3 spokes and out?

[Nick G]

My LBS, who I trust, has a rule. On the third broken spoke within a matter of weeks he replaces the wheel. From a practical perspective this makes sense, but what is the thinking behind it? In what way do wheels fail so that spokes pop regularly?

Related to this, I still have the old wheel. I assume the rim is no good anymore although the spoke pops at the hub. Could it be that the hub is not worth keeping in the shed either? If it is I'll dismantle the wheel, but if not I'll chuck the whole thing.

If it helps to advise on whether to keep the hub, it's c1990 off a Marin Sausalito 7 speed freehub.

Thanks for your thoughts.

 

[marinyork]

3! Think my back wheel has had 11 spokes replaced, might even be 15 I've lost count. LBS says it is now new wheel time but give it some hammer over the winter and replace in the spring.

 

[fossyant]

Just badly built with cheap spokes and uneven tension.....

 

[marinyork]

Just badly built with cheap spokes and uneven tension.....

That's probably true but the tension meters I've looked into are more money than the wheel itself.

 

[Smokin Joe]

That's probably true but the tension meters I've looked into are more money than the wheel itself.

I'd either learn to do it yourself or find a LBS who know what they are doing. As fossyant said, crap build quality is the reason spokes break.

 

[Twenty Inch]

My LBS, who I trust, has a rule. On the third broken spoke within a matter of weeks he replaces the wheel. From a practical perspective this makes sense, but what is the thinking behind it? In what way do wheels fail so that spokes pop regularly?

Related to this, I still have the old wheel. I assume the rim is no good anymore although the spoke pops at the hub. Could it be that the hub is not worth keeping in the shed either? If it is I'll dismantle the wheel, but if not I'll chuck the whole thing.

If it helps to advise on whether to keep the hub, it's c1990 off a Marin Sausalito 7 speed freehub.

Thanks for your thoughts.

The LBS is having a laugh.

Spokes fail because the tension loosens off. This means that they move around relative to hub and rim with every revolution of the wheel, alternately being pulled tight and then compressed soft. This eventually gets so severe that that the spoke head lets go and the spoke breaks. It's more common on the drive side of back wheels, as that's where most tension is.

To prevent it, check spoke tension regularly, and keep the wheel nice and straight. If you don't know how to do this, borrow a book from a library or ask a mate.

The rim is probably still fine, the hub almost certainly is.

Now, back to the LBS. Their "rule" serves only their interests. A good LBS will rebuild your wheel. Costs of this can vary from £35-£45, incl. spokes. However it's a painstaking and exact task. Your LBS developed their "rule" cos it's quicker, easier, and more profitable for them to throw a new wheel on a bike than to strip down an old one and rebuild it.

FWIW, my local LBS rebuilt my fixie rear wheel for £30 (mates' rates) including spokes, and serviced the hub and cleaned the wheel up at the same time.

 

[Nick G]

Thanks for this. In defence of the LBS, it's not a particularly high quality wheel. But since I still have it, I'll take it somewhere else and ask them to rebuild it.

 

[Steve Austin]

I don't think its that bad a rule. What i think it means if it a few spokes go then chances are then the rest are possibly going to go soon.

IME its quite common whena few spokes break that a few more go quite soon after. I've bought and used cheap wheels like this.

 

[RedBike]

I think the rules correct.
Once one or two spokes have gone then it's normally not long before another follows. At this point the if you want a reliable wheel then it needs re-building.

The trouble is to re-build a cheap wheel often isn't cost effective.

Get a new spoke put in the wheel and use it on the turbo trainer / the pub bike. If you're covering any distance on the bike then it's time for a new wheel.

 

[andrew_s]

I concur
If you've had 3 or 4 spokes go over a few weeks (rather than 18-24 months), then the others are almost certainly on the way out. It's a new wheel or a rebuild with a complete new set of spokes, otherwise you are just going to be back in the bike shop every couple of weeks with yet another broken spoke.
As stated, it's fatigue at the bend by the spoke head, where the tension comes on and off as the spokes pass the bottom and wiggles the heads back and forth, if insufficiently tight. Spoke tension should be higher than the weight the wheel is going to support, so they don't go slack when at the bottom, and the spokes should be properly bedded in by giving pairs of spokes a very strong squeeze (gloves probably required).

 

[Nick G]

As stated, it's fatigue at the bend by the spoke head, where the tension comes on and off as the spokes pass the bottom and wiggles the heads back and forth, if insufficiently tight. Spoke tension should be higher than the weight the wheel is going to support, so they don't go slack when at the bottom, and the spokes should be properly bedded in by giving pairs of spokes a very strong squeeze (gloves probably required).

thanks, as I said, the wheel was pretty old and fairly basic Araya rims. I think I'll dismantle it and hold on to the hub which doesn't take up much space. There seems no point in rebuilding the wheel unless I decided to keep it in order to learn how to build wheels for myself, which I don't intend to do.

 

[Tim Bennet.]

This is definitely a wheel quality or build issue. The expectation of even a 'reasonable' quality wheel should be no spoke breakages in its life time, even if you're camping touring, cross country riding or hammering the Paris Roubaix cyclo.

The technology and art of wheel building has been refined over the past 100+ years to the point of perfection. Decent wheel builders can do it right, time after time after time. The advice you got from your LBS would suggest they are not one of them.

 

[jimboalee]

+1 on Tim Bennet again.

I've been wheel building for ten or so years now, and as long as I buy DT Swiss D/B of the correct gauges for the bike's purpose, I've never had a broken spoke.

Additionally, I tend to tension in the lower half of the range.

I bought my son a used MTB out the paper, and the first thing I did was relace with aforementioned spokes.