popped a spoke today.....

BoydD

....made a hell of a noise, thought the frame had cracked at first but on closer inspection I found a broken spoke. It had broken near the hub and caused the wheel to be so untrue it rubbed the brake.

I'd just completed around 30 miles and luckily I was only a mile from home when this happened, with the wheel so untrue it would have been diffucult further from home. Could I have done anything to make the wheel useable if I was further from home?

Anyway, bike is only 9 weeks or so old and due a complimentary service from the LBS so I called them and they offered to sort the wheel while they do the service. Nice gesture from them so I dropped it off so I'm bikeless for the next few days...

When I dropped the bike off the chap checked the chain wear and said I was near needed a new one. I have hammered the bike a little and probably done around a thousand miles on this chain. Does this sound right? Am I doing anything wrong? I know about cross chaining and I rarely run from big to little or vice versa.

desweller

Wear a chain out in two months? He's taking the mick.

sungod

is this a new bike?

if it is, the the shop should certainly fix for free

unless it was damaged by something, it's possible it snapped because the wheel was poorly built (spokes not tensioned correctly, not uncommon)

they should replace the adjacent spokes as well, and check/adjust the whole wheel (the spokes next to the broken one will have been heavily loaded, unless replaced they are much more likely to fail)

a chain should last a lot longer than 1000 miles!

imho check it yourself - http://bicycletutor.com/chain-wear/

BoydD

thanks for the replies,

is this a new bike?

yes, and in fairness to the shop they are fixing it for free.

Wear a chain out in two months? He's taking the mick.

he wasn't on the hard sell or anything, measured with a wear indicator with colour coded rollers , mine was near the red. I must admit, I was a little surprised that it appeared so worn.

Speedmenace

i've never had a spoke snap on me before, seems a strange thing to happen

desweller

I'm not a big fan of chain checkers, I have to admit. I'd rather just use a ruler! If you've not been oiling the chain I suppose it could wear out pretty quickly; not sure I'd like to be the one to try to quantify it though.

As for the wheel, you should be aware that a failed spoke is usually the sign of a poor initial build; chances are that you have other spokes that have gone into yield and will soon break. If you get another breakage after the shop has replaced the existing broken spoke, you should insist on a full rebuild with new spokes.

cougie

Spokes do break. It's not a biggie.

unixnerd

Could I have done anything to make the wheel useable if I was further from home?

Brake callipers have a knob near where the cable joins, if you rotate it they open up a good bit. It's there to make removing a wheel easier as large tyres won't pass the brakes. If the wheel is damaged you can open the caliper up this way and rely on the other brake.

balthazar

sungod wrote:

they should replace the adjacent spokes as well, and check/adjust the whole wheel (the spokes next to the broken one will have been heavily loaded, unless replaced they are much more likely to fail)

That is a common misunderstanding. However, spokes are most highly tensioned at rest: their tension only decreases in use. After a spoke failure, other spokes are unaffected (though the wheel as a whole is weakened).

Nonetheless, it's possible that wheels are assembled from poor batches of spokes, or that the wheel is poorly built without any kind of stress-relieving, and that other failures will follow. In those cases, a rebuild may be advised, potentially with new spokes. I wouldn't consider this until a few spokes have failed, however: the odd spoke does fail, even in the best of circumstances.

OP: It's quite possible to wear a chain out in a few hundred miles, if it's been ridden in wet, gritty conditions, but the gizmo the mechanic is using won't reveal it. Measure the chain with a ruler, per Sungod's link: that is decisive.

I think it's a considerable problem of low spoke count wheels, that a single failure can make a bike unrideable. I'd always choose enough spokes that a single failure is an inconvenience at most.

sungod

balthazar wrote:

That is a common misunderstanding. However, spokes are most highly tensioned at rest: their tension only decreases in use. After a spoke failure, other spokes are unaffected (though the wheel as a whole is weakened)
<..>

the point is that on low spoke count wheels, the tension on the adjacent spokes goes way up - i measured mine out of interest after popping a spoke last year

not trying to start an argument, life's too short, but lots of people report the adjacent spokes failing after only a single spoke is replaced, what do you reckon causes it? the effect of the higher load/unload forces from riding home on the wheel, or just cack-handed work in the shop?

balthazar

sungod wrote:

balthazar wrote:

not trying to start an argument, life's too short, but lots of people report the adjacent spokes failing after only a single spoke is replaced, what do you reckon causes it? the effect of the higher load/unload forces from riding home on the wheel, or just cack-handed work in the shop?

Bear in mind, when visualising this, that a spoke failure is the final event in a very much longer process: the crack has been growing for thousands of cycles, at least; the spoke was broken nearly totally through at the start of the ride. Understanding that, I think it becomes obvious that other spokes will have been suffering the same way, and that other breakages will follow.

Fatigue cracks in spokes are nearly invisible, hence the tendency for people to attribute the cause of failure to the last pothole or whatever – whereas the spoke may in fact have been broken for months.

The point is, all the failures share a root cause, and are not caused by one another.

I cannot imagine a wheel in which tension of one spoke increases as another is removed?! In all ordinary bicycle wheels, the reverse is the case, regardless of spoke number.

BoydD

Again, thank you for your replies,

I think it's a considerable problem of low spoke count wheels, that a single failure can make a bike unrideable. I'd always choose enough spokes that a single failure is an inconvenience at most.

my wheels are pretty standard in terms of spoke count, they are the standard wheels supplied on the Cannondale Synapse Sora: Maddux 3.0, pretty standard cheap factory wheels really. When the spoke went the buckle on the wheel was so significant that even with the release raised on the brake caliper it rubbed. It had around and inch and a half movement, across and back.

I'll check with the shop that they have checked the other spokes, although I assume they'll have to do this to true it up again.

OP: It's quite possible to wear a chain out in a few hundred miles, if it's been ridden in wet, gritty conditions, but the gizmo the mechanic is using won't reveal it. Measure the chain with a ruler, per Sungod's link: that is decisive.

I am guilty of riding in the wet, in fact I really enjoy it. I do lube the chain with wet finish line regualrly but I do ride in all conditions. This could be a factor. When I get the bike back I'll check the chain using the ruler method.