Why do I keep breaking spokes?
 

I recently bought a 2013 District S Trek a little over 6 months ago. Everything has been great, it's a beautiful & fast bike. A little over a month ago I broke one spoke, being somewhat new to the single speed bike style I kept riding, but I taped the spoke to another (I know, I'm a newbie). This lead to 3 other spokes breaking so I took my bike to the LBS, they replaced the broken spokes. I thought the original spoke broke from dropping the bike or something, and the broken spoke led to others breaking, so I thought no big deal. Then, a couple of weeks ago I broke two more spokes! Returning to the shop again, I asked the owner if I had a defect rim to which he replied I'm breaking spokes because it's a single speed. That is a satisfactory answer. He gave me some pointers on how to ride, don't jump curbs, be gentle and gradually get up to speed before you really start moving. Okay, so I have been riding that way, for the most part and obviously not "jumping curves" with a road bike. Last night riding home from work, I heard a popping sound and realized that I broke another spoke, when I got home I checked and saw that two spokes had broken! This is all in the rear wheel. Not only is this costly to keep going back to the shop because I don't have the knowledge or resources on how to re-thread a spoke, but it's also annoying and destroying my riding time. I use my bike for fitness and commute. I weigh 210 - 220 lbs (losing weight though, would like to get back to 185 lbs), and usually have a bag on me but that just has shoes and a pair of clothes so maybe 7 lbs, tops. I am not new to biking, just single speed road biking. I've used a mountain bike or BMX over the last 15 years (I'm 22). Could this be a defect rim? Am I too heavy at 220 lbs (which isn't an unhealthy 220, since I am fit...)? I just need to know if I should by a new rim all together and if the shop I bought my bike from should compensate ($$$) to some degree. I've emailed Trek, but they take so long to get back to me. I live in Florida, if that helps (I've heard heat is terrible to spokes). Thanks in advance, any help or comments is appreciated.

According to Trek's website, your wheels have 32 spokes. That number should be enough to hold your weight - even at 220#. (I started cycling at 230# and have yet to break a spoke). Breaking spokes just because your bike is a single speed doesn't make any sense. Heat shouldn't have an effect, either. My guess is that you have a defective wheel. Suggest that if your dealer is of no help, contact Trek directly - here's their phone #(920) 478-2191 - it's the main corporate number. And, take your business to a different bike shop.

That wheel doesn't sound like it was ever finished trued and tensioned properly. Sounds like to me that it was an 80 percent finished wheel when it came to the bike shop and they just let it go out the door with low tension. Low tension leads to popping spokes on bigger/stronger riders. Once 3 or so spokes pop on a wheel and if it is not fully properly tensioned after repair, the other spokes are probably weakened to the point that they will pop as well.

I would get a new wheel if you can get one under warranty or rebuild the entire wheel with all new spokes and get it properly tensioned.

I had a wheel that popped 4 spokes that had low tension and I rebuilt it completely and haven't had a single problem with it since then.

Its all about proper high tensioned spokes for larger/stronger riders.

Being single speed should mean nothing to the durability of a wheel.

^ probably. Where are the spokes breaking?

The most common cause of broken spokes is low spoke tension on the non-driveside rear wheel. The hub flanges on the rear wheel are asymmetrical to make room for the rear sprockets (s) and chain (but this should be less of a problem on a single speed). As others have said, most likely the wheel was not properly tensioned and trued. The rim did not cause the spokes to break, and neither did the heat. It's also possible that the spokes used on your wheel were not top quality. The rear wheel carries a much greater share of the weight, but your wheel should be able to carry your weight easily.

Given that its a single speed, you should actually have less of an issue with broken spokes. Less dish=stronger wheel. I've never had an issue with broken spokes, mostly because I weigh 120 lbs. I think if I did I'd have to be on an 11 speed wheel with a fully loaded touring setup. Even then I'd have to be kind of rough to break one. I would suggest just tossing the wheel and buying a 36 spoke double wall rim. It may be tough to find one for a single speed in which case you should find a professional wheel builder or make your own. That will probably be cheaper than replacing spoke after spoke.

Lot's of things could account for broken spokes, from weight and riding style, to poor hardware, to poor wheelbuilding.

Some people are very married to their theory, and will always blame a single cause. But IME I've seen gorillas (pro football players) who rode like ballerinas, and at least one ballerinas that was harder on wheels than any gorilla I've ever met.

All things being equal, a fixed gear wheel will be stronger than a derailleur bike wheel, because the flanges are farther apart (always helps), and there's less tension difference between the right and left sides. Also bike factory wheels tend to be shorter lived than hand built after market wheels because of differences in hardware (plain gauge spokes vs butted for example, less concern for uniform tension, failure to effectively stress relieve the spokes, and other minor things that separate a well built product from a mass produced product.

Without actually seeing your wheel, and knowing how you ride, I can't pinpoint any one actual cause (only a mechanically knowledgeable psychic can), but given how many spokes have broken, I'd say it's time to rebuild fresh.

The one part least likely to be a cause is the rim, and also the hub, so it's probably safe to reuse both if they check out in good shape. For a stronger stiffer wheel, you might go to a wider, deeper rim, but without knowing more, I can't say whether it's necessary.

Where are the spokes breaking?
Bend, nipple, other?

Which side? DS or NDS?

How many times have you Been back for a maintenance wheel truing session at the Bike Shop. ?

Contact your dealer. Trek will happily replace the entire wheel. I know this because I am a Trek dealer. :-)

Do you understand what dish is?

=8-)

I hope so. There is less dish on a single speed wheel which makes it stronger overall yes?

http://www.bikeforums.net/showthread...ing-here/page2

Post #30 .

Any wheel that does not have adequate tension AND is not properly stress relieved is going to suffer from spoke failure sooner rather than later. Doesn't matter if it is a multi-speed or single-speed wheel - symmetrical or asymmetrical in it's "appearance" form of dish.

As to strength - an offset of 34.5 ( most symmetrical front hubs ) and 32.5 ( most asymmetrical rear NDS ) will provide more lateral strength than 16-22.0 ( most front disc side and rear drive side offsets ).

Note I used the word "offset". That's what is really driving what you see when describing dish as an "appearance" as opposed to dish as a "verb" - centering the rim between the hub lock nuts.

So of course - less "offset" generally means less "lateral strength".

=8-)

Well I was assuming a properly tensioned and relieved wheel. But thanks for the lesson :)

While Mr. Rabbit is very adamant about the definition and use of the word dish as applied to wheels, it's use varies, possibly by region, or by age.

Dished (asymmetric or offset) rear wheels are a relatively new thing. Prior to the sixties wheels were typically symmetrical, both front and rear. With the advent of asymmetrical rears because of 5s freewheels, we started applying the adjective dished to describe these. We never spoke of front wheels as being dished, it was reserved for asymmetric rears.

For many of us greybeards, dished still applies only to asymmetrical wheels, now including disc front wheels. We'll also use the verb form to mean to move the entire rim in one direction such as to bring it from centered in the flanges to being centered in the axle.

So, while different speakers may use the words dish or dished differently, the meaning can usually be taken from the context, something it has in common with many (most?) words in the English language.

Sheldon Brown and Tulio Campagnolo were never "greybeards"?

As my signature indicates - I don't own nor am I the originator of the two different terms, types and descriptions of "dish" as they apply to bicycles. They existed before I arrived on the scene in 1984.

=8-)

Tulio was a generation older than me, Sheldon roughly the same age. If you read SB texts, you'll see examples of usage of the word dish in various forms, with the meaning being clear by context.

While you claim not to own the words, you do fee free to "correct" those who use the terms differently that you would. I posted only to show that the terms are used loosely by many and folks needn't feel confined to narrow usage a long as they understood the concept, and that their meaning was clear by context.

Yes, the term was coined, reflecting the dish shape of wheels, but langiage evolves, and multiple uses are equally correct.

1. non-sequitor (earlier post)

It goes without saying that folks elsewhere in the world may have different terms for the same two concepts.


2. strawman

My purpose is not to dictate what terms people use - it's to make certain that folks understand there's TWO types - and that folks assisting others need to be careful to not CONFLATE the two.

If someone is asking, "When I'm truing up my wheel, what does it mean to dish the wheel?" The most helpful and straightforward response is to discuss that dishing related to centering the rim between the lock nuts of the hub.

I've been crystal clear on this in repeated threads...

...and of course, Sheldon Brown discusses both - and Tulio Campagnolo was crystal clear on what the purpose of his dishing tool was in the advertisement.

But then again - that's a non-sequitor on my part...

=8-)

I was simply pointing out that Jowilson's posts were clear, and didn't need correction, and that from his response to your "Do you understand what dish is?" showed that he understood the concept, though maybe your narrow use of the term.

I don't recall him asking for help...

I checked him - he responded quite well on my check - even finished with a smiley.

...something I should do more often really.

=8-)