bumps so even your odd raised pavement joint presents rim danger. But you are LIMPING your bike home so you are paying attention to that sort of stuff.

As far as braking goes... Why would you brake on a flat tyre while limping your bike home? Capable braking and cornering go out the window which is no surprise at all. But again that isn't what you'd be doing.
Kronos wrote:You're a menace to society with that belief and endangering every other motorist on the road.
Huh? What motorists on the road? "If I had to" sort of implies there are not other motorists on the road. Being stuck in a remote place might mean a 50km walk, it might mean a 200km walk. And what part of 'safe' and 'limp' don't you understand?

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Re: Riding flat tyre. Still safe?

Postby Kronos » Tue Jan 30, 2018 11:55 pm

I'm pretty sure at this point you've got no mechanical knowledge what so ever so please step away from the keyboard.

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Re: Riding flat tyre. Still safe?

Postby gorilla monsoon » Thu Feb 01, 2018 10:35 am

vodafone_au wrote:
gorilla monsoon wrote:I just want to know how you ride 7km on a flat tyre.
uhm... just like a man? :D Tyre wasn't completely flat (maybe at least 30psi were remaining out of 120psi) so I was able to ride it to my home. :D
So the tyre has gone from being completely flat in your first post to having 30psi in it in your last post? Big difference there, pick one. Maybe you should have mentioned that in the first place.
Not my circus, not my monkeys

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Re: Riding flat tyre. Still safe?

Postby vodafone_au » Thu Feb 01, 2018 10:22 pm

gorilla monsoon wrote:
vodafone_au wrote:
gorilla monsoon wrote:I just want to know how you ride 7km on a flat tyre.
uhm... just like a man? :D Tyre wasn't completely flat (maybe at least 30psi were remaining out of 120psi) so I was able to ride it to my home. :D
So the tyre has gone from being completely flat in your first post to having 30psi in it in your last post? Big difference there, pick one. Maybe you should have mentioned that in the first place.

I believe there was "some" air inside the tube although it was really minimal (could be not even close to 30psi).

Sorry if I made you (or anyone) confused :oops:


*Update: I checked the wheel, tube and tire today and found a small cut on my tyre and tube. Besides the small cut, there's no visible damage to the tyre and rim (although I later accidentally damaged the tyre from inside while I was trying to remove the tyre from the wheel). Replaced the tube (puncture patch didn't work...) and everything seems okay for now.
Last edited by vodafone_au on Thu Feb 01, 2018 10:34 pm, edited 1 time in total.

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