Jarrett2

I'm a clyde that has struggled with rear wheel issues since day one. I'm trying to learn more about wheel maintenance and hopefully building so that I can get to a point of maintaining some reliable wheels.

I just received a Park TM-1 tension meter today and checking tension on my current wheelset was confusing. The wheelset is a DT Swiss RR440/32h/Ultegra hubbed setup with some type of DT Swiss spokes. That was my first bit of confusion, when using the spoke gauge tool, the spoke seems to be 1.5 in the middle, but swells out to 2.0 as it gets to the nipple. So I'm not sure how that falls on the chart. How does that work?

I also had some confusion with the tension readings. For example, the wheel is true, but the tension numbers seem to be all over the place. On the drive side, they seem to be fairly consistent at around 15-20 on the tool between each. Meaning one of the crossed pair will be around 15 on the tool and the other spoke in the pair will be around 20.

But on the non drive side of the same wheel, it's all over the place. Some of them are a 3, some of them are 11 and anywhere in between.

The front wheel is similar. Various numbers on both sides of the wheel.

Is this what a correctly built wheel is supposed to look like? If not, how do I get started fixing it? What do my spoke tensions need to be at for a 260lb rider on rough, country roads?

Any help would be greatly appreciated. Thanks.

jyl

Measure spoke gauge at the thinnest point, in the center.

Some variation in tension between spokes on the same side is okay, but what you're describing on the non drive side is way too much variation. The variation on the drive side is a bit too much too.

Think in terms of kgf, the numbers on the meter need to be translated to kgf using the spoke gauge.

So for 1.5 mm round steel spokes, your drive side 15 on meter is 88 kgf, 20 on meter is 148 kgf. More experienced people will weigh in here, but in my limited experience I would look for around 130-140 kgf [EDIT: err, maybe not - see below] with the exact kgf less important than keeping it fairly consistent.

For your non drive side, 3 on meter is off the scale too low tension, you might want to re-check, if that is indeed the right measurement, that spoke is unacceptably loose. 11 on meter is 61 kgf, still awfully loose. Non drive side spokes are always lower tension than drive side, especially with modern hubs at 9-10 speed, but I think your non drive side is too low and too uneven, and needs to be fixed. I've broken spokes where the non drive side was that loose.

Front wheel is usually easy to get even and high enough spoke tension. I'd aim for something around 120 kgf where being even is more important than hitting a specific number. Front wheel isn't loaded as much so i consider exact spoke tension less critical, I usually try to get it very true laterally just so I can run my brake pads very close to the rim. I'm not a Clyde but not far away at 190 lb in the winter . . . and I was a bona fide Clyde not all that long ago. Ride "light" which means getting off the saddle and unweighting the bike on the rough spots, and your wheels will do better.

EBIT - I just looked up specs on your rim and max tension is 1200 Newton or 122 kgf. That seems kind of low for a 450 gram rim, maybe DT Swiss is being conservative. But anyway, that is the spec so adjust/ignore what I said above, accordingly. https://www.dtswiss.com/Components/Rims-Road/RR-440

dabac

Spokes being narrower in the middle are called butted spokes and it's a good thing that usually lead to a more long-lived wheel. To read the chart, use the measurement of the narrow section.
And no, spoke tension shouldn't vary like that on a well built wheel. On externally geared wheels there'll be a fair bit of tension difference between left and right, and similar on a disc brake front. But on the same side, spoke tension shouldn't vary with more than perhaps 10% on a wheel that hasn't been tweaked by use.
With the possible exception of the spoke(s) closest to where the rim joint is.
How to fix it? For each unevenly tensioned "pair", slacken the tight spoke 1/4-1/2 turn and tighten the loose spoke an equal amount. Repeat until tension difference is similar to measurement precision or until boredom sets in.
Ideally you tension to what the rim spec suggests. If you haven't got one, 110-120 kg DS tension and then NDS whatever correct dish allows for.

FBinNY 

Let's start with the simple.

The tool measures tension by measuring "sag" when a horizontal deflection is introduced. While the tension is uniform for the entire spoke;s length (has to be) the tool's compensation factor depends on the place where you measure. You seem to have 2.0/1.5/2.0 spokes and are measuring at the 1.5 area, so that's the conversion factor (chart) you use.

As to the evenness in tension throughout the wheel. First of all, the right side will always (almost always) have higher tension than the left because the rim isn't centered between the flanges (aka, dished). The tension difference increase with the asymmetry, so I can't tell you what to expect for your wheels without knowing the distance from flange to center on both sides.

Then each side should have even tension spoke to spoke within an acceptable tolerance, and subject to rim issues. Crapshoot guideline would be within 10% of average, though hand built wheels can be much closer.

One caveat about even tension - it applies to uniform patterns, such as radial or the classic crossed patterns. However patterns that mix cross and radial spokes will have different tensions according the the spoke's route so you can';t compare a radial spoke to a tangent one.

Now YOUR wheel seems to be beyond acceptable (if you measured accurately) and I wonder if it's new (original) or someone has worked on it. If new and true, I hesitate to advise you to "correct" it because the potential to do more harm than good is very real. OTOH- if it's already been worked on and/or needs some truing, you can try to get spokes to average and reduce the spoke to spoke variance, as you true it. Go slowly and work on the low hanging fruit (worst cases) first, and slowly bring it to harmony.

Willbird

One thing I have picked up in my google work on this subject is that many such tools (I plan to buy one myself real soon here) is that they have no compensation for variation in spoke dia.

one would hope there was no variation within an untouched wheel....but if we break spoke(s) and replace them it could crop up then. Somebody or other said they started measuring the spoke dia and recording it as a meaningful data point. Some fairly expensive dial indicator based spoke tension meters are able to zero on the spokes in question to take dia variation out of the picture.

others who have micrometers and use them might have a better idea how much dia variation lot to lot is "normal".

FBinNY 

I'm glad you said "google knowledge" vs. personal knowledge or experience. Spokes are extremely consistent within very narrow tolerances. The spoke diameter tolerance is much closer than the tools measuring accuracy, resolution or repeatability. So, not counting user errors when measuring oval profile spokes, than diameter variance is a non-issue.

No micrometer is needed, but a caliper or wire gauge is handy to confirm that you're measuring what you think your measuring, especially in a repaired wheel where a different spoke might be introduced, or one built with different gauge spokes right and left. I still use a wire gauge I was given almost 50 years ago, and at some point will pass it along to the next guy.

Only enough accuracy to identify the spoke diameter, ie. 2.0, 1.8, 1.6, etc. there's no need for precision since the conversion charts are in 0.1mm increments (at best).

IMO and IME, newbies and amateurs look for too much from these tools, whereas experienced builders use them mainly as "reality checks" or QC instruments rather than building tools.

Bill Kapaun

For a 1.5mm spoke, some of the tensions seem too high.
The smallest I use is 1.6mm.
It's my understanding that 1.5mm reach a tension around 120-130ish? where they simply just start to stretch and stretch and...

davidad

If the tensions are all over the chart I would back off all of the spokes by about 3 fulls turns and start from scratch. Bring the wheel to radial true, the lateral and add tension and true until you hit desired tension. Depending on how much clyde I wouldn't go over 130K.

bigfred 

I'm very surprised that they sold you a wheel with 1.5mm spokes for clyde use. Are the drive side rears also only 1.5 in their center/thinnest section? To the best of my knowledge, the manufacturers of 2.0/1.5 ultra butted spokes only recommend them for use by "light riders" on "racing only" wheels. Such spokes generally exhibit additional stretch at clyde tensions and are incapable of achieving higher tensions. Subsequently, even if true and evenly tensioned, this rear wheel is always going to be laterally flexible.

Additionally, 1.5mm spokes will exhibit more windup during tensioning and an increased challenge at eliminating that and it's effect during truing. Definately not something I would recommend for a first timer, that hasn't built a wheel yet. You may cause yourself more frustration than education.

I recommend you download Parks tension balancing app: Park Tool Co. » ParkTool Blog » Wheel Tension Balance App Instructions

Then follow their instructions and enter your spoke values. As you are measuring each spoke, tap on the face of the meter two or three times (until the needle no longer moves) to arrive at consistant values for each spoke.

That app will provide you with a very powerful graphic tool towards understanding which spokes are over or under tensioned and how that relates to neighbooring or opposing spokes.

If I were faced with a tension range as you're describing, I too would be backing the entire wheel off and starting over. But, given your lack of experience, I'm not recommending tha to you.

Instead, Save your Park tension balance sheets and then take that wheel to one of those two trusted wheelsmiths you mentioned in your other thread. When you've gotten the wheel back from them, repeat the measure procedure and compare the tension balance charts.

You should see a huge improvement. The industry standard is that spoke tensions should vary by no more than +/- 20% (kgf). That plan an simply is inadequate for most clydes. Instead, you would hope for at least +/-10%. And there are quite a few of us who are aiming at <+/-5%.

Even if your wheelsmith gets the wheel true, and realatively high and evenly tensioned, there are going to be limits to what you can expect from 1.5mm spokes. Plain and simply, they are an ultra-light product, while you are NOT.

FBinNY 

I use plenty of 1.5mm spokes, even on wheels I build for touring, commuting and heavy riders. Yes, they are tension limited but that's never an issue for front and left side rear spokes, where there no need (or possibility) for high tensions.

The fact that they reach their ideal tension working range at lower tensions is precisely why I use them. It allows me to use 20/1.8 spokes on the right side of highly dished wheels without resorting to excessive tension.

bigfred 

You are a seasoned veteran. With almost immeasurable experience. Jarrett is not.

Furthermore, you might have noticed my question about whether he had measure the drive side or not and if that also had 1.5mm spokes. My primary concern is exactly that drive side.

Are you suggesting that it would be reasonable and advisable for us to suggest to an individual who has never built a wheel and who had not even trued a wheel prior to a few weeks ago to start his learning curve on ultra butted spokes?

He might be able to succeed. But, jeaz, it sure would be easier to talk someone through the early stages of their wheel maintenance/building life on slightly more tolerant components.

FBinNY 

No. If you read the last paragraph of my post No.4, you'd see that I as very uncomfortable advising a newbie using a tool he doesn't understand to "improve" a new wheel. I hope I was clear that improving only made sense if there were a problem.

My concern is less related to the spokes at issue than the OP's inexperience.

BTW- I don't know the wheels, but I don't know of anyone who's using 1.5mm on the right side of highly dished production wheels.

Al1943

The wheels I've built have been mostly with DT Swiss components and I've been using the Park TM-1 since it was first offered. The best advice I can offer you at this time is to be sure to release the tool slowly and smoothly onto the spokes. A quick release will result in inconsistent and inaccurate results.
Most of my wheels have DT Revolution double butted 2.0 - 1.5 - 2.0 spokes in the front and nds rear. Revolutions stretch too much on the drive side rear. This leads to inadequate tension on the nds or an off-centered rim.
When using the Park spoke gauge tool that comes with the TM1 the center section of the Revolution spokes measures less than 1.5 mm. I normally use DT Competition double butted 2.0 - 1.8 - 2.0 spokes on the drive side rear and find that it seems nearly possible to squeeze the Park 1.5 gauge onto the center of these spokes. I'm telling you this in case you are having trouble recognizing what you have. Unfortunately I don't have a high quality caliper to check the accuracy of the Park gauge or the DT spokes.

Willbird

FB here is the article where I found that info.

Wheelbuilding spoke tension and tensiometers

In my world we mostly uses inches, and the variation he is talking of is 0.00196".

Overall it is a very interesting article :-).

jyl

1.75 vs 1.80 is less than 3%. The cross sectional area would only be 5-6% different. The error in reported tension would only be about 5-6%. That doesn't seem like a "significant" over or under tension.

Jarrett2

Thanks for all the info, please keep it coming. I'm reading and absorbing.

pdlamb

I don't think I've ever dropped below 1.8 swaged spokes, so take some of this with a grain of salt.

Spokes below 50-60 kgf usually unscrew, IME. Based on that, if you're going to work on this yourself (which is a good way to learn!), I'd start by tensioning all the loose non-drive side (NDS) spokes up to that. It's still a relatively low tension, so that shouldn't throw anything too far out of true.

I usually try to get DS spokes within 2-3 "notches" on the Park tool. I'd try to unscrew the spoke at 20 a quarter turn, and tighten the adjacent spoke a quarter turn, and see how that works (tension and true).

Ultimately, truing a wheel that's been ridden a while is more of an art than a science. You want to get everything true enough to ride comfortably, and evenly tensioned enough that spokes won't spontaneously unscrew, while keeping the tension low enough that the rim won't break.

It helps if you know a good wheel builder who can fix things if you can't, but make sure that they understand you'll need the tension 10-20 kgf higher than the featherweight who just had them true that flimsy race wheel he just worked on. I've had custom wheels built for me that I had to go around and tighten a quarter turn on all the spokes, because spokes were unscrewing and breaking.

Jarrett2

Thanks. I did go back and check the spokes. I can get the 1.5 notch around the middle of the spoke, but I slide it towards the nipple, it sort of catches along the way. The 1.6 notch slides fine. I assume that means its a 1.5 spoke. And that is on both sides of the front and rear wheel.

As the 1.5 notch gets about an inch away from the nipple it stops and it appears to become a 2.0 size there.

The rear wheel has the most variance in spoke tension. From a 3 on the gauge on the NDS side to over 20 on the gauge on the DS. But the wheel appears to be perfectly in true. Not sure what to do with it in that case.

Since its a little out of true, I went ahead and put all of the front wheel spokes to around 10 on the gauge. Which didn't seem to have any noticeable impact on the true of the wheel, meaning its still out a little.

I'm going to take the bike back to the LBS where I got the wheels tomorrow and have them go through them. I'll ask them what the various tensions mean to them as well.

Jarrett2

This is making me wonder if I might have 1.8's or 1.5's or something else.

But either way, the lowerstdeflection reading their chart for 1.5 is 8 for 54 Kgf. I have several spokes under that. The lowest setting for a 1.8 spoke is 12 @ 51 Kgf. The majority of my spokes are under that out the DS spokes.

This spoke confusion makes it all a little tougher.

FBinNY 

Please take the following in the spirit intended, which is to help, not criticize.

Any kind of mechanical work is like building a house. Long before you worry about framing windows and putting on a roof, you have to build a good foundation. Your questions about fundamentals such as spoke gauge (diameter) and implied lack of understanding about butted spokes tells me that you;re not ready to move forward.

Either stay with proven basic techniques of aligning a wheel, or have someone help you with the principles of using a tension gauge. Otherwise you'll tie yourself in knots and are as likely to make your wheel worse as you are to make it better.

BTW- if there's a bike co-op, or anyone offers repair classes nearby, that might be your best course of action. This way someone can address your questions, showing you how they apply to your wheel, and guide you through the process with a mix of hands on and applied theory.

Bill Kapaun

The "notch gauge" supplied with the TM-1 is adequate for your purposes.
IF the 1.5mm notch fits in the middle of the spoke, consider it a 1.5mm.
The thing I'd be concerned about is-
Were the DS spokes overtightened and stretched?
I would eyeball the DS nipples from the tire side and see how the spoke end is in relation to the screw driver flat of the nipple.
IF some are protruding noticeably past the flat, I'd be very concerned.

bigfred 

Jarrett,

If the 1.5mm go/no go gauge fits over the center of the spoke, consider them to have a 1.5mm center section. If the smallest notch you can fit over the nipple and/or elbow end is the 2.0mm, consider those to be exactly that. In which case what you have is considered to be an ultra butted, double butted, spoke. Probably these: DT Swiss - DT revolution if they used DT components. But, possibly these: Laser | Sapim .

I'll draw your attention to this part of the Sapim description:

" The thin middle section of 1,5mm needs special care while building up the wheel. You may have to use a pliers to hold the spoke to prevent the spokes from winding up. Only experienced wheel builders should mount up wheels with this spoke.

• Longlasting
• Highly flexible
• Better shock absorption thanks to the thin middle section"

It would be highly unussual for a wheelsmith to recommend the use of either spoke on the DS of a rear wheel for a 260lbs clydesdale.

If you're LBS claims that they had built these up "for you" prior to your purchase of the Mavic Open Sport (which has also failed to provide any sort of durability) I would really question their decission making advice. Even more so, if you're request was for a "durable" wheel to replace the OEM wheels that were giving you fits.

The only way I could justify suggesting the use of such light spokes would be if there was a serious weight concern for the build.

For a clyde to get reasonable durability from a wheel and in order to build it without the use of thread locking compounds, you need approximately 70kgf of tension on the NDS. Using Shimano hubs and their reasonably consistant flange spacing, to achieve 70kgf on the NDS you need to have approximately 130kgf on the DS. 1.5mm spokes may or may not be capable of delivering that. At the very least, once tensioned to 130kgf, they will still deliver more stretch and lateral flex than would be ideal for your use.

If you've been dealing with the same LBS on all this (the OEM wheel, the Open Sport wheel and now these) it really is time to find someone/somewhere else to take your business.

If you're going to proceed with attempting a DIY on this wheel, my advice will be somewhat contrary to some of what has already been suggested. I would not further tension spokes on the NDS. In fact, I would be inclined to actually back off any NDS spokes that are already tighter than the others, until all of them are realtively even. Then I would focus on equalizing the DS spoke tension whilst maintaining lateral and radial true. Once I have the wheel evenly tensioned and true I would begin bringing the tensions up. Focusing on getting the DS up in the region of 110-120 and then using the NDS to properly dish the wheel.

This sort of approach minimizes the amount of work you are trying to do to the highly tensioned DS spokes near the end of a build.

Since the LBS sold this wheel to you with these super light spokes, do you know if it also has aluminum alloy nipples?

If so, you'll also need to be careful about not rounding those off at high tensions. And, I will increasingly be inclined to suggest you take the wheel to a wheelsmith, rather than use it as a learning experience.

All of this in combination with the realatively light A440 rims with their 21mmX21mm box section really suggests to me that these are not the wheels for you, if what you're after is a "durable" wheel.

Edit: All of this is assuming the spokes are "round" and not a bladed model. Is that the case?

Looigi

FWIW: IMO, you should get a set of calipers which enable measuring many bike related items to .001" accuracy. Under $20 at Home Depot, Lowes, Harbor Freight, etc...

Jarrett2

BigFred, thanks for all the good info. The more I learn, the more I think you are correct on this. I don't think these wheels were built for me. Based on the light spokes and the alloy nipples. If they were built for me, then I don't think the builder knew what they were doing. Regretting buying them at this point. I called to ask them what spokes they used and they said DT Swiss. I asked which ones and they said, "I don't know. Could be anything."

I checked the spokes on my Mavic Open Sports and they are double butted, 1.8-2.0. The spokes on my OEM wheels are 2.0 all the way through. So it appears these new wheels I bought that were "built for me" have the lightest spokes of any of the wheels I have. On top of that, I checked the tension on the other wheels and the new wheels have the most inconsistent tension as well. The machine built wheels had more consistent tensions between them.

FBinNY 

Not saying that a nice pair of Vernier or dial calipers isn't useful. But how would 0.02mm resolution help the OP since the tension meter conversion is in 0.1mm increments?