A limerick a week #194

If you’re gonna be stupid, be lucky too!

So, there I was on my bike, peddling in an easterly direction along the South Deeside road and trying to impress SID, the Speed Indicating Device, as I entered the new-build settlement at Riverside of Blairs when, BANG!

I thought “Gosh, that was loud!” (or words to that effect) and although the flapping-cum-graunch sound of a deflated tyre implied a puncture, the explosive retort suggested it was just a tad more serious than that.

The truncated route!

And indeed, it was. I’d just experienced a catastrophic failure of my front tyre at about 21mph. Fortunately, I was on the flat heading straight ahead and the tyre stayed on the wheel. Had I been tanking downhill or on a corner then I suspect it would have come off the rim, jammed in the forks, and I’d have crashed – perhaps heavily.

What a catastrophic tyre failure can look like from the outside.

And d’you know what? I’d have only had myself to blame.

I’d inspected the bike before setting off and the front tyre looked a bit bockety in one place. I actually took it off and re-seated it, but the distortion remained. If I’d examined the inside of the tyre before re-fitting it, I would have seen something that shouted out loud when I examined it after the event (I also wouldn’t have ridden on it!).

Nearly all bicycle tyres are manufactured cross-ply. That means the rubberised woven material that forms the casing has its warp and weft at 45° to the direction of travel. In my tyre the weave had split at one point along the angle and compromised the structural integrity of the carcass; hence the distortion when fitted to the rim and inflated to 100 psi.

… and from the inside. In this case, the woven casing had split along the direction of the warp (or weft, whichever) distorting it when pressurised and it became a blowout just waiting to happen.

The simple moral of the story is to never trust a tyre that doesn’t look right. That’s even more true if, like me, you’d considered the tyre to be a bit ‘iffy’, but decided to ride on it anyway whilst assuring yourself that things would be fine as long as you never went too fast down hills or around corners. It was lucky that I did take things cautiously. It was also lucky that ‘management’ was just about to start her lunch break and was able to rescue me several miles from home.

… and the good news, if you believe the advertising, is that the new tyres I have ordered will turn me from a ‘trundleur’ into a speed merchant – aye, right!

Here’s the limerick:

As a cyclist you’re playing with fire
If you ride with a bockety tyre
‘Cos if it explodes
When you’re out on the roads
The outcome, I fear, may be be die-er!

Postscript#1: From the late-lamented Pâtisserie Cyclisme website… 

“The trundleur is a cyclist who enjoys riding any kind of bicycle, at their own pace for the sheer enjoyment of it. They frequent cafés, stopping to enjoy the view, converse with friends or simply sit and reflect. The trundleur does not care for recording their rides obsessively, nor do they obsess about their speed or beating their fellow cyclists.

The trundleur finds a simple joy in the act of riding a bicycle.”

Je suis un trundleur and ‘management has decided, that being the case, then she can only be a pootleur

Postscript#2: The website www.bicyclerollingresistance.com rates, ranks and compares bike tyres. My road bike’s tyres were originally Schwalbe Lugano and the new ones on order are Continental GP5000. So why not see what that website comes up with?

No contest, apparently. The GP5000s get a 5/5 rating and come highly recommended whilst the Luganos score a measly 1/5 and are not recommended at all. In terms of rolling resistance, the GP5000s each consume 10.7 watts at my riding pressure of 100psi travelling at 18mph whereas the Luganas each come in at a whopping 22.6 watts.

The graphic, below, shows the ‘performance’ of the tyres at each of nine variables. No tyre is ‘best at everything’, so the outer limits of the nonagon are an amalgam of the best performing tyre for each measure individually. Basically, it shows that the Luganos have better puncture resistance at the tread, but much greater rolling resistance at all pressures. The Luganos are only on sale as clearance items now, but originally came in at around £39 a pair whereas you’ll only get one GP5000 for that price!

Continental GP5000 performance vs Schwalbe Lugano tyres. The closer to the outside edge of the nonagon, the better. The cycling world seems generally to consider the GP5000s to be the best ‘all round’ tyre (which implies some may not be all round – octagonal, perhaps or just plane square?)

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LanterneRouge

😎 - Former scientist, now graduated to a life of leisure. - Family man (which may surprise the family; it certainly surprises him). - Likes cycling and old-fashioned B&W film photography. - Dislikes greasy-pole-climbing 'yes men'. - Thinks Thea Gilmore should be much better known than she is. - Values decency over achievement.

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