May 18 2015

Bike Monday for May 18, 2015: Riding on Air — The Upside of Inflation

Remember inflation? It was once the scourge of Western economies, and sooner or later it’s sure to return. But I’m not talking economics here. I’m talking cycling. And cyclists have every reason to embrace inflation. After all, it was the pneumatic tire that changed the bicycle from rich man’s toy into day-to-day transport for working men and women.

So check your tire pressure before your next ride. You’ll find the recommended pressure stamped on the sidewalls of your tires, though road conditions and load will likely dictate some adjustments. The late Sheldon Brown prepared a good primer on the subject, but at the end of the day, your own experience is what counts. Only one thing is certain: Properly inflated tires can make or break a ride. The upshot? It pays to invest in a good pressure gauge — the “pinch test” simply can’t be relied on. And if you want to make topping up as easy as possible, get a floor pump to use at home.

Lastly, don’t forget to bring a reliable frame pump whenever you hit the road. Or if that’s too much of a burden, at least slip a mini pump into a jersey pocket. There’s a broken beer bottle out there with your name on it. Be prepared!

Air Force

 

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May 16 2015

Heading Off Headset Problems

A lot rides on your bicycle’s headset, and most modern bikes are equipped with the “threadless” variety. This rather intricate assembly allows the front wheel to swing smoothly from side to side, and when paired with a suitable stem, it also keeps the fork securely attached to the frame, a matter of no little interest to the thoughtful cyclist. Here’s an exploded view of a typical threadless headset, thanks to Keithonearth and Wikipedia:

Threadless Headset Schematic

The pictured headset uses cartridge bearings, but loose ball bearings in retainers are common, too. The upper and lower races are press-fitted into the bike’s head tube, and if they’re improperly bedded, or if the grease washes away and you don’t replace it, the result can be “indexed steering.” This is something you don’t want.

A properly adjusted, well-lubricated headset will permit the front wheel to swing smoothly and easily from side to side, with no noticeable wobble, or “play.” To check for excessive play, just lock the front brake while rocking your bike back and forth. If the headset is very loose, you’ll hear (and feel) a distinct clunk. This is a rather undemanding test, however. To catch the trouble before it reaches the clunking stage, just cup your hand around the fork crown and repeat the lock-and-rock process. Now you’ll be able to feel even the slightest click.

And what if you do elicit a click or a clunk? What then? Easy: Take up the slack. But don’t overdo it. Too much preload on the headset bearings will shorten their life. The aforementioned “indexed steering” is one likely result. It’s pretty easy to spot, though it’s a lagging indicator of headset trouble. By the time you notice it, the damage has been done. Still, it’s something you want to know. Just lift the front wheel off the ground and swing the bars from side to side. Smooth and easy? Then you’re good to go. But if the wheel moves from one apparently preset position to the next (that’s where the “indexed” comes in), you’re overdue for a new headset.

Fair warning: Swapping out a headset is not a job for the faint of heart. See “Further Reading” below for details. But here’s a worst-case scenario for your consideration: Farwell’s stock-build Surly Long Haul Trucker arrived with a poorly bedded headset. Unfortunately, it passed all the quick-and-dirty tests. The wheel turned easily, and there was no obvious indexing. It did seem a little hard to adjust the play, however. It was either too lose or too tight. But Farwell was in a hurry to get his new bike on the road, and he ignored the warning signs, settling for a “close enough” adjustment.

This was a bad idea. The problem got worse during the first few hundred miles, and when Farwell finally acknowledged that something was seriously wrong, here’s what he found:

Notched Crown Race

Not a pretty sight, is it? The scalloped edge of the crown race exhibits a bad case of the damage commonly (if inaccurately) known as brinelling. The steerer tube was scoured, as well:

Scoured Steered Tube

It was a terminal case. The headset was ruined beyond repair. The only cure? Fitting a new headset. Which is what Farwell did.

The takeaway message? Check your headset often, and if perfect adjustment — neither too lose nor too tight — eludes you, don’t settle for good enough. Find out what’s wrong, and then put it right. Or have your local mechanic do the job for you. That’s probably the wisest course, in fact, since problems that can’t be resolved with a simple adjustment or lubrication often require replacing the headset, and this requires either specialist tools or a highly developed knack for improvisation. It’s not really a job for a rank beginner.

In other words, use your head. Keep your headset properly adjusted and lubricated. And when trouble surfaces, have it seen to without delay. That’s the only way to head off headset problems.

 



 

Further Reading

 

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May 15 2015

Photo Finish for May 15, 2015: Sumer Is Icumen In …

Canada’s upcoming Victoria Day weekend marks the quasi-official start of the summer holiday season in New York’s Borderlands. Soon the tourist tide will swell to High Water Summer levels, ebbing and flowing across the St. Lawrence in a stately dance, set to the music of humming tills. This is what Chambers of Commerce on both sides of the international border are hoping, at any rate.

Meanwhile, the earth goes about her own business, observing no calendar but that dictated by the sun. So if you’re headed south (or north) this weekend, and you plan to spend some of your time out of doors, don’t be fooled: It may be summertime in the HyperMarts, but its still spring in the hills — and spring can be mighty frosty.

Frosty Morning

 

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