delbiker1 

I was 2 miles into my rides this morning when a spoke broke on the rear wheel, 2 year old Fulcrum Racing 5. I had never before broken a spoke while riding. I had to walk the bike home and take a different bike. I am going to have to do some research as I have never replaced a broken spoke before. Any hints/tips from anyone, video's to watch?

Retro Grouch 

See if you can come up with a theory why the spoke broke. Sometimes the spokes have different tensions, sometimes the whole wheel seems under tensioned, sometimes a group of spokes have chain damage. Sometimes I can't find a cause.

I'm a believer in retrueing and retensioning the entire wheel when replacing a broken spoke.

BikingViking793 

this seems like good advice. I break a lot of spokes. Current wheels on my road bike went 2 years no breaks. Now I’ve had 2 in last year. If I have time I’ll better look at whole wheel. Won’t be surprised if another breaks in the mean time.

alo

You can normally ride home a bike with one broken spoke. Obviously you need to replace it.

delbiker1 

Alo, the wheel was so out of true after the spoke popped, there was no way I could have ridden it home. I had just stood on the pedals to kick up the speed when it the spoke broke. I had to open the brake calipers to be able to walk the bike. The spoke is drive side and broke right where it connects to the hub.

andrewclaus

Have you ever shifted the chain into the spokes? If so, replace all the outward-facing spokes on that side (1/4 of the wheel).

Those are your tightest spokes and breaking those is most common. You'll also have to remove the cassette to change the spoke. And remove another spoke on the same side of the wheel to get the right size. The rear wheel is dished and and probably has two different length spokes, both of which may be different from the front.

If you have double wall rims, be careful not to drop the nipple into the rim. You can use another spoke threaded into the "back" side of the nipple to hold onto it.

Some folks have disk brakes and can usually ride okay with a broken spoke, but having rim brakes could make that dangerous.

Loosening and retensioning all the spokes is certainly the best way, but this may not be a good time to learn how to tension a wheel and gather the tools. You should be okay if you add a spoke and true it. If you break another one soon, you'll know the wheel needs more work.

adipe

residual torsional stress on drive side spokes... and uneven tension. therefore fatigue. damage on the surface of the spokes can also contribute.


6:00 spoke momentarily loses some tension, 7:30 and 5:30 spokes have more tension under dynamic loads.

davidad

I hope you are a light weight. 20 spoke wheels are not going to be known for longevity.

jimc101

? I have used Fulcrum 5 & 7 wheels for years as on a commuter, wore the rims out of a few rears, never had any issues with spokes. Fulcrum 5's are reasonably light weight, but not that light weight as wheels go.

davidad

How much do you weigh?

joejack951

#1 tip: if you broke a spoke after only 2 years, you have a bigger problem than just that one broken spoke.

Go over the entire wheel with a tension meter and get the tension high enough on the DS (110-120 kgf) to ensure the NDS spokes aren't going slack. You want the NDS at 60 kgf or higher in my experience. In order to avoid windup on the DS spokes when tensioning that high you will want to grease/lube the threads and nipples. If you aren't keen on a complete disassembly to add grease, some chain lube dripped on each nipple will usually suffice.

You still may break some spokes so you'll have to decide if it's worth replacing them all now or waiting and replacing as they break. I've done it both ways and usually regret skipping the full replacement.

delbiker1 

Thanks to all that have responded. First off, I am 155 lbs. and much more of a spinner than a masher. At least 95% of my riding is on paved roads that mostly are in good shape. Also, it is very flat and most of my miles are in a more rural type area. Ergo, not all that much shifting and braking. I looked at all the spokes and can see no visual evidence of damage, but, there is a chance that I ran the derailleur into the spokes while working on the bike at some point. I have not checked the tension of the remaining spokes, but will probably do that today.

I have never had a problem with wheels unless or until I get a lot of miles on them, or I run over a significant hazard of some kind. I rarely even have to true a wheel. All the suggestions that have been posted make sense and are helpful. After checking the tension on all the spokes, I will then decide what to do to get the wheel back on the road. Fortunately, this does not stop me from riding, or even riding that bike. I have 6 other bikes to choose from, and a few sets of wheels that are not in use at this time.

davidad

Not on a 20 spoke spoke wheel.

davidad

On a 20 spoke wheel the drive side needs to be at least 130 maybe 140kG tension.

bktourer1

One of these can be helpful. Used one to temp fix a friend's bike

FIBERFIX Emergency Spoke Replacement Kit

jimc101

At the time using them, between 85-90kg (say 190lbs) with about 5kg (10lbs) in pannier, so no light weight!

joejack951

That's getting into cracked rim territory so I'd consult with the manufacturer before going that high. At 155 lbs. I personally don't see that as necessary but YMMV.

I tried to find Fulcrum's spoke tension spec but they do not list that info online. I did find their user manual: https://www.fulcrumwheels.com/area/d...&rndc=1&rnts=1

...which has something interesting tidbits, most curiously the recommendation to have spoke tension checked MONTHLY. Geez, not quite sure what to make of that. At least you are under 180 lbs. otherwise they want you to be even more vigilant

coffeesnob

you need to see if the spoke broke by fatigue or overload.

davidad

A friend had Trek Rolf and Bontrager low spoke count wheels. Back then Trek was more open about info about repairing their products. On 24 spoke wheels they recommended 130 kG tension on the drive side spokes. They had a jig for the dealers that allowed the hub to be pushed toward the spokes being tensioned so that it would be easier to turn the nipples.

davidad

Spokes don't break because of overload unless something goes between them and the frame or fork.

coffeesnob

ya I know that. but you could over tighten it couldn't you?

davidad

Trust me, it isn't gonna happen. Load it to about 480 pounds and the spoke will break. Course the rim will have collapsed long before.

delbiker1 

I took another look at the spokes on the wheel. Again, I can see no visual, nor can I feel any evidence of spoke damage. I got tied up and have not checked the spoke tension. I can report that the spoke broke right at the ball type end where it connects into the hub. It seems to me, that indicates a problem with tension and/or fatigue. I hope to have some time tomorrow to get into it a bit more in depth.

coffeesnob

probably fatigue