# Spoke Tension



## daniell (Apr 12, 2002)

I am thinking of buying the Park tensionometer.
For a given rim, how would I know the correct tension?

Thanks


----------



## danl1 (Jul 23, 2005)

daniell said:


> I am thinking of buying the Park tensionometer.
> For a given rim, how would I know the correct tension?
> 
> Thanks


There's not a general answer; though individuals do have rules of thumb that they follow, there don't seem to be many that are widely accepted. 

Which leaves 'ask the rim manufacturer,' or 'ask experienced others about what has worked.' I don't have a broad set of experience, but I've always been able to search and find the manufacturer's recommendations, either directly, or through the research of others. 

Jobst Brandt has a technique that is essentially 'you'll know when you've found it when you go too far.' For those familiar, yes, I'm oversimplifying. I personally don't like that technique, in part because he tends to pre-assume socketed, standard-depth aluminum rims, and the broader experience (carbon rims, eyeletless rims, etc) mean that has arguably less merit than the base case. But, it's an opinion, and I could be all wet.


----------



## cxwrench (Nov 9, 2004)

you'll get a chart w/ the park tool that has just about every possible spoke size/material cross referenced w/ the numbers on the tool. generally, 100kg is considered adequate, but some rims will take more. check w/ your rim manufacturer and then find the type of spoke you are using on the chart and you'll find a number that will equate to the proper tension reading on the tool. it varies w/ the spoke diameter/materia and whether the spoke is bladed or not. 
for example, 100kg would be a reading of 15 or so for a DT Aerolite, but it would be over 20 for a DT Comp. you'll understand when you get the tool.


----------



## ergott (Feb 26, 2006)

Zen Cyclery said:


> Your spoke tension is also highly dependent on spoke choice.


Could you please explain this?

-Eric


----------



## Zen Cyclery (Mar 10, 2009)

Well, the rim manufacturer will usually specify what the suggested tension is for their hoops. Your spoke tension is also highly dependent on spoke choice. Do you know what parts you will be using?


----------



## looigi (Nov 24, 2010)

Big diff between drive and non-drive side on the rear, of course. I talked to HED on the phone and the gave recommended tensions.


----------



## Zen Cyclery (Mar 10, 2009)

ergott said:


> Could you please explain this?
> 
> -Eric


Well, different spokes (ie bladed vs round) are going to correlate to different areas on the tensiometer. Additionally, I wouldn't tension a Wally World wheel to the range as a high end carbon one.


----------



## ergott (Feb 26, 2006)

Zen Cyclery said:


> Well, different spokes (ie bladed vs round) are going to correlate to different areas on the tensiometer. Additionally, I wouldn't tension a Wally World wheel to the range as a high end carbon one.


The recommended tension of the spoke would be the same regardless of the spoke used. It's the conversion on the gauge that differs. Spoke type doesn't effect recommended tension, the rims (and sometimes the hubs) do. That's what the OP was asking.

-Eric


----------



## Zen Cyclery (Mar 10, 2009)

ergott said:


> The recommended tension of the spoke would be the same regardless of the spoke used. It's the conversion on the gauge that differs. Spoke type doesn't effect recommended tension, the rims (and sometimes the hubs) do. That's what the OP was asking.
> 
> -Eric


So your saying all spokes have the same max tension limit?


----------



## ergott (Feb 26, 2006)

Zen Cyclery said:


> So your saying all spokes have the same max tension limit?


Please reread my post. That's not what I said at all.

-Eric


----------



## Zen Cyclery (Mar 10, 2009)

ergott said:


> Please reread my post. That's not what I said at all.
> 
> -Eric


 Many spokes have many different tension capability ranges, and saying that spoke type has nothing to do with spoke tension is quite untrue. :idea:


----------



## sp3000 (Jul 10, 2007)

ergott said:


> Please reread my post. That's not what I said at all.
> 
> -Eric


To clarify:

The park tool tension meter reads the deflection of the spoke, every different spoke will deflect differently given they are under the same tension. For example a thick aluminium spoke will deflect less than a thin steel spoke, that gives the tension meter different readings. This is why you have a comparison chart that comes with the tool, so you can line up the tool reading to the correct spoke type to get the actual tension of the spoke.


----------



## ergott (Feb 26, 2006)

Zen Cyclery said:


> Many spokes have many different tension capability ranges, and saying that spoke type has nothing to do with spoke tension is quite untrue. :idea:


The maximum recommended tension of any spoke I work with (Sapim, DT, Wheelsmith) far exceeds the recommended tension of any bicycle wheel.

Please give me an example of a wheel build you have done where the spokes maximum tension was lower then the rest of the components.

Where are you getting your information?

-Eric


----------



## ergott (Feb 26, 2006)

sp3000 said:


> To clarify:
> 
> The park tool tension meter reads the deflection of the spoke, every different spoke will deflect differently given they are under the same tension. For example a thick aluminium spoke will deflect less than a thin steel spoke, that gives the tension meter different readings. This is why you have a comparison chart that comes with the tool, so you can line up the tool reading to the correct spoke type to get the actual tension of the spoke.


I'm well aware. I have one. The goal is to have accurate tension for a variety of spokes. You still don't adjust your recommended maximum tension based on spoke choice.

-Eric


----------



## sp3000 (Jul 10, 2007)

ergott said:


> I'm well aware. I have one. The goal is to have accurate tension for a variety of spokes. You still don't adjust your recommended maximum tension based on spoke choice.
> 
> -Eric


Thanks, this was to help the OP understand about the tool.


----------



## ergott (Feb 26, 2006)

sp3000 said:


> Thanks, this was to help the OP understand about the tool.


No problem. I wasn't sure why you used that quote for your response.

-Eric


----------



## cxwrench (Nov 9, 2004)

Zen Cyclery said:


> Many spokes have many different tension capability ranges, and saying that spoke type has nothing to do with spoke tension is quite untrue. :idea:


 :nono:



ergott said:


> The maximum recommended tension of any spoke I work with (Sapim, DT, Wheelsmith) far exceeds the recommended tension of any bicycle wheel.
> 
> Please give me an example of a wheel build you have done where the spokes maximum tension was lower then the rest of the components.
> 
> ...


:yesnod:


----------



## mhudgens (Jan 21, 2011)

ya'll still jumbled confusion. Bottom line is what is the spoke...what is the rim... What does the rim and spoke manufacture recommend...usually around 90-110 kg .....the rest is racer feel! Paris Roubaix is like 85KG and then up from there.


----------



## cxwrench (Nov 9, 2004)

mhudgens said:


> ya'll still jumbled confusion. Bottom line is what is the spoke...what is the rim... What does the rim and spoke manufacture recommend...usually around 90-110 kg .....the rest is racer feel! Paris Roubaix is like 85KG and then up from there.


not really...like eric posted, it doesn't really matter what the spoke is. the limitations are the rim and the hub. every spoke i've ever used is more than strong enough for every rim i've ever seen.


----------



## mhudgens (Jan 21, 2011)

OK so let's pretend that is true....and lets QUOTE.... the limitations are the rim and the hub. every spoke i've ever used is more than strong enough for every rim i've ever seen. 

Why do spokes break at the elbow or the nipple?

Over or under tension. 

Usually OVER tension an pop...that's why larger diameter elbows came into play because as spoke numbers decreased, spoke tension increased. Less spokes and higher tension equaled higher spoke failure. Shorter spokes, longer nipples and balanced tension of spokes make strong wheels when you look at todays wheels. 
Most wheels from China come in severely undertension. with a 20/24 figuration. Then most take to shop who jump the tension up because they are not true or???

My take is...look at total wheel tension and balance all spokes and nipples. 100 hg is a good starting point for most. That is the quoted tension for most China wheels. If it is soft or hard then a turn or so should correct the problem..and that is all we are talking about...


----------



## rruff (Feb 28, 2006)

mhudgens said:


> Why do spokes break at the elbow or the nipple?Over or under tension.


Stress concentrations and lack of stress relieving, usually... not tension. There are very few (if any) rims that will tolerate the tension that the spoke is capable of.


----------



## BluesDawg (Mar 1, 2005)

I am curious about this question, too. I am about to build a set of A23 rims on Shimano Tiagra hubs, 32/32 and 3X with Sapim Race spokes. My LBS will loan me their Park tensionometer and I was wondering what tension to shoot for. Sounds like 100 kg would be a good target?


----------



## ergott (Feb 26, 2006)

BluesDawg said:


> I am curious about this question, too. I am about to build a set of A23 rims on Shimano Tiagra hubs, 32/32 and 3X with Sapim Race spokes. My LBS will loan me their Park tensionometer and I was wondering what tension to shoot for. Sounds like 100 kg would be a good target?


Go for 120kgf for the rear, drive side and 110kgf for the front. The non drive side of the rear wheel is what it is. It's very important to get even tension around the wheel.

-Eric


----------



## BluesDawg (Mar 1, 2005)

Eric - thanks


----------



## Zen Cyclery (Mar 10, 2009)

cxwrench said:


> every spoke i've ever used is more than strong enough for every rim i've ever seen.


Yes, very true. 

However just because any spoke can handle any rim specifications doesn't mean any spoke will be ideal. 
Here is an example.
Say you are building on a Stans 340 rim (which most builders on here know is the definitely weak link as far as tension is concerned). Now, for this build I would never pick a spoke like a Pillar XTRA. Not because the spoke can't handle the tension, but because if you were to run these at the tension Stans recommends, they would be horribly soft. 

So yes, this does prove the point that rims are usually the limiter, however it also shows that spoke choice can have a huge effect on overall build quality.


----------



## ergott (Feb 26, 2006)

Zen Cyclery said:


> Not because the spoke can't handle the tension, but because if you were to run these at the tension Stans recommends, they would be horribly soft.




Again, the tension of the spokes has nothing to do with what you are talking about. You wouldn't choose those spokes because the wheel wouldn't be stiff enough for most riders. Actually, for that rim, 32 Pillar ti spokes would be a better choice than 24 CX-Rays because they would support the rim in more places and the resultant wheel stiffness would be similar. The Pillar spokes are about 25% less stiff so increasing the spoke count would be a perfectly normal solution.

Those titanium spokes are no "softer" at 100kgf than they are at 130kgf. You really don't understand what you are talking about.

-Eric


----------



## Zen Cyclery (Mar 10, 2009)

ergott said:


> Those titanium spokes are no "softer" at 100kgf than they are at 130kgf. You really don't understand what you are talking about.
> 
> -Eric


Wow, Eric. No need to start ridiculing. 

I would like to see some data of what you are talking about. If you have some, I will eat my shoe. But I absolutely believe that ti spokes would be much softer with 30kg less tension, all though I will admit I have no studies to back that.


----------



## ergott (Feb 26, 2006)

Zen Cyclery said:


> Wow, Eric. No need to start ridiculing.
> 
> I would like to see some data of what you are talking about. If you have some, I will eat my shoe. But I absolutely believe that ti spokes would be much softer with 30kg less tension, all though I will admit I have no studies to back that.


Wheel Stiffness Test

Titanium will behave like steel. It's basic science.

[edit]

-Eric


----------



## Zen Cyclery (Mar 10, 2009)

ergott said:


> Wheel Stiffness Test
> 
> 
> -Eric



Foot is officially in mouth. Definitely learned something new with this link.


----------



## rruff (Feb 28, 2006)

Zen Cyclery said:


> But I absolutely believe that ti spokes would be much softer with 30kg less tension, all though I will admit I have no studies to back that.


If a wheel gets "soft" with low tension, it means that the spokes are going slack. The rim gets relatively very flexible when that happens.


----------



## daniell (Apr 12, 2002)

ergott said:


> Go for 120kgf for the rear, drive side and 110kgf for the front. The non drive side of the rear wheel is what it is. It's very important to get even tension around the wheel.
> 
> -Eric


One thing that I could never understand. If the wheel is true both vertically and laterally, wouldn't the spoke tension be at least close to even? If the spoke tension was not equal, the wheel would not be true.


----------



## valleycyclist (Nov 1, 2009)

daniell said:


> One thing that I could never understand. If the wheel is true both vertically and laterally, wouldn't the spoke tension be at least close to even? If the spoke tension was not equal, the wheel would not be true.


On the rear wheel the flanges are not equidistant from the center of the hub due to the cassette. The drive side flange is much closer to the center of the hub than the non-drive side flange which gives you a spoke tension difference when the wheel is properly dished.

You want the spokes on each side of the wheel to be at about the same tension as the other spokes on the same side which will give you a true wheel.


----------



## ergott (Feb 26, 2006)

daniell said:


> One thing that I could never understand. If the wheel is true both vertically and laterally, wouldn't the spoke tension be at least close to even? If the spoke tension was not equal, the wheel would not be true.


Small differences in rim thickness from the extrusion process and rims not being perfectly round are reasons why it won't. Rims are extruded into a coil, cut into lops and joined by welding, pinning, a sleeve or sometimes a combination. The joint area is usually the biggest reason why rims are never perfectly true and with perfectly even tension.

No rim is perfect. Better rims are very true and result in very even tension. Some rims can't be made as true with even tension. The balance between the two is up to the wheelbuilder. Even tension is a bigger priority.

-Eric


----------



## Drew Eckhardt (Nov 11, 2009)

daniell said:


> One thing that I could never understand. If the wheel is true both vertically and laterally, wouldn't the spoke tension be at least close to even? If the spoke tension was not equal, the wheel would not be true.


Nope. Rim stiffness gives you some latitude in where you apply tension with spokes.

For instance a wheel with a perfect (within manufacturing tolerances) rim could be true with three adjacent spokes in one side at the same tension, loose spokes on the outside with a tight one in the middle, or tight spokes on the outside with a loose one in the middle. This results from successive small changes made without spreading the tightness around instead of larger ones where you might use half a turn at the middle and a quarter turn on the adjacent spokes.

With bent rims on (as good as you can get) true wheels you can also have very loose spokes that the rim is bent towards and nearby very tight spokes that it's bent away from.

The imbalanced situations are more likely to have problems with nipples unscrewing or stress cracks.


----------

