This tyre is too hard…

May 15, 2015 at 09:16 | Posted in bicycles | Leave a comment
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tyrehardI finally got around to buying a new set of tyres for my fixie; you may recall the one on the back was rather the worse for wear, and I had to rather hurriedly replace it with whatever I could get at the time.

Well, the new tyres arrived, and sat in the shed for a few more weeks until at last I decided to put them on the bike. All easy-peasy,I thought, and within a few minutes I had taken the old one off the front, ready to replace it with a shiny new one.

Put it over the rim; bit of air in the tube, tuck it in, press the other edge over the rim, la la la – I hummed to myself as I worked, figuring this was all be done in a few minutes and I’d be swishing along on my new rubber.

And then I got to the final bit of tyre – you know, the really tight bit that’s a bit of a fiddle to get one. It did feel very tight, but I went back to the other side, worked the tyre around, pulling it around – something that is usually enough to do the trick. But no, it still stubbornly refused to pop on. I had a go with a tyre lever; I have a flat yellow one that works well for this.Then I tried a more heavy duty one. And another. Then I snapped one of them in half. And then bent another. No joy. That last bit of tyre just was not going on the rim. I scratched my head. Why was this so hard? I’ve replaced hundreds of tyres over the years, and never had one this intransigent. I’ve also never snapped a tyre lever, let alone two.

I took the tyre completely off again, and started from scratch. Round we went, popping it on, la la la, until – the same problem. I wrestled with tyre levers some more, but nothing. This was getting ridiculous!

Mrs Chillikebab came out to see how I was doing, and I had to admit that I actually could not put the tyre on the wheel. She suggested I might have to put the old one back on and go to the bike shop, and that made me feel simultaneously cross and ineffectual. Buoyed up by anger, I had one last go at the tyre with two tyre levers, and – pop – it finally went on. Phew.

I got my pump and started to put some air in. Whoosh. The air was leaking out as fast as it was going in. I had ripped a hole in it with the tyre levers; something that all the books say to watch out for, but which I had never before done.

leversIncandescent with rage I grabbed one of the few intact tyre levers I still had left, wrenched the tyre back off the rim, took out the tube and patched it.

This was not going to defeat me. I started again, this time paying a little more attention to where the tyre bead was sitting on the rim as it went on. It was sitting quite high on the rim, quite firmly held in the groove around the edge of the rim. I realised that by squeezing it in I could pop it deeper into the rim, against the rim tape. This gave me much more slack at the other side, and it was a doddle to pop the last bit of tyre over with just my thumbs. All so easy. As I then put air into the tyre, I could hear the tyre bead popping into its correct place all around the tyre.

So why the dramas? Have I never had a rim with such a pronounced groove just around the rim before? I have no idea, but I was able to put the rear one on with no fuss at all – and this is a different rim (the original Salsa one, rather than the Velocity one on the front).

So finally I was done. My thumbs hurt, I was dirty and sweaty, had broken four tyre levers and spent nearly an hour wrestling with it. But there is always that slight glow of satisfaction that comes with overcoming adversity…

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Tyre failures and inflationary pressure

September 2, 2013 at 22:17 | Posted in bicycles | 2 Comments
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tyrebulge I have, in the past, been a vocal supporter of Conti SportContact tyres.  I’ve been running the 32mm wire bead version of this tyre on the fixie (and also a tourer, whilst I had one) for many years, with huge success. They are grippy, highly puncture resistant, they roll well and last for ever. I’ve had examples of these tyres that have lasted well over 10,000km, and even when the kevlar was starts to show through the rubber they just keep going.

Interestingly though, others have voiced a dissenting view – that they have found they just didn’t last long, and disintegrated on them rather quickly. Caveat emptor, and all that.

I have to say, my own faith in them was temporarily shaken recently. I was riding to work, and could hear this ‘tink tink’ noise every time I used the front brake. It was clearly something on the wheel, but even though I stopped a few times to have a look there was nothing obvious – no bit of gunge stuck to the tyre than might catch on the brake callipers, and nothing on the rims. When I got to work I had a proper look, and was somewhat alarmed by what I found. The tyre was bulging off the rim, and the sidewall of the tyre seemed to be splitting. Along the split there was threads hanging off the tyre, and it must have been these I could hear hitting the brakes. Even more worryingly, when I looked around the rest of the tyre, it seemed as if similar threads were coming away all around.

tyreshreddingThis was very very strange. This was the first tyre I had mounted since the bike got a new front rim. Could it be that the tyre was not sitting on the new rim very well, and it was somehow putting pressure on the sidewall? I took a look at the rear tyre, and was even more alarmed to see that it too seemed to be shedding threads. This is the original rim that came with the bike, which made the rim hypothesis rather less likely.

I hotfooted it down to the LBS to get their opinion – and a new tyre, so I could safely ride home that evening. I showed it to the mechanic, and he quickly said, ‘I’ll just let the air out of that tyre before it blows up in our faces…’ He examined the rim, checked the wheel for trueness and so on, but there was nothing obviously wrong. I showed him the back tyre, and he was also a bit nonplussed, although he did point out that the tyre was pretty worn. It hadn’t really occurred to me that they were getting worn out. I guess I’ve probably ridden about 5,000km on those tyres since they were new, so compared to my previous SportContact experiences they are just broken in. I mean, you can even see a glimmer of tread pattern in a few places!

I got a replacement tyre on the front (another SportContact – I’m not ready to give up on them yet). The LBS guy didn’t think the rear one was a problem right now, although he did recommend I keep a close eye on it. And then I rode home, contemplating whether getting 5Ks out of a tyre was reasonable, and/or if the stories I have heard about Conti’s quality control being a bit variable were true, and the experiences of some of my correspondents with these tyres.

And then I had another thought. Around the time I got those tyres, I also got a new floor pump, as my old one gave up the ghost. It was very cheap, but seems to work just fine. However, I have always had a nagging doubt about the accuracy of the pressure gauge.  At the shop, the guy had asked me what pressure I usually inflated it to, and accordingly pumped it up to 85psi using his fancy shop pump – the maximum recommended for the tyre, and what I usually do it to at home.

When I got back, I attached my cheapo pump to the valve, fairly confident that the tyre was at or around 85. I put in one small stroke of air to stabilise the reading, and…   my gauge only read ’60psi’. Ooops. So it seems that I have been significantly over-inflating the tyre for it’s whole life. Who knows what it was getting up to, but I guess it could easily have been in excess of 100psi. Could it be that this is the problem, and that the sides of the tyres are literally cracking under the pressure?

Time will tell if the new tyre lasts better now I have inflation under control, but I suppose the moral of this story is if you have a cheap pump, don’t rely on the gauge!

What to do with a dodgy tube?

October 2, 2012 at 21:11 | Posted in bicycles | 2 Comments
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My rear tyre kept going flat. Just slowly, but obviously enough that I was putting much more air into it than the one on the front. Then, on Wednesday, I got my bike out of the garage to go to work and it had gone really very soft.

A puncture. I’d been putting it off, but now I had to do it. Luckily I had a bit of spare time, so I quickly felt around the outside of the tyre. I quickly found a large bit of splintered glass embedded in the rubber. ‘That’s probably what is was.’, I thought, and rather than taking the wheel off (no quick-release on the fixie) I just levered the tyre off at the point and pulled a bit of the tube out to patch the hole. If the hole was there it was too small to see, and I couldn’t feel any sharp edge inside the tyre either , so the splinter seemingly hadn’t got through the kevlar puncture protection layer. Whatever – I had a new tube, so I whip the wheel off, replace the tube, get it all back together and off we go – all done and dusted in less than ten minutes.

This weekend, I had a spare moment, so thought I’d patch up the old tube. Put some air in, put it in a bowl of water and go around to find the hole. Nothing obvious at first, but then it was quite a slow puncture. Put some more air in to stretch it a little, and go around more carefully. That tell-tale stream of bubbles remains obstinately absent.

Put more air in to really stretch it father than recommended, and go around really carefully, and inch at a time, pulling it as I go.

Nothing.

All very strange. A very very very slow puncture? Dodgy valve? Who knows. It’s now been inflated in the garage for two or three days, with no apparent air leakage.

So now I’m debating what to do with the tube. Of the options below, which would you recommend?

  1. It’s obviously fine. Pack it up in your seat bag as your spare.
  2. It’s obviously dodgy. Chop it up and use it to pad out that new rear light fitting that’s too big to fit securely on the seat stays.
  3. It might be dodgy. Buy a new spare, but keep it for emergency use.
  4. Give it to a friend as a gift.
  5. Eeeeygh, I can’t believe you tested a used inner tube in your kitchen sink. That’s so unhygienic.

Flat tyres

February 6, 2012 at 22:59 | Posted in bicycles | Leave a comment
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I hardly ever get punctures. Almost never. Just don’t believe in ’em. The last time I had a puncture was in March, and the last time before that was – well, actually I don’t remember. In fact, I stopped getting punctures when I started using Conti Sports Contact tyres. Now, I’m not big on product endorsement, but I do love those tyres. I run the 32mm version, and they sit on the Salsa Cross rims beautifully. They roll well, are grippy like anything, and, well, never get punctures. (It’s probably worth mentioning, in the interests of balance, that upon mentioning my preference for these tyres to someone in the Sydney cycling community, they launched into a diatribe about how awful they were, now they got continual punctures, and how they fell apart really quickly. And the LBS near work won’t stock any Conti tyres, as they think they are unreliable. Caveat Emptor, as they say.)

The last time I changed the tyres on the fixie was, erm, well actually I’ve never changed the front tyre. It’s the one that came with the bike four years ago. The rim is nearly worn through, the hub bearings need replacing, but the tyre is still going strong after what must be at least 25,000 km.

Well, that’s an exaggeration. Not the longevity of the tyre, but the notion that it is ‘going strong’. Actually it’s pretty knackered, with the kevlar belt showing through in some places and big cuts and holes in in. There’s also enough glass embedded in it to open a bottling plant.

And there’s a lot of broken glass around Sydney at the moment. Lots of public holidays means lots of drunken louts throwing beer bottles into the street. From the amount on the bike paths, you could almost believe people break glass there deliberately.  Surely no Sydneysider would be so inconsiderate? That’s the kind of behaviour  you might expect from Melbournian cricket celebrities, but not the people of this fine city.

Anyway, perhaps inevitably, my tyres have succumbed to the glass. Both of them, in fact, in close succession. A flat on the front on Friday, and a flat on the back tonight. The one tonight was particularly painful, as I was on a three-line whip to get home early so Mrs Chillikebab could go out to her dance class. I wheeled the bike out of the rack at work, and realised I had a flat. I had ten minutes to spare, so set to to quickly change the tube for the spare, only to discover the spare (which I have never used, having bought it years ago and tucked it into my saddlebag) was useless – the valve just came off the tube when I attached the pump to it.

This meant I was going to have to actually find and fix the hole in order to ride home. And the clock was ticking. I examine the tube looking for the hole. No, can’t see it – damn, precious minutes wasted there on a fruitless search, I’m going to need a bowl of water. Rush into the bathrooms, fill a basin and work my way around looking for the tell-tale stream of bubbles. I start at the valve and work around to the right, going over the whole tube  only to  find the hole just to the left of the valve.

Quick, rough it up and get the rubber cement on it. Now wait for the cement to go tacky.Wait some more. WAIT! You know you have to wait. I tap my heels impatiently, and, able to stand it no longer, peel off the patch and stick it on. It slides around and the cement is runny under my finger. Too soon! Oh no, am I going to have to do the whole thing again? I will it to stick, holding it on as I rush back to the bike. Put a little air into it, back under the tyre, pop the tyre back on, and now just to pump it up.

I had had a nagging doubt about this part of the operation from the beginning. The last time I used my mini-pump was the last time I got a flat, and it didn’t really work then.  It worked even less well this time. As I pump, the air leaks away, so I pump harder – pumping like a dervish I manage to get just enough air in to get me off the rims. Jeez, I need a new mini-pump.

I get going – a few hundred metres down the road is a bike shop, so I pop in to borrow a pump to put some air in the tyre. More time wasted, but I know that I’ll make up the time compared to riding with a nearly flat tyre. And finally then away, scooting off through the traffic. (I’m in a rush, but I’m still the slowest cyclist on Pyrmont Bridge. People really do need to ride slower on that bridge. Really, they do. Cyclists do themselves no favours zipping across there weaving around the pedestrians – and I catch them all up at the lights anyway.)

I get home with seconds to spare. Mrs Chillikebab does a quick handover as she heads out the door (Baby fed at 5, had bath, looks tired. Toddler ate well, lively, seems to be getting the hang of the potty) and vanishes.

I stand surveying the scene; the usual carnage of toys everywhere. Toddler wants a cuddle but I am hot, sweaty, and my hands are filthy with oil and brake dust. ‘Cuddle now!’, she wails, and then wees on the floor. Baby Chillikebab just smiles up at me from her mat, and then contentedly fills her nappy. enough to start it oozing out around the legs.

Tomorrow, I get new tyres…

Flat as a tack

March 24, 2011 at 22:13 | Posted in bicycles | Leave a comment
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I got that flat feeling today. On the way back to the office from a meeting I turn the penultimate corner prior to my destination, and it feels all weird. Like the back wheel skidded out a little.I continue to roll along, and the weird feeling continues. It just all feels wrong, like some alien force is trying to take over the bike.

I pull up outside the office, and feel the tyres. Sure enough, the rear one is nearly flat. I have a puncture. Bugger. ‘This can’t be!’, I think. ‘I never get punctures!’.

It’s kind of true. I haven’t had a puncture for about four years – ever since I started riding on Conti Sports Contact tyres. I’m not really one for brand endorsements, but I love those tyres. I guess they travel about 5000 km per year, so that’s 20,000 km without a puncture. And they are grippy and fast too.

I get up to the office to survey the damage. I also have a quick check of the equipment I have with me; I am now so complacent about punctures that I quite often neglect to take any of the basics with me. Tonight I am in luck, though. I have a repair kit, tyre levers, a new tube, and the all important spanner to get the wheel off – it’s the rear wheel on the fixie, so it doesn’t have a quick release.

The first challenge is getting the wheel off. I hardly ever do it, and the last time the nuts were tightened were at the LBS. For a few minutes I wonder if my little spanner is going to give me enough leverage, but with some brute force they turn. I examine the exterior of the tyre, and immediately see the culprit. A tack is embedded in the rubber. I’m surprised that the tyre didn’t go down much faster; I must have ridden several hundred metres with it pushed into the wheel.

The good news about it being so obvious is that I can repair the tube easily, as I know where the hole is. I lever the tyre off the rim at that point, and pull out enough of the inner tube to carry out a repair. I have a sudden thought that the  puncture repair kit might contain a four-year old tube of dried-up rubber cement, but luckily it’s unused and the seal is not broken.

Thee is one thing about puncture repair kits that bugs me, though. Why on earth do they make the patches so huge? This particular kit comes with two different sizes; the small one is about three centimetres by two centimetres, and the large one is about double that. Do people actually mend holes that are two centimetres across? Good luck to them if they do, but my punctures are invariably little pin holes that only need a small patch about the size of a thumbnail. Huge patches are really hard to apply; you have to roll them around a crease in the tube and it’s hard to get them flat and bonded all the way to the edge. I take some scissors to one of the patches and trim it to about a third of its original size to make it usable. (I’ve never found that not having a tapered edge to the patch matters. I remember at one time you could buy sheets of patch stuff and just cut it off in squares as you need it.)

Rough up the tube with sandpaper (repair kits seem to come with little cheesegrater things these days, but I prefer old-school and evidently remembered to put a small square of sandpaper in the repair kit) and apply a coating of rubber cement. Then wait. And wait some more. And then just a bit longer for luck.

I peel the backing off the trimmed patch, and place it over the hole before squeezing it between two 20c pieces to hold it in place. After a minute or so, it’s ready to go. (Except there’s no French chalk. Honestly, standards are slipping. in my day, young man, let me tell you that you always dusted your repair with powdered French chalk.)

Put a little air into the tube and relocate it, then pop the tyre back onto the rim. Check the tube isn’t being pinched by the tyre bead, and then inflate the thing properly. This is where things get a little difficult. I do have a mini-pump, but I’ve never used it. I purchased it ages ago when my previous one fell off my bike and was squashed under a car before I could retrieve it. My old one had two holes, one for Presta and one for Schrader. This one has only one hole, apparently for Schrader. And there’s an adapter thingo clipped under the lever.

I have no idea how this works. I know such adapters exist, but I’ve never used one.What do you do? Put it into the pump, and then onto the valve? Screw it onto the valve and then put the pump over? Do I use the lever on the pump before or after inserting the adapter thingo?

I actually still don’t know the right way, but I do know one thing. The answer to ‘how do these adapter thingos work’ is ‘badly‘. I tried it every which way, but each time I got a moderate amount of air into the tyre any subsequent thrusts of the pump wobbled it enough to cause more air to leak out than I was pumping in. At this rate I was going to be riding home on a tyre barely inflated enough to keep me off the rims!

I eventually worked out how to get some air in, by jamming the wheel upright under my desk with the valve at the top, and then pulling upwards very hard on the valve as I pumped. A manoeuvre that could be tricky at the side of the road. Perhaps I need to invest in a better pump.

Anyway, I do actually quite enjoy mending punctures, provided it’s not at the side of the road in the rain when you are late. I like the satisfaction of actually mending something that is damaged – a feeling that is rather rare in today’s disposable society. I know several friends who think I am bonkers, and just buy a new tube each time; I’ve been known to rescue their punctured tubes from the bin, repair then, and present them back to them to use next time.

Not that I’m looking to get another puncture any time soon, thanks. But in another 20,000 km or so’s time I might be ready!

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