# Spoke length and nipple size variance



## Rock Rider (Sep 30, 2014)

I recently purchased a set of Mavic Open Pro rims (32H), and Shimano Tiagra (FH-4400 & HB-4400) hubs, and had the LBS built them up for me, lacing them using a 3 cross pattern.

I also purchase some spare spokes and an all-purpose spoke wrench, so I can learn to true my own wheels later on.

The LBS used 294mm spokes for the front, 291mm for the rear drive side, and 293mm rear non-drive side. 

Based on my own individual research, (reading the various cycling forum posts and trying to use the on-line spoke calculators ie: DT Spoke & Damon Rinard, and a few more others), I came up with an average spoke length number: Front: 295/296mm, Rear Non-Drive: 296/295mm, and Rear Drive: 294/293mm.

Question #1: I don’t know if my numbers are correct, (but assuming that they are), does a 2mm difference between the LBS number and my number make a difference? I’ve read somewhere that spokes stretch over time, and a 1mm difference is really insignificant, but where do you draw the line? 2mm? 3mm? 4mm?

Second issue. After tinkering with my new spoke wrench, I noticed that the front rim had different size nipples. Even some of the spare spokes I purchased had different size nipples. Some were the shorter 12mm (3.5mm diameter) kind, and the others were the longer 14mm (3.2mm diameter).

Question #2: even though the wheels appear to spin straight (ie true), should I bring the front wheel back and complain that they used different nipples, and have them use the same size nipple on all of the 32 spokes (either 12mm or 14mm)? For some odd reason, the rear wheel are all uniform and use the “normal” 12mm nipples.

The LBS is a long way off (40 minute drive), so I will have to make a concerted effort to trek out there. Just wondering if the 2mm spoke length difference and the different nipple sizes are worth the time and effort.

Thanks in advance.


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## Mike T. (Feb 3, 2004)

Rock Rider said:


> The LBS used 294mm spokes for the front, 291mm for the rear drive side, and 293mm rear non-drive side.
> Based on my own individual research, (reading the various cycling forum posts and trying to use the on-line spoke calculators ie: DT Spoke & Damon Rinard, and a few more others), I came up with an average spoke length number: Front: 295/296mm, Rear Non-Drive: 296/295mm, and Rear Drive: 294/293mm.
> 
> Question #1: I don’t know if my numbers are correct, (but assuming that they are), does a 2mm difference between the LBS number and my number make a difference? I’ve read somewhere that spokes stretch over time, and a 1mm difference is really insignificant, but where do you draw the line? 2mm? 3mm? 4mm?


It's recommended that online data for hub and rim dimensions not be relied on as it's been known to be incorrect. It's recommended that you measure rim (ERD) and hub dimensions yourself but this is not possible, now that the wheels are already built. No matter, as the acid test as to whether the correct spokes were used is to look where the ends of the spokes are, relative to the ends of the nipples.

The ideal place for the spoke ends to be is as the bottom of the screwdriver slot in the nipple head. There is an allowable variance of +/-1mm from this before problems start to happen - threads bottoming out when spokes are too long (spokes sticking out of the nipple top by 1mm are probably bottoming out on their threads) or not enough spoke up into the nipple head (leaving the nipple neck vulnerable to snapping off).

Look at this fine piece of information -

Freespoke



> Second issue. After tinkering with my new spoke wrench, I noticed that the front rim had different size nipples. Even some of the spare spokes I purchased had different size nipples. Some were the shorter 12mm (3.5mm diameter) kind, and the others were the longer 14mm (3.2mm diameter).


It seems like you have a fuster-cluck going on here. This says to me (without the luxury of seeing the parts) that longer nipples were used (12mm is the norm) to compensate for some spokes being too short. I don't know whether the two diameters (3.5mm & 3.2mm) means that you have two different gauge spokes in that wheel (14g & 15g.) Can you measure the spoke thicknesses with a vernier caliper? Measure within a 1/4" of the nipples.



> Question #2: even though the wheels appear to spin straight (ie true), should I bring the front wheel back and complain that they used different nipples, and have them use the same size nipple on all of the 32 spokes (either 12mm or 14mm)? For some odd reason, the rear wheel are all uniform and use the “normal” 12mm nipples.


Yup. I'd be having them explain themselves. But be armed with the info about proper spoke length when you go (info above). If they made these mistakes it would make me wonder what else they didn't do right. Read my site for much info on what makes for good wheels. The ability to own and hold a spoke wrench doesn't make someone an expert wheelbuilder.


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## BelgianHammer (Apr 10, 2012)

"...*.a fuster-cluck going on here*."

Lol, and now my Sunday is complete 

RockRider, Mike T is our resident guru here (well deserved too). Listen to him, and also peruse his site, it is awesome. Echoing Mike in saying it is hard to 100% know what is going on, but, still, reading your post, it is stuff like this that makes one get angry at bike shops and their owners (_know, though, that there are many excellent bike shops out there, you just have to make sure you ask around first, and ask many riders_). The one area any bike shop should never cut corners on for a customers are the wheels, above all else, imho. 'Cause if the wheel build should possibly fail due (stealing Mike's words) a "fuster cluck" spoke length difference build, it can obviously have serious repercussions for you and your health/well-being. 

So, not trying to be elitest and say that different spoke lengths & nipples can never, EVER be used (usually only in a pinch), but if you paid good money, you and your wheels deserve better than what you received. Good luck and, yes, go back to that bike shop, be firm, and ask the owner to make it right.


Not I must now return to my Sunday Psalms to cleanse thy burning eyes after reading Mike's words...


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## dcgriz (Feb 13, 2011)

You have not indicated whether you have ridden these wheels, for how long and whether they have remained true.

Your description indicates a rather sloppy approach from your builder, if this is truly the case then you may have another surprise coming down the road.

Flip your bike over and pluck the spokes one by one. Hold the wheel from the tire and pluck at the mid point between the nipple and the first cross. The sound between spokes from the same side (rear wheel) and between all spokes of the front wheel should sound the same if the spoke tensions have been equalized. If they have not the wheel will not stay true after repeated use, spokes will break at the elbows, etc. Check a YouTube vide to see how spoke plucking is done and what kind of sound to expect.

If you do the plucking test and you find things are not the way they are supposed to be then this will be another subject to discuss with your builder.

Regarding your statement about spoke stretching 2mm and the like. Spokes do not stretch to the degree you could measure with your ruler. They need to operate within their elastic region and remain tight but this elongation can not be measured without special instruments. So for our purposes it is safe to generalize and say they don't stretch to any level that would affect their length selection. The +/- 1mm rule is simply an indication of the acceptable tolerance in spoke length after considering the spoke-nipple interphase. Nothing more than that.


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## Rock Rider (Sep 30, 2014)

Mike T, thanks for the link. Seeing an actual picture of the spoke and the nipple really helps me understand where the ideal spoke should end up, which is “State 3: spoke end flush with bottom of screwdriver slot.” Now that I know what to look for, so I can double check their work. 

I am very tempted to take off the tire and see where the end of the spokes end up, but the only reason I am hesitating is when I bring it back to the LBS, I want to bring both wheels back intact with titres, so they can’t say I messed around with their work, thus voiding whatever warranty they have.

Sorry, I don’t have a Vernier caliper, so I can’t say for certain what gauge the spokes are, but I’m assuming that they are 14g. Looking at the spare spokes that I got, they seem to be the same length and diameter, 294mm. I unscrewed a few spokes, and using the same spoke, I can screw the spoke into both the 12mm and 14mm nipples. Does this mean that 14g spokes can use both 12mm and 14mm nipples? 

Reading your reply, Mike T, I get the sense that you are implying that only 14g spokes uses the “normal” 12mm nipples, while only the 15g spokes uses the longer 14mm nipples. Am I reading your reply right?

The 3.2mm and 3.5mm diameters are the indicators from my multi-spoke wrench. It’s one of those wrenches with multiple holes, 3.2, 3.3, 3.5, and 4.0. the shorter 12mm nipple fits the 3.5 hole in my spoke wrench, and the longer nipper (14mm) fits the 3.2 hole.

Belgian Hammer, while I can pretty much replace most parts on my bike, wheel building is the one thing I have not tackled yet. Some of the tools seems pretty expensive, ie truing stand, Vernier caliper, tension meter, Dishing tool? My wife would have a cow if I plowed in more cash into this already expensive hobby. So, I figured, going the LBS route for my wheel builds would the cheaper route.

DC Gritz. I have not ridden the new OPs yet. It’s still raining, so I wanted to wait until dryer weather being trying them out. When I say they are true, I meant that I pulled out my regular wheels, and popped the OPs onto my bike, and see if they are centered. After spinning the OPs, they seem to spin straight, with no discernible wobbles, so, I concluded that the LBS did a good job and the OP wheels are true. Like I said, I don’t have a truing stand, so this is the only way I can tell whether they are true or not, not that scientific, I know.

Doing the plucking test at the midpoint of the spokes, they seem to sound the same. Also, I squeezed the spokes, and they seem to be equally tensioned. Of course, absent a tension meter, i can't be 100% sure. But, nothing besides the use of different size nipples seems to indicate a potential problem.

But, I think I will make time and go back to the LBS, and ask why they used different size nipples. Now that Mike T told about the “Freespoke pictures”, I can ask them to take off the tires, so we can see whether the end of the spokes are flush with the bottom of the screwdriver slot.

If I don’t get a satisfactory answer, then I may have to bite the bullet and learn about wheel-building on my own. I will check out your wheel building site, Mike T.

Thanks, guys.


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## Mike T. (Feb 3, 2004)

Rock Rider said:


> Sorry, I don’t have a Vernier caliper, so I can’t say for certain what gauge the spokes are, but I’m assuming that they are 14g. Looking at the spare spokes that I got, they seem to be the same length and diameter, 294mm. I unscrewed a few spokes, and using the same spoke, I can screw the spoke into both the 12mm and 14mm nipples. Does this mean that 14g spokes can use both 12mm and 14mm nipples?
> 
> Reading your reply, Mike T, I get the sense that you are implying that only 14g spokes uses the “normal” 12mm nipples, while only the 15g spokes uses the longer 14mm nipples. Am I reading your reply right?


Spoke gauge has nothing to do with nipple length. There are (AFAIK) 12/14/16mm nipple lengths in both 14 & 15 gauge. And 15g spokes will screw into 14g nipples but I'll bet they would easily strip the threads if tension was applied.



> Belgian Hammer, while I can pretty much replace most parts on my bike, wheel building is the one thing I have not tackled yet. Some of the tools seems pretty expensive, ie truing stand, Vernier caliper, tension meter, Dishing tool? My wife would have a cow if I plowed in more cash into this already expensive hobby. So, I figured, going the LBS route for my wheel builds would the cheaper route.


If you read my site you would know that wheels can be built with hardly any more than a spoke wrench and the bike frame & fork. I did it that way for a few decades.



> they seem to spin straight, with no discernible wobbles, so, I concluded that the LBS did a good job and the OP wheels are true. Like I said, I don’t have a truing stand, so this is the only way I can tell whether they are true or not, not that scientific, I know.


Your wheel in the frame and your thumb as a gauge is a fine way of checking the trueness of a wheel. See my photo.



> If I don’t get a satisfactory answer, then I may have to bite the bullet and learn about wheel-building on my own. I will check out your wheel building site, Mike T.


That's a good reason to get into the sport of wheelbuilding.


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## dcgriz (Feb 13, 2011)

Rock Rider said:


> DC Gritz. I have not ridden the new OPs yet. It’s still raining, so I wanted to wait until dryer weather being trying them out. When I say they are true, I meant that I pulled out my regular wheels, and popped the OPs onto my bike, and see if they are centered. After spinning the OPs, they seem to spin straight, with no discernible wobbles, so, I concluded that the LBS did a good job and the OP wheels are true. Like I said, I don’t have a truing stand, so this is the only way I can tell whether they are true or not, not that scientific, I know.
> 
> Doing the plucking test at the midpoint of the spokes, they seem to sound the same. Also, I squeezed the spokes, and they seem to be equally tensioned. Of course, absent a tension meter, i can't be 100% sure. But, nothing besides the use of different size nipples seems to indicate a potential problem.
> 
> But, I think I will make time and go back to the LBS, and ask why they used different size nipples. Now that Mike T told about the “Freespoke pictures”, I can ask them to take off the tires, so we can see whether the end of the spokes are flush with the bottom of the screwdriver slot.


That's good news. The plucking test IS the test to use to determine whether the spoke tensions are equal or close to being equal to each other. The pitch changes depending on how tight the spoke is. Same pitch means same tension.

An indication on whether the applied tension is at its maximum for the specific wheel, absent of a tensionmeter, could be obtained by squeezing the most parallel spoke pairs all around the wheel and then see how true the wheel remains (two parallel spokes of the same wheel side at one hand, the opposite wheel side two parallel spokes on the other hand, squeeze hard, grab next 2 pair and repeat until all spokes are squeezed in pairs of 2 and 4 at a time). If the wheel remains true or close to true tension is about right, if it wobbles excessively it's not enough. This procedure really needs to be done by the builder when the wheel is being build. If it's not done repeatedly/adequately throughout the course of the build it usually becomes one of the primary causes of premature spoke failure when the wheel is put to use.

The very first time you ride these wheels be on the lookout for any pinging noises. If you hear any it is an indication that there was still spoke windup left in the wheel and now is relieved as the spoke goes through its load-unload cycle with each wheel rotation under load. Some builders argue that noises like these and the re-truing that follows are normal and to be expected as the wheel "settles down". I don't agree with this. IMO, wheels that DO NOT ping and/or need re-truing after the first 50 miles are examples of a high quality build where all the "settling down" took place at the builder's table and not under the rider's butt.

BTW, why are you so concerned about taking the tire off the wheel? What would you do if you have a flat? Take the tire off, remove the strip around the rim and look at nipple shoulders to see where the spokes end. You are not voiding any warranty unless you change the spoke tension on your own which you should not do prior to understanding the wheel building process.


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## BikeLayne (Apr 4, 2014)

I built this exact same wheel for my son-in-law a couple years ago. I used DT competition spokes with 297mm spokes on the front and 293/291 spokes on the rear. I remember being pleased with the fit of the spokes but it's been a long time since the build. He is still riding on the wheels and they have proven to be durable enough. Probably 8k on the wheels at this time. I keep a folder on the computer and record spoke length and other measurements is why I know what I used. I used DT 12mm nipples.

I like to see the spokes fully engage the nipple threads which occurs just slightly below the surface of the nipple (distal side). I also am satisfied it the spokes protrude 1mm past the nipple. On length it is imperative that the spoke threads do not bottom out when tensioned. Extra room is required also. 

I cannot answer to the bike shop using various nipples or spokes but it sounds like they substituted less then desireable parts due to lack of inventory. I would go back and deal with the bike shop. Afterwards I would not return to the store. 

If you look under the rim tape you can see where the ends are located in relationship to the nipples. 

I am not an expert on wheel building but I have built my own wheels and for some friends for 40 years now. Maybe 20 sets of wheels. At first I just used my bike as a truing stand and just centered the wheel in the bike for dishing. A Pencil over the brake pads to get the wheel round and the pads themselves to get the wheel flat. It worked fine for a long time. Over time I acquired some tools and bought a cheap stand and dishing tool mail order back in the day when you filled out a form and included a check. I still use the same tools. I bought a Park tension tool a couple years ago and enjoy using it. 

I just built a new set of wheels using the H+ Archtype/105 hubs 32 holes and DT competition spokes 3x in the rear and DT Revo's 3x in the front. I have about 500 miles on the wheels and they seem to be real nice. I hope to enjoy the wheels for a long time. 

I hope I said something of help. Good luck.


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## robt57 (Jul 23, 2011)

One possible explanation could be he had to use different nips where he may have used washers if the washer hole was too tight on the first ones or something. Once the builder started bottoming spokes while tensioning possibly back tracking and using washers an the different nips.. 

My last build I intentionally used brass for some spokes, AL for the rest. It is also possible he used a combo of brass and Al nips for a purpose, and unlike me did not have the exact length nips in both on hand.


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## Drew Eckhardt (Nov 11, 2009)

Rock Rider said:


> I recently purchased a set of Mavic Open Pro rims (32H), and Shimano Tiagra (FH-4400 & HB-4400) hubs, and had the LBS built them up for me, lacing them using a 3 cross pattern.
> 
> I also purchase some spare spokes and an all-purpose spoke wrench, so I can learn to true my own wheels later on.
> 
> ...


Yes.

Aiming for the nipple end, with some combinations (DT spokes and DT 12mm nipples) 2mm too long will cause the spokes to bottom before you get to full tension.

Aiming for the slot, 2mm too short will load the nipples in tension not compression and perhaps break nipples (especially aluminum ones).

You always need to measure the rims you're using.

Look at where the nipples end. Any where from 1mm below the slot to 1mm beyond the top is fine, although departing too much from perfect may mean you don't have enough tolerance to safely re-use the spokes with an "identical" replacement rim that ends up a bit smaller or larger due to things like extruder die wear.



> I’ve read somewhere that spokes stretch over time


No. You get about 1mm at full tension from 1.5mm spokes front and rear drive-side but they spring back when you release tension.



> Second issue. After tinkering with my new spoke wrench, I noticed that the front rim had different size nipples. Even some of the spare spokes I purchased had different size nipples. Some were the shorter 12mm (3.5mm diameter) kind, and the others were the longer 14mm (3.2mm diameter).


That can be a huge problem. DT nipples have the same length of un-threaded portion, so 2mm more nipple means the spoke bottoms 2mm sooner.

The builder could be compensating for some spokes being too short although that invites nipple breakage especially using aluminum nipples.

They could have also laced the wheel wrong.

With the low end of the market buying $25 QBP wheels and high end mostly boutique LBSes don't build a lot of wheels these days so their mechanics aren't experienced enough to do a good job sufficiently fast to turn a profit.

Most compromise by doing a fast bad job so they can get back to more profitable endeavors like $20 cable replacements (x 4 = $80).



> Question #2: even though the wheels appear to spin straight (ie true), should I bring the front wheel back and complain that they used different nipples, and have them use the same size nipple on all of the 32 spokes (either 12mm or 14mm)?


Yes.


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