Breaking spokes - AGAIN!!!

[OldBull]

Hi all

 

Thanx for all the great advise. I now understand the spoke issue better.

 

Spoke to the wheel expert at a new LBS. Heard good things about them. They showed me that one of my spokes got damaged and was bent badly. This might have caused additional tension on the other spokes and that is why they snapped.

 

He is busy going through the whole wheel and said he may have to replace about half of them.

 

Rims are WTB STP Rims with 32 spokes. For now I am going to go with this mini re-build, but will start putting money aside for a future 36 spoke wheel.

[Lance Stephenson]

Hi all

 

Thanx for all the great advise. I now understand the spoke issue better.

 

Spoke to the wheel expert at a new LBS. Heard good things about them. They showed me that one of my spokes got damaged and was bent badly. This might have caused additional tension on the other spokes and that is why they snapped.

 

He is busy going through the whole wheel and said he may have to replace about half of them.

 

Rims are WTB STP Rims with 32 spokes. For now I am going to go with this mini re-build, but will start putting money aside for a future 36 spoke wheel.

Hi

 

As a master wheelbuilder I can tell you that there are many factors that cause spokes to break.  Where they break is important as it tells a story of why.  Rim choice IS important because If you are a heavy rider or an aggressive one, the softer Ultra lightweight rims deform at the bottom ( like a tyre that is under inflated) and this causes the spokes to go through a tension/detension cycle with every revolution.  This can cause the spokes to break at the elbow (where it bends and terminates from the hub).  This movement can also cause thicker spokes not to snap but allow the nipples to turn loose over time (of the wheel is not built with some version of spoke thread prep).  Incorrect tensions also have a part to play in all this.  When building a wheel, the drive and non-drive side spokes would be around 20% different in tension to each other (because of the dishing) and the spokes on the same side should be within 3% average difference of each other.  When a rider with a correct rim for his weight and or style snaps spokes (more than 3 in a space of a month) I scrap all the spokes and start again.  It's the only way to ensure a good repair, it may seem like an expensive solution, but it's actually the cheapest.  Imagine having to keep going back every week and having the downtime PLUS the disappointment.  I would recommend against replacing half the spokes generally speaking.  If your spokes are bent, you have to ask why and correct that issue!  Derailleur hangars that are bent or derailleur limit screws that are set poorly that cause them to fall into the spokes is a common one.  A bike that falls over to the derailleur side can bend the derailleur hangar enough for this.  Check this!  Good luck.

[OldBull]

Hi

 

As a master wheelbuilder I can tell you that there are many factors that cause spokes to break.  Where they break is important as it tells a story of why.  Rim choice IS important because If you are a heavy rider or an aggressive one, the softer Ultra lightweight rims deform at the bottom ( like a tyre that is under inflated) and this causes the spokes to go through a tension/detension cycle with every revolution.  This can cause the spokes to break at the elbow (where it bends and terminates from the hub).  This movement can also cause thicker spokes not to snap but allow the nipples to turn loose over time (of the wheel is not built with some version of spoke thread prep).  Incorrect tensions also have a part to play in all this.  When building a wheel, the drive and non-drive side spokes would be around 20% different in tension to each other (because of the dishing) and the spokes on the same side should be within 3% average difference of each other.  When a rider with a correct rim for his weight and or style snaps spokes (more than 3 in a space of a month) I scrap all the spokes and start again.  It's the only way to ensure a good repair, it may seem like an expensive solution, but it's actually the cheapest.  Imagine having to keep going back every week and having the downtime PLUS the disappointment.  I would recommend against replacing half the spokes generally speaking.  If your spokes are bent, you have to ask why and correct that issue!  Derailleur hangars that are bent or derailleur limit screws that are set poorly that cause them to fall into the spokes is a common one.  A bike that falls over to the derailleur side can bend the derailleur hangar enough for this.  Check this!  Good luck.

Hey Wow thanx Lance.

 

You are a bit too far so I cannot use your services, a real pity. Just for info, it seems as if the bent spoke was hit by a stone. Think I will have to change the way I look at this.

[Hairy]

Hi all

 

Thanx for all the great advise. I now understand the spoke issue better.

 

Spoke to the wheel expert at a new LBS. Heard good things about them. They showed me that one of my spokes got damaged and was bent badly. This might have caused additional tension on the other spokes and that is why they snapped.

 

He is busy going through the whole wheel and said he may have to replace about half of them.

 

Rims are WTB STP Rims with 32 spokes. For now I am going to go with this mini re-build, but will start putting money aside for a future 36 spoke wheel.

Replace all the spokes.

 

I had a set of wheels a few years back that had the same issues, you break a spoke, it gets replace....a few rides (A few if you are lucky) later and you have a broken spoke again.

 

Had a really good wheel builder re-build the wheel with new spokes and brass nipples.........never broke a spoke again after this, and the wheel certainly felt better when accelerating.

 

Good wheel builder + good spokes / rim combo = happy rider 

[V12man]

Hey Wow thanx Lance.

 

You are a bit too far so I cannot use your services, a real pity. Just for info, it seems as if the bent spoke was hit by a stone. Think I will have to change the way I look at this.

Don't replace half the spokes - replace ALL of them and the nipples - and find a wheelbuilder that recommends that as the solution - then once the wheel is built and has a few hundred km on it, get it retensioned properly again - perhaps it's worth an annual retension as well at your weight - maybe even more often - once they start to lose tension/are unevenly tensioned for whatever reason, then they start to break....

 

Still - replacing half the spokes is a recipe for more pain... wheels need to be looked after more than we think they do - a pro retension by a good builder is well worth it (this from someone who owns a truing stand and spoke tension guage and builds his own wheels on occasion - but still uses a pro from time to time to check and fine tune.)

[Jewbacca]

I like Lance's opening line.. 'As a master wheelbuilder..'

 

Now I know he CAN build awesome wheels, but is there a qualification status where you go from say, 'rubbish' to 'Decent' to 'Above Average' to 'Good' etc all the way to 'Master' by way of testing or is that just a self made claim?

 

*asking for a friend.... 

[Long Wheel Base]

Where do we find the correct spoke tension for a specific wheel? Does each builder/manufacturer have their own parameter?

I was having problems with two of my rolf tandem wheels(have 2 sets) and emailed rolf in the states, They sent me a chart for their wheels. I bought a parktool spoke tensiometer and it came with a chart with so many options on it. I can't remember if the rolf and parktool charts matched up. Bought new spokes and nipples from rolf and re tensioned according to their chart and so far so good.

So for all my other wheels, would the parktool chart be sufficient?

[nick_the_wheelbuilder]

What a can of worms!

 

Here' my 2c worth:

• Break more than 2 spokes on a single wheel within a year, get it rebuilt with all new double butted spokes and brass nipples (by someone competent and experienced)
• Wider rims are generally stronger, so consider a rim with at least 25mm inner width. There are other benefits to this as well, like grip and comfort.
• Don't go for a wheel with less than 32 spokes
• Most wheels that cmoe as stock on bikes costing less than R50k are not great - machine built with narrow rims, plain gauge spokes and often alloy nipples. A hand-built, custom wheelset is one of the best upgrades you can give your bike.

 

If you want to chat about it, give me a ring. My number is here: www.wheelbuilder.co.za - I'm in northern JHB.

[Jewbacca]

Where do we find the correct spoke tension for a specific wheel? Does each builder/manufacturer have their own parameter?

I was having problems with two of my rolf tandem wheels(have 2 sets) and emailed rolf in the states, They sent me a chart for their wheels. I bought a parktool spoke tensiometer and it came with a chart with so many options on it. I can't remember if the rolf and parktool charts matched up. Bought new spokes and nipples from rolf and re tensioned according to their chart and so far so good.

So for all my other wheels, would the parktool chart be sufficient?

My spoke tension meter chart has weight/tension to spoke readings. (So a different reading = the same kgf on say a 2mm straight gauge vs a bladed spoke).

 

So the builder takes into account what the wheel is for and who will be riding it, decides on a relevant tension and then builds that.

 

The parts 'should' have a minimum/maximum limit. 100kgf is not "right" but is tight enough. If you go tighter know why and how much as it could land up being too tight causing the wheel to be more prone to 'taco tuesday'. Going half that tight is rarely disastrous.

 

Too tight is worse than too loose.. I also use a mixture of Synthetic oil lubricant and linseed oil on the threads... far too many gorilla hands cranking nipples willy nilly these days

[Weimaraner1]

Where do we find the correct spoke tension for a specific wheel? Does each builder/manufacturer have their own parameter?

I was having problems with two of my rolf tandem wheels(have 2 sets) and emailed rolf in the states, They sent me a chart for their wheels. I bought a parktool spoke tensiometer and it came with a chart with so many options on it. I can't remember if the rolf and parktool charts matched up. Bought new spokes and nipples from rolf and re tensioned according to their chart and so far so good.

So for all my other wheels, would the parktool chart be sufficient?

I always check first on the manufacturer site and follow their tension.

If I remember correctly the Park Tool TM does not give the tension reading but rather a factor which you then have to reference to the chart to get the tension. The DT Swiss TM are the best but very $$$$. Many experienced wheel builders will not need a tension meter. It is all about the feel and the sound of the spoke after it has been de-stressed. 

[CdT85]

Just something else to think off as well. Maybe have your wheels re laced with the 4 cross in stead of the 3 cross pattern if you want to stick to 32H rather than 36H rims.

 

Just get someone that know what they do, because most bicycle shops leave half your spokes "pap" when truing your wheels. I always have the habit of checking my spoke tension post ride every time due to my luck this far with destroying rims

[OldBull]

Hi all.

 

Went for a longish ride, 66km, on some real crappy gravel roads. Even had a very hard bump when my back wheel dropped into a open slot on a bridge with my full weignt on it.

 

All my spokes are still in one piece and they all feel tight. I will report back here if it breaks again.

[shaper]

My spoke tension meter chart has weight/tension to spoke readings. (So a different reading = the same kgf on say a 2mm straight gauge vs a bladed spoke).

 

So the builder takes into account what the wheel is for and who will be riding it, decides on a relevant tension and then builds that.

 

The parts 'should' have a minimum/maximum limit. 100kgf is not "right" but is tight enough. If you go tighter know why and how much as it could land up being too tight causing the wheel to be more prone to 'taco tuesday'. Going half that tight is rarely disastrous.

 

Too tight is worse than too loose.. I also use a mixture of Synthetic oil lubricant and linseed oil on the threads... far too many gorilla hands cranking nipples willy nilly these days

You can also use the Park Tool Wheel Tension App http://www.parktool.com/blog/repair-help/wheel-tension-balance-app-instructions

 

http://www.parktool.com/wta

[rudi-h]

i read a lot of stuff about building a durable bike before i set off on a long bike tour a few years back.

 

high spoke tension makes for a stiff and responsive wheel.  this is ideal for technical racing etc, but the consensus seems to be that if you drop the spoke tension, the spokes last way longer.  if i recall it was Marc Beaumont that wrote a long section of his book about his wheel build and issues experienced when he did his "cycle around the world" record.

[Nuffy]

Any thoughts on using a thread lock on the nipple threads?

 

A mechanic who built a wheel for me years ago said he always does this, so they don’t rattle loose. But I’d think it would only complicate things further down the line when the spokes need to be retensioned or adjusted. Or do you use one that’s not so strong that you can’t move the threads later?

 

I see Jewbacca says he uses “…a mixture of Synthetic oil lubricant and linseed oil on the threads,” which seems like the opposite advice, though I can understand not wanting the threads to seize…

[David Marshall]

i read a lot of stuff about building a durable bike before i set off on a long bike tour a few years back.

 

high spoke tension makes for a stiff and responsive wheel.  this is ideal for technical racing etc, but the consensus seems to be that if you drop the spoke tension, the spokes last way longer.  if i recall it was Marc Beaumont that wrote a long section of his book about his wheel build and issues experienced when he did his "cycle around the world" record.

Now you have ruined my day!  Spokes break from fatigue.  Movement causes fatigue therefore the more tension that you have and the more spokes and the more crosses in the lace and the stiffer the rim the longer the spokes will last because spokes and rim will move less!  Scientifically and empirically proven.