In Search of Schrodinger’s Puncture

January 8, 2023

As my adventures in bike maintenance continue, it never fails to amaze me how something so simple as fixing a puncture on my bike seems to throw up a new problem every single time. But as puncture season (approximately October to September round here) continues in full swing, the surprises continue, and now I’ve apparently got an intermittent puncture which is a new one on me.

I’ve long argued that there’s no such thing as a self-fixing puncture, although I also believe in ekeing out a slow puncture for as long as I can, mainly because as soon as you actually repair them you just get another one. So when I set off home from the Pepperpots last week and discovered my back tyre was flat as a pancake, I pumped it up (hooray for the miracles of my tiny folding track pump) and took it home, meaning to deal with it later. The next morning it was still apparently holding air so I assumed it was just a very slow puncture and took the bike into town and back. The next day it was a little soft so I pumped it up and then we seemed to settle into the normal pattern of pumping it up daily until I had the time and the energy to fix it properly. Fast forward to the end of this week and it suddenly went flat on me after five miles. Fair enough, slow punctures usually become fast ones in the end, so I pumped up enough to get home and resolved to fix it at the weekend.

Anyway, this afternoon I duly took the back wheel off, removed the (once more flat) inner tube and started hunting for the culprit, to no avail. No hiss of air when I pumped up the tube. No tell-tale bubbles when I dunked it in a bucket of water, not even from the valve. And nothing inside the tyre that might have caused the puncture in the first place. Odd. This tube does have slime in it (apparently, the bike shop replaced it when I was getting the bike serviced) but I can’t see any sign of where it might have sealed up a hole. Or work out how it could do it while the bike was sitting in the garage with a flat tyre. But if I couldn’t find the puncture I couldn’t fix it so all I could do was put the tyre back on, pump it up again, and hope for the best. Perhaps my bike just wanted the attention. Or decided I needed the practice. Either way, we will see what tomorrow brings.

Meanwhile, I do have Tannus inserts on order, which I hope will sort the problem out for once and for all. Although I do realise that the Puncture Fairy laughs in the face of such optimism.


September 29, 2020

I suppose I should have guessed when I got my back wheel off, tyre off, whipped on a new inner tube, and got it all back together again in record time on Saturday that I was riding for a fall…

Rewind to Friday afternoon, when I had decided to tackle the slow puncture in the back wheel which had been evident for a week. Being a grown up cyclist who doesn’t ignore problems in the hopes that they will go away *ahem*, I felt that showing up for our first group ride in six months with a tyre that needed to be pumped up every morning was a bad example, so I gritted my teeth, took off the back wheel and brought it inside and surprised myself by taking less than an hour to fix the puncture, even though it did take me two patches and much cursing of the declining quality of puncture repair kits in this modern throwaway age (or possibly it was user error – you all knew you weren’t supposed to peel the plastic film off the top of the patch, right?) and/or my increasing impatience with the glue drying process. I wasn’t entirely happy with the resulting repair but thought I’d got the tube air tight, got the tyre back on with a minimum of fuss and … woke up on Saturday to a flat tyre again.

By this time I was out of patches and out of spare inner tubes for that wheel (because for reasons which have got lost in the mists of time I have a front wheel which takes Schraeder valves and a back wheel that takes presta valves and even though I’ve since replaced the back wheel and specifically asked the bike shop to sort this out I still do) so I pumped up the tyre again in the hopes it would hold and cycled down to the bike shop to buy a new inner tube and a sheet of patching material, only having to top up the air once, cycled back, and efficiently swapped inner tubes before my afternoon coffee had got cold.

Of course what I hadn’t done was my normal test ride (essential whenever I’ve been anywhere near the bike with any sort of maintenance attempt) so when I set off on Sunday for the ride, my bike was doing the sort of ‘badum badum badum’ thing that suggests a wheel that is not perfectly round (there’s a pedestrian and cycle bridge in Bigtown that has been surfaced in such a way that it does the same thing, and you can tell if someone doesn’t regularly cycle over it by the slightly worried expression on their faces as they try and work out what expensive thing has gone wrong …). A quick inspection revealed that I had not properly seated the tyre at the valve so I sorted that out, happily escorted some families around the back roads and byways of Bigtown, cycled home, and was greeted the next day by a completely flat tyre…

No problem – by this time I’m a dab hand at getting wheels off and tyres off (if not on) so off comes the back wheel, tube inspected and it’s a mess (really, don’t ride on a poorly seated tyre, it’s very bad for expensive new inner tubes) and after two patches have failed to sort it out I revert to the old inner tube which I had been meaning to repatch and keep as a spare. Which is now, mysteriously, holding air again … (does the Puncture Fairy have a helpful cousin the Patch Fairy, who recognises when a cyclist is at the end of her tether, and slips into bike sheds to fix things?).

So that is now on the bike (with the other half’s help to get the tyre reseated) and was fine this morning and fingers crossed that it will stay that way at least until the next Bastard Big Thorn comes along. In which case, I might just revert to my previous tactic of keeping the thorn in place and pumping the tyre up every morning because honestly, it seems more effective than my efforts to sort things out properly have been to date.

Only another five months of hedge-cutting season to go …

Slow, Slow

July 18, 2020

Alert readers may remember that at the beginning of May, I was complaining about a slow puncture in the front tyre of my bike. Regular and alert readers may not be surprised to learn that as of this morning, I still had it (and was still complaining about it, but not enough to do anything about), although I have found that since I started riding down daily for the paper again it has got slower.*

Now if I’ve learned anything about riding a bike regularly for transport it is that there’s no such thing as a self-healing puncture, however much you may want there to be, and there’s also no such thing as a slow puncture that doesn’t become a fast puncture just when it’s least convenient. Nevertheless, I have spent the last two and half months starting each bike ride with pumping up my front tyre – first because I had run out of patches and the bike shop was by appointment only, and then, once we’d got hold of a spare inner tube, because, well, if your bike’s tyre holds air well enough to get you into town and back, and you’ve got a nice track pump so it’s pretty quick to pump it up every day, and it can take you a good hour to wrestle the thing’s supposedly puncture-resistant tyres off and on and you already wasted an hour of your life doing so and still not fixing it – why mess with the situation? Feeble, I know, but before you cast the first stone, tell me you haven’t ignored a problem that was merely politely clearing its throat and mentioning things rather than waiting until it was knocking you to the ground, pinning you down and shouting about them in your ear, metaphorically speaking?

ANYWAY at this point, I would like to surprise you all by announcing that I have fixed the puncture BEFORE the problem became acute. And that it only took me half an hour, including also cleaning and oiling the chain, straightening the back wheel and, ahem, somehow unindexing my gears so I now no longer have the bottom gear (I feel that only I could do this while attempting to fix a front tyre). I have put in a new inner tube and patched the old one to act as a spare (the hole turned out to be on the inside of the tube, opposite an existing patch, as if a bastard big thorn hadn’t just made it through the supposedly puncture resistant tyres and the outer skin of the inner tube but all the way out the other side. When blackthorn sets out to puncture a tyre, it does not mess around).

The reason for this flurry of maintenance is that we are thinking on going on a little adventure tomorrow and it would be inconvenient to spend most of it at the side of the road muttering imprecations at my past self about the perils of ignoring slow punctures. It doesn’t mean I won’t actually get a flat tyre – for what has this whole post been but a red rag waved energetically in the face of the puncture fairy – but at least it won’t entirely be myself to blame.

* This chimes with my observation that bikes that are ridden regularly don’t need their tyres pumped up anything like as often as bikes that just sit in the shed. Perhaps there’s some clever physics explanation of why that should be, but I’m beginning to think that it’s just that bikes want to be ridden and if you don’t ride them they self harm.

Flattening the Tyres…

May 3, 2020

So today’s excitement was the chance to ride down to my pal with the hens to deliver some of our empty egg boxes and surplus chilli and tomato plants, in exchange for some eggs.

plants in Brompton basket

When it comes to transporting tender young plants, the Brompton – or rather its basket – comes into its own. With six pots each wrapped up in a protective sleeve of newspaper and snugly sitting in the basket, all was well until I was half way down the road and heard the all-too-familiar bump-bump-bump of a flattened back tyre.

If you follow me on Twitter, you may be aware I’ve been plagued by punctures recently, compounded by my inability to do even the most basic bike maintenance. Over the last couple of weeks I have spent a total of two and a half hours effectively turning two fast punctures into two slow punctures, one on the front tyre of my big bike and one on the bike trailer. During the course of this effort, I have also run out of patches in my various puncture repair kits and discovered that I am now managing to fail at the one part of the puncture repair process I used to be vaguely competent at – actually patching the hole. This means every trip out on my big bike now starts with pumping the front tyre back up to a reasonably pressure and hoping it holds for long enough to get me home – a recipe for disaster, as I well know, but still preferable to spending any more time swearing at inanimate objects in the hope that that will work where brute force, cunning, and supposedly failsafe methods have all failed (actually, sometimes it does) (and before you dive into the comments, thank you but I am already using the puncture resistant tyres you are about to recommend, and have tried slime, and I’ve watched the video with the zip ties, and the problem is I’m just very bad at fixing bikes and blackthorn will go through anything).

Anyway, the good thing about puncturing the Brompton back wheel is that I have absolutely no intention of fixing it myself or even pretending that I wished I could – much to the disgust of some of the more old-school members of the Bigtownshire Cycle Campaign – so I won’t be wasting another hour or more of my time wrestling with another Marathon Plus tyre (on the other hand, I will probably be waiting a week before the bike shop can get to it – one of the downsides of everyone discovering the joys of cycling during lockdown has been that the few bike shops still operating are operating a waiting list). And the other good thing is that Bromptons are easy to just throw into the car so I avoided the walk of shame and sent the other half home to get the car and pick me up – the first time I’ve actually been driven anywhere for six weeks.

scenic route

And then we took the scenic route home so we could charge up the car’s battery properly after six weeks of nothing but short weekly trips to the supermarket and back. We weren’t sure if it was entirely necessary but decided better safe than sorry, the way the last two weeks have been going … and some flats are easier to deal with than others.

Slow, Slow, Quick Quick, Slow

February 22, 2019

A Public Service Announcement for All* Cyclists:

There is no such thing as a self-healing puncture. Nor, realistically, is there such a thing as a slow puncture: a slow puncture is a fast puncture that’s had the decency to warn you it’s coming. The correct response to such a courtesy from the P****** fairy, is to fix the puncture as soon as you notice it – or at least on the day after, when you don’t have to go anywhere. The incorrect response is to keep pumping up the tyre every morning in the hope that it will magically go away, until it chooses the most inconvenient time possible to become a full blown flat tyre. It seems obvious written down, so clearly this is absolutely not what I’ve been doing this week.

In other news, this is happening, almost a month earlier than last year.

daffodil blooming

I don’t wish to appear ungrateful at the current mild weather, but at this time of the year, the last thing I need is for spring to start speeding up on us.

* Or possibly just me

Slime vs Bastard Big Thorn: no contest

November 22, 2017

I was a little disappointed in my Slime inner tube when it failed me yesterday, but having investigated a bit more closely I’m inclined to give it the benefit of the doubt.

You know how frustrating it can be, trying to track down the source of a puncture with nothing visible to the naked eye, and no sign of what might have caused the problem? That definitely wasn’t the case with this flat.

second thorn

First thorn

I think Slime works by centrifugal force – as you rotate the tyre, it is forced out of the hole under pressure and then sets to form a seal. That assumes that the hole is on the outside of the inner tube, and that the Bastard Big Thorn(s) didn’t end up going all the way through the inner tube and out the other side.

extracted thorn

This wasn’t even the one that caused the worst damage …

As it is, my backup innertube was a normal one, so it’s going to have to battle through the thorns unassisted.

mud under mudguard

At least this shows my mudguards are doing their job

As you can see from the state of my bike when I took the wheel off, the local farmers have not been very assiduous at sweeping either the mud or assorted hedgerow debris off our road. I have now cleaned my bike, but that’s going to last until the next time I cycle out of our front gate.

Our neighbour up the hill actually has his own petrol-powered mini road sweeper (it’s like a giant carpet sweeper) because he was sick of his car getting punctures. I have to admit, I was amused by this at the time, but I might have to borrow it if today’s rain hasn’t swept the worst of the hedgecuttings away.

Punctureproof in Scotland

November 21, 2017

“Well, at least it will give you a chance to test if your new jacket* is Waterproof in Scotland”, the other half observed as he watched me don waterproof trousers and gaiters ready to cycle down to the station on my way to Embra this morning. As bright sides go, this felt less than compelling but as it turned out, by the time I had wrestled all the various bits of conflicting velcro that hold my rain gear together, stuffed dry socks and gloves into my bag (the only thing worse than spending the whole day in wet socks is putting wet gloves on to cycle home), and got the bike out, the rain had eased off, which if I’m honest is the way that I always hope raingear will work.

Feeling pleased that I had cheated the Weather Gods out of a home win, I headed off, not hearing the wry chuckle of the Puncture Fairy who when hedgecutting season is in progress, laughs in the face of puncture resistant tyres and – it turns out – Slime-filled inner tubes. At least, that was the conclusion I reached as I got to the main road and registered the thumpa-thumpa-thump of a flat tyre. Pushing the bike hurriedly home to grab the Brompton and a lift from the other half, I discovered that my raingear may or may not be Waterproof in Scotland but is not Breathable when Pushing a Bike Up a Hill in a Hurry so either way I end up damp, but at least I did get the pleasure of hopping out of the car when we hit the first morning tailback in Bigtown, unfolding the Brompton and cycling merrily away from the traffic.

Tomorrow (which, if the Met Office’s rain warning is anything to go by, looks like a good day for testing if the house is Waterproof in Scotland, never mind my jacket) I shall have to track down the source of the problem and discover whether dealing with a slime-filled inner tube which didn’t do its job is as nasty as people say. And then on Thursday I get to go to Embra all over again to kick off the planning for next year’s POP.

Did I say that I hadn’t been all that busy recently? Silly me.

* It claims to be ‘tested on Cornish clifftops‘ but a) that is not Scotland and b) you notice it doesn’t say whether it actually passed the test …

There Once Was a Bike from Devizes

August 27, 2017

I think I may have mentioned in the past that I have mixed feelings about bike maintenance. I understand the attraction  in today’s modern throwaway society of something that not only can be fixed, but which positively demands to be – and indeed maintained, cleaned, oiled, improved and generally tinkered with. How many other objects do you have in daily use that you can say that about?

I can also, in theory, see how satisfying it would be to be able to competently tinker with my own bike (especially if it means confounding the expectations of those who might assume by my gender and general unhandiness that I can’t). And over the years I have gradually picked up a few things, like how to use a pump to get air into a tyre rather than removing all the remaining air out of it (look, I started from a low base), how to get the wheels on and off, how to clean and re-oil a chain, how to replace the brake pads, and how to sort out a wheel that has suddenly gone skewiff because when I say I know how to get the wheels on and off I mean I still never manage to tighten them sufficiently the first time around. And I would estimate that, given enough time and a warm day and no helpful competent person around to do it for me, I can repair a puncture at least 50% of the time without wanting to burst into tears.

However, that’s just the start of it. And if I’ve learned anything about bike maintenance, especially if your bike is more than a few years old, it’s that, whatever the thing is that you’re trying to do, the answer is always going to be that it’s a bit more complicated by that. Because bikes might look like simple and easily understood machines but they have evolved over time and nothing seems to be compatible with anything else, and all bike mechanics will tell you (with a sorrowful shake of the head) that whoever did something to your bike last was a dreadful bodger and it’s amazing you’ve got away with it without coming a nasty cropper.

So when the other half mentioned in passing yesterday evening that my back tyre had gone flat, I knew I was in for a bit of a nightmare. And I wasn’t wrong. What should have been a simple fix of a tiny hole turned into a two-patch job that promptly didn’t take (patches go off, who knew?), the discovery that the thing that makes my back brake spring away from the wheel when I release the brakes had gone sproing and needed to be bent back, the related discovery that my brake pads had worn themselves crooked, the further revelation that my spare inner tube doesn’t fit my back wheel because my back wheel is narrower than my front wheel because a long time ago when I didn’t realise that you change anything on your bike at your peril that had seemed like a good idea, and the subsequent knock-on revelation that my back tyre is the wrong size for the rim. Oh, and my tyre irons are worse than useless but that the cheap hippo-shaped bottle opener I got in a Christmas cracker in 2009 makes a reasonable substitute.

Anyway. I have now purchased a slime-filled inner tube of the right, but also wrong, size which will likely solve none of these problems but just might get me through hedgecutting season if the P****** Fairy isn’t listening, and I have just had a lot of practice at getting my back wheel and tyre on and off, which will stand me in good stead if she is.

Remind me tomorrow to tighten up the back wheel one extra turn before it goes skewiff on me when I set off.

Always assuming there’s actually still any air in the tyre …

How the Other Half Live

September 29, 2016

In proof that no good deed goes unpunished, I was rewarded for my efforts to encourage cycling among kids yesterday with a puncture this morning that turned out to be not so much a Bastard Big Thorn as an entire twig which had somehow overcome my tyre’s puncture protection and got itself thoroughly embedded (I had passed the hedge-cutting tractor and wondered if I ought to worry, but I noted it was cutting hawthorn rather than blackthorn and decided I’d be okay… Big mistake).

Bastard Big Thorn

Fortunately I was visiting the office of a cycling friend so she helped* me wrestle with the tyre and provided a patch. Unfortunately, we were so focused on removing the Bastard Big Thorn and getting the tyre back on, we made the schoolgirl error of not checking the inner tube was actually holding air first. I was so demoralised when the tyre immediately went flat again that I let her get back to work and wheeled the bike to the nearest bike shop which has only recently opened (I like to think that Bigtown can only maintain three bike shops plus Halfords because of all the easy tenners they make fixing my punctures) and proceeded on foot to Aldi where I was intent on securing some bargain basement merino.

It’s not a part of town I go to that frequently, to be honest. It’s not a great road to cycle on and, Aldi cycling specials aside, there aren’t many reasons to visit, although possibly the bike shop will change that. But walking up that road, I realised that, unpleasant as it is to cycle on, pedestrians have it much worse. At least on a bike I can pretend to be a car and take a nice direct route, while pedestrians have to be penned in to prevent them from crossing the road in a straight line (after all, with cars enabled to make such nice sweeping turns, it simply wouldn’t be safe to let them cross where it would be convenient for them).

car desire lines

Car desire lines catered for; pedestrian desire lines thwarted.

Cyclists are considered to be an angry, organised bunch, but this sort of thing makes me wonder where all the angry, organised pedestrians are. If I actually spent any time on foot I’d be hopping mad at this sort of thing, all the time. It’s probably fortunate for the coonsil that I’m generally too lazy to walk if I can ride my bike and anyway already have my hands full moaning about the cycle provision. As it is, anyone would think they actually wanted us to drive …

* OK, she did it while I made helpful suggestions and passed her tools.

Bike Maintenance Redux

February 15, 2016

It’s fair to say the last two days have not represented a pinnacle of my bike maintenance skills. Yesterday, what was supposed to be a social bike ride turned into a puncture fixing refresher course involving a grand total of four inner tubes, something of a record for me (the inner tube with the leaky valve that was causing my front tyre to go flat in the first place; the ‘spare’ inner tube that had supposedly been repaired after the last puncture that proved not to be particularly repaired after all; the replacement inner tube hurriedly bought at Halfords which I punctured trying to get my Marathon Pluses back on; and the other replacement inner tube which the nice girl mechanic at Halfords fitted with practised ease in about the time it had taken me to work out which way round my front wheel went while simultaneously managing not to make me feel entirely the incompetent fool that she and I both secretly knew I was).

Today, with the sun shining and the frost confining itself to sparkling attractively on the grass, I set off for the paper with the only fly in the ointment being the fact that my front derailleur was proving difficult to trim so that my chain didn’t rattle against it, something that had been bugging me for a while. Unfortunately I had forgotten the cardinal rule of all bike maintenance: never ignore a new noise. I was just at the outskirts of Papershop Village when the chain snagged on what proved to be a sheared-off front derailleur

Fortunately, the bike was rideable home (as long as I didn’t hit too many potholes; this is harder than it sounds at the moment) as that would have been a long old walk of shame otherwise…

Off to the bike shop tomorrow, I think.