Bicycle Mechanics - Busting Spokes- Need Schooled

Last spring I got cadence on my new mountain bike and immediately discovered that i was faster (more efficient) using my big chain ring most of the time. While that has made me faster, and i really enjoy it, i have also been destroying spokes like nobody's business.

I have lost count on the number of spokes i have broken since then. I know there have been at least 5 on 3 different bikes, always on the rear wheel. I've come to accept that this is the price for putting more force on the drivetrain, but it is also apparent that i am going to go broke hauling all of my wheels to the LBS.

I know there are tons of articles, on wheel truing and I am fine there. But where do i buy spokes? How do i know which spokes to get? What else do i need?

If you'll search the archives you'll find several past threads on spokes and why they break.
Basically it's the loose ones that break.
If you'll take a broken spoke to the LBS they should be able to sell you the correct replacement.
On the rear wheel the driveside spokes are shorter than the non-driveside.

Al

I recommend a truing stand, and the Park TM-1 tension meter, as well as spoke wrenches of your choice. Personally I have a Spin Doctor II Truing stand, $44 from Performance, and it works pretty good. I dont see how the extra $120 of the park ts-2 would make much difference, for a occasional wheel truing. besides, I wanted to spend the money on the tension meter so i could get my spokes all in a close range of tension.

Ive never *knock on wood* broken a spoke on any of the 7/8 bikes ive owned in my life. And some of them have been abused and ridden a lot. ive damaged spokes with the chain (fell off cassette, somehow?) but never broken a spoke.

as far as learning to do it, its MOSTLY practice and patience. You really need to understand mechanics as well.

You're big chainring should actually put less stress on the spokes. The lower the gear, the harder it is on the rear wheel. However, i don't think the gearing choice has a significant effect on spokes breaking. Well made wheels should me able to stand up to anything the drivetrain can throw at them. You should definitely look for a wheel with butted spokes, as they tend to last longer.

Mashing is not excuse for breaking spokes. You need to make sure your wheels are kept up to proper tension by checking every couple months.

Are you breaking NDS or DS spokes? If you are breaking NDS spokes, then you might re-lace the NDS radial, as suggested by Sheldon Brown (http://www.sheldonbrown.com/wheelbuild.html). If you are breaking DS spokes, then it's likely that your whole wheel is under-tensioned.

You're big chainring should actually put less stress on the spokes. The lower the gear, the harder it is on the rear wheel. However, i don't think the gearing choice has a significant effect on spokes breaking. Well made wheels should me able to stand up to anything the drivetrain can throw at them. You should definitely look for a wheel with butted spokes, as they tend to last longer.

I can't see how the larger ring would put LESS stress. On the middle ring i was spending more time spinning, putting much less force on the crank arms with each stroke. In the big ring there is a significant amount more of force exerted.

Just to put this into perspective: I rode for almost 4 years nearly daily without breaking a spoke. In the past 6 months (since switching cadence) i have broken at least 5, and had the rear wheels trued even more than that. There is absolutely no question that the cadence has caused this.

Keep in mind that i have broken spokes on three different rear wheels. I will concede that i run cheap wheels. They are all OEM from trek 4300's one trek 6000 and I also have one set of rhynolites that i have also broken a spoke on. I have broken a couple on my Open Pro's with ultegra hub.

I can't see how the larger ring would put LESS stress. On the middle ring i was spending more time spinning, putting much less force on the crank arms with each stroke. In the big ring there is a significant amount more of force exerted.

More force but correpondingly less mechanical advantage with the end result of the same torque on the rear wheel. You have to analyze the entire drive train, not just the crank.

So what is the best way to order spokes? I didn't see my inexpensive wheel/hub listed on any of the data bases linked. Do i just need to measure? Is that able to be done with spokes still installed? My LBS is small and the last time i was there they didn't even have black spokes.

Buy spokes at the LBS. They won't be much more expensive, and they can swap out for wrong sizes and such.

More force but correpondingly less mechanical advantage with the end result of the same torque on the rear wheel. You have to analyze the entire drive train, not just the crank.

Remember though, he's going faster now, which means more torque on the rear wheel.

Buy spokes at the LBS. They won't be much more expensive, and they can swap out for wrong sizes and such.

Are you kidding! Spokes at the LBS are $1 a piece. If I only need a few that's fine. But for a full wheel's worth I can get them 1/2 of that or less over the internet. Besides most local shops I've been to carry only a pack or so of each size.

I guess I'm spoiled by the LBSs in Austin, Denver, and Salt Lake City...

Where can you get DT Comps at $0.50 for a 20 ct?

Why would you purposely ride less efficiently?

Unless you are touching 30 mph you dont need to be anywhere near the big ring.

Lane Armstrong is probably twice as powerful as you and yet I would guess his cadence is probably 50 rpm higher based upon what you are saying.

The big chainring is a place for newbies to hang around. You rarely see an experienced cyclists under 85 rpms. 85 rpm's on the big chainring is above 30 mph. I know you arent averaging 30 mph unless you are lance armstrong and Im just confused.

It is late. : )

... 85 rpm's on the big chainring is above 30 mph....and Im just confused...It is late. : )

True dat.
with 700x23 tires, 52 big ring, 14 cog, 30mph = 103rpm.
At 85 rpm ~ 25mph.
I guess you just don't like to ride in all those big cogs above 12 :)

Why would you purposely ride less efficiently?

Unless you are touching 30 mph you dont need to be anywhere near the big ring.

Lane Armstrong is probably twice as powerful as you and yet I would guess his cadence is probably 50 rpm higher based upon what you are saying.

The big chainring is a place for newbies to hang around. You rarely see an experienced cyclists under 85 rpms. 85 rpm's on the big chainring is above 30 mph. I know you arent averaging 30 mph unless you are lance armstrong and Im just confused.

It is late. : )

When you wake up, you're really going to laugh at your post ;)

ok, ok,

I guess my cadence is higher than I realize. I never touch the big ring unless Im going well over 30 on my mountain bike style bike.

sorry. I will slink off into the morning sun now.

ok, ok,

I guess my cadence is higher than I realize. I never touch the big ring unless Im going well over 30 on my mountain bike style bike.

sorry. I will slink off into the morning sun now.

Yeah, I'm in the 95-105 rpm range if I'm not climbing, and I'm in the big ring most of the time, in a 19t or 17t cog. I wouldn't call myself a masher, but I'm not an extreme spinner either.

hey waterrockets, what LBS in Austin is going to have 50 cent spokes? last time I had to buy a spoke they ripped me for two bucks for a Mavic straight-pull 14ga spoke. Now I would like to buy two wheel's worth of these spokes but you had better bet I'm not going to cough up $100 for them. so tell me where to go get spokes (I need straight pull spokes for a Mavic wheel) in Austin and I'll gladly go and pay 50 cents each for them and even buy an entire box of 50 or even 100 if I must.

BTW my other topic on this forum about these Mavic spokes has gone unanswered. I think that's kind of funny considering how popular Mavic wheels are ... certainly someone has figured out where to get replacement spokes ... does DT or Wheelsmith make replacements for the Mavic wheels? Not that I can tell.

ok, ok,

I guess my cadence is higher than I realize. I never touch the big ring unless Im going well over 30 on my mountain bike style bike.

sorry. I will slink off into the morning sun now.

I guess we can forget your posts, because obviously using the big ring does not automatically = 30 mph. For me I had to move to the big ring on my mountain bikes because my cadence was WAY higher and much less efficient, when i was on the middle ring.

Regardless, through it all, i still don't know how to measure and order spokes. The nearest i can gell is you measure for the elbow of the spoke to the tip in mm and then order?

that's how you measure it!

if it's a 2mm spoke (14g) then you may be off by as much as a mm, but that won't make much difference unless the spoke was already way off of the right length to begin with.

go to sheldonbrown.com and read all about wheel building, spokes, lengths, you name it, you can learn it on that web site. you'll be better off doing that than hanging out hoping someone will tell you how to do it on this forum.

that's how you measure it!

if it's a 2mm spoke (14g) then you may be off by as much as a mm, but that won't make much difference unless the spoke was already way off of the right length to begin with.

go to sheldonbrown.com and read all about wheel building, spokes, lengths, you name it, you can learn it on that web site. you'll be better off doing that than hanging out hoping someone will tell you how to do it on this forum.


Sheldon's site is very helpful and wheel-building/truing have been covered to death here. Do a search or at least read this http://www.bikeforums.net/showthread.php?t=338432 There is a ton of info out there.

These wheels you have gone through spokes on are all relatively inexpensive, machine built wheels. There is nothing wrong with that but they routinely have low or imbalanced spoke tension. Spokes in the wheel that have endured some stress as a result will look fine now and "pop" at a later date. rebuild with proper tension and they will be fine. If you buy new, have them tensioned properly right away. That way you can avoid this in the future.

hey waterrockets, what LBS in Austin is going to have 50 cent spokes?

Sorry if my post read that way. The other poster was saying that LBS spokes are $1, and he can get them online for half that (which is $0.50), so I was wondering where.

Here in Austin, I think they are around $0.75 with bras nips, which I don't think is that big of a deal. It's been a while, but I think that's what I paid last time. Not a bad price if there's a chance your spoke calcs are off.

I just paid $0.75 each for Wheelsmith with brass nips a week ago here in Michigan.

Remember though, he's going faster now, which means more torque on the rear wheel.

Considering that, according to Jobst Brandt's analysis, spokes are approximately 3 times stronger than the maximum load seen, and that loads from bumps in the road are far greater than those due to pedaling, I would have to say that if the spokes are breaking from the OPs increased speed, then his wheels are in very poor condition constantly on the edge of failure and simply need to be rebuilt using new spokes.

Although I don't know the OP, I suspect that he does not approach the pedal forces of an elite sprinter, and they aren't busting spokes coming to the line.

I guess we can forget your posts, because obviously using the big ring does not automatically = 30 mph. For me I had to move to the big ring on my mountain bikes because my cadence was WAY higher and much less efficient, when i was on the middle ring.

Regardless, through it all, i still don't know how to measure and order spokes. The nearest i can gell is you measure for the elbow of the spoke to the tip in mm and then order?


I dont want to argue but what is your cadence?

Forget it. I really dont feel like arguing.

Have a good one everybody!

Forget it. I really dont feel like arguing.

Have a good one everybody!


Nothing to arue about. My cadence is now lower than it used to be. I used to ALWAYS run on the middle ring of a triple and spin faster. I try and keep cadence around 90 on road bike and presume about the same on mtb's although i have no cadence on them.

The end result was I got faster, there is NO question about this. You can question whether this caused more spokes to break or not, that is fine. I am inclined to believe this is the cause, based on the thousands of hours i have spent on the bike and the observations that have been made.

Considering that, according to Jobst Brandt's analysis, spokes are approximately 3 times stronger than the maximum load seen, and that loads from bumps in the road are far greater than those due to pedaling, I would have to say that if the spokes are breaking from the OPs increased speed, then his wheels are in very poor condition constantly on the edge of failure and simply need to be rebuilt using new spokes.

Although I don't know the OP, I suspect that he does not approach the pedal forces of an elite sprinter, and they aren't busting spokes coming to the line.

I agree. With a good wheel, you should be able to double the power load and see virtually no change in durability. I don't think any of the wheels we're talking about are properly built, and he is putting out more power now, so it could be the last straw...

well 75 cents is a far way off from $2 for a spoke. But I figure if I am going to buy a whole box, maybe they should give me a break?

I look at it this way: when I go into a bike shop and they overcharge me by a factor of 3 or 4 for one 50 cent item, then it leaves a bad taste in my mouth for the shop and they will give up all of my business on more expensive stuff. I know many bike shops seem to think that since their cost of labor and inventory for small items like spokes is so high, it's ok to overcharge for them. But I can say definitively that if they are willing to give away a spoke or two as a part of the cost of retaining customers, they have a lot more money to be made by selling bikes and wheel sets down the road when they have fostered good will with their customers.

This is why bike shops have such a hard time staying in business. They don't understand customer retention.