[antonio]

I'm trying to build a front wheel using the XTR 20mm m976 hub and DTSwiss 4.2d rims.

Based on info from the DTSwiss spoke calculator AND the Spocalc spreadsheet, I went ahead and bought 263mm spokes for 3x, but they are too long and the nipples bottom out way too early.

So, either I entered the numbers incorrectly, Cambria sent me the wrong length spokes (I am not sure on how to measure them), or the hub info I pulled from pricepoint.com is wrong.

Any help would be greatly appreciated.

Info from pricepoint:
Axle Length 108mm
Spoke Hole Circle 52mm
Center to Flange (Right) 36.4mm
Center to Flange (Left) 25.2mm

Antonio

 

[CupOfJava]

Based on my numbers the spoke length should be: 263.7mm

ERD: 544
Flange Diameter: 52
Center to Flange avg:30.8
Spoke Hole: 2.5
Spokes: 32
Cross: 3x

I'm pretty sure your problem has to do with your lacing. I think your lacing pattern is probably not right. I would unlace the wheel and do it again. I did the same thing before.

 

[guerrero101]

Sorry to jump in but I have a question. Antonio gave individual measurements for left and right Center to Flange, and CupOfJava averaged those measurements and gave a single spoke length. Is that the best way of doing it or would it be best to order different sizes for left and right side hub?

 

[CupOfJava]

If you can afford buying two different spoke lengths that would work too. I found even at 5mm difference the spokes still work. I probably would stay within + or - 3mm. Obviously the more precise the better.

 

[nicolicious]

sounds like....

sounds like you did a 2 cross pattern instead of 3.... i did the same thing and the spokes were going through the nipples and nothing was tight....

unlace and try again .....

 

[jeffj]

Just a shot in the dark. . . . .

Are you certain you have 12mm nipples (and not something like 16mm nipples)?

A pic would truly be worth 1,000 words here.

My calcs show 263mm (L) and 264mm (R).

 

[shiggy]

Sorry to jump in but I have a question. Antonio gave individual measurements for left and right Center to Flange, and CupOfJava averaged those measurements and gave a single spoke length. Is that the best way of doing it or would it be best to order different sizes for left and right side hub?

No, averaging the flange spacing is a terrible way to do it. For a good, solid wheel build the spoke length needs to be +/-1.5mm from ideal. You MIGHT be able to lace and tension a wheel with more of a difference but I would not trust it to be durable or reliable.

 

[meltingfeather]

sounds like you did a 2 cross pattern instead of 3.... i did the same thing and the spokes were going through the nipples and nothing was tight....

unlace and try again .....

this sounds like the most likely scenario to me. post a pic?

 

[CupOfJava]

No, averaging the flange spacing is a terrible way to do it. For a good, solid wheel build the spoke length needs to be +/-1.5mm from ideal. You MIGHT be able to lace and tension a wheel with more of a difference but I would not trust it to be durable or reliable.

you're probably right. I was thinking since it was the front wheel it wouldn't matter as much if I averaged the two sides. For the rear wheel it would definitely make a huge difference. And I'm probably a little too generous with lengths. I would say you don't want to be more than 1.5 mm short, and being too long could cause you to pop a tube.

 

[wyrm]

I usually order the longer of the two lengths... and Phil Wood takes care of the rest. No wasted spokes that way.

 

[shiggy]

you're probably right. I was thinking since it was the front wheel it wouldn't matter as much if I averaged the two sides. For the rear wheel it would definitely make a huge difference. And I'm probably a little too generous with lengths. I would say you don't want to be more than 1.5 mm short, and being too long could cause you to pop a tube.

It is a front disc hub with an 11mm flange spacing difference! Of course it will make a difference.

Also, if the spokes are too long the threads bottom out before you reach proper tension. I had to rebuild a wheel with shorter spokes after I trusted somebody else to pick the lengths for me. I was barely able to reach an acceptable tension but it would not stay true and I had not threads left to fix it.

 

[antonio]

sounds like you did a 2 cross pattern instead of 3.... i did the same thing and the spokes were going through the nipples and nothing was tight....

unlace and try again .....

:thumbsup:

Nicolicious hit the nail on the head.

Thanks for all the good info.

 

[CupOfJava]

Based on my numbers the spoke length should be: 263.7mm

ERD: 544
Flange Diameter: 52
Center to Flange avg:30.8
Spoke Hole: 2.5
Spokes: 32
Cross: 3x

I'm pretty sure your problem has to do with your lacing. I think your lacing pattern is probably not right. I would unlace the wheel and do it again. I did the same thing before.

I think CupofJava nailed it on the head..

 

[antonio]

Oops. Sorry, I scanned through the thread quickly and missed your earlier response. Thanks CoJ.

 

[shiggy]

Ok I'm new to MTBR and apologize for not being a good searcher. I tried but don't want to spend 4 hours trying to find the right thread to ask my question. Please forgive me.

Here is my problem and help would be awesome. I have a rear Chris King 135 ISO hub that has DT comp 2/1.8/2 spokes lacing an EX500 rim 32 hole. It was built by a shop and thought they did a good job. I have since ran out of threads to tighten the Drive side. I thought they just used too long of spokes. I pulled one drive side spoke and one non drive side spoke measured them and they are what is recommended by the DT spoke calc.

My first few questions are on ERD, since the wheel is already built and the ERD I used in the DT spoke calc is 539 from DT's web site, should I measure it myself to see if it is out of wack? Should I take the wheel apart to use spokes to measure the ERD?

Since the spokes are the size recommended assuming the ERD is correct why am I having problems now?

I should say that the only spokes I’m not running out of threads on are the “head in” spokes on the non drive side. That does make since to me as they are going to need to be slightly longer because they have to bend around the flange.

Here is the measurements I have and I believe they are accurate.
Axle 135mm QR
ERD 539 (from DT's website)
spoke hole dia.2.5
center to DS flange 20.1
center to non DS flange 33.9
flange dia. 57.4
spoke DS 260mm (this is the actual spoke length)
spoke non DS 261.5 (this is the actual spoke length)
12mm alum nipples
3 cross

The calculations I come up with are259 and 261 about 1mm shorter then what is in there, will that be enough for future trueing? Or should I consider 258 and 260?

I’m by no means a wheel builder but I would not think it should be so difficult.

Welcome to the art and experience part of wheelbuilding. This is why most of us here will not provide spoke lengths.

I have used spokes, nipples, hubs and rims--all provided by a top level builder--where the spokes were slightly too long for the way I build my wheels. Needed to rebuild with shorter spokes.

Learn learned. I only trust my own caluculations

 

[WillTheGreat]

If you use 1mm shorter spokes, this should enable you to tighten the nipples by 2 more full turns.

I have had good results using the DT Swiss calculator, but I have always used DT Swiss spokes, nipples, and rims. I recommend verifying your hub measurements yourself. Misprinted dimensions are not unheard of.

 

[meltingfeather]

I want to be able to quantify what I'm doing with a spoke calc for future refrence. There may be a day when I need to build more wheels.

Are you using 12mm nipples?

What is the consensus with where the spoke should end? I have heard at the screw driver flat and the top of the nipple. Being at the top of the nipple doesn't leave much room for adjustment. I can under stand why some have said this as it supports the head of the nipple for heavy loads. However having adjustment is just as important if not more then a little support. Would it make since to end the spoke half way up from the landing of the screw slot? Or at least shoot for that spot.

Ideally the spokes should end up between the bottom of the slot and the top of the nipple.
With DT Swiss spokes and 12mm nipples the spokes won't bottom out until ~2mm of spoke is protruding past the head of the nipple, which is more than enough room for any future adjustment.

 

[meltingfeather]

Yes, 12mm alum nipples.



I'm using what I think is DT nipples but see no markings to confirm this. The spokes are for sure DT 2/1.8/2. When I thread a nipple on to a spoke out of the wheel only 1mm comes out of the top. Am I missing something?

Nah. I was just going off of recollection. 1mm is probably right. You said the wheel was built by a shop, right? What was wrong with it that you're messing with it?
If spokes are sticking that far out of nipples you've either made a lacing error (if you laced it) or the ERD is off by ~4mm or so. DT ERDs are usually good.

 

[shiggy]

Don't be condescending to people. :nono:

I am not. Just stating the facts.

 

[meltingfeather]

I measured ERD and got 537.5mm There's the problem!

DT lists it as 539mm on the website and 540mm on the rim.

The wheel was built with 259mm and 261mm spokes. The shop must have used the measurement DT provided.

Calc now says 258mm and 260mm spokes, one mm shorter on each, I'm happy with that and will go buy them today.

Thanks for the help guys.

How did you measure it?
If you did it this way (click Rims, then Measuring Rims), I'm surprised you got something different from DT's published spec. The DT Swiss spoke calculator also describes how to do it in the spoke calculator Help tab (link). It's in the second bullet, second set of bullets.
The DT Swiss ERDs are usually dead on.
If you are bottoming out threads, you probably want more than 1.0mm shorter, especially since manufacturing tolerance on spoke length seems to be about (+/-)0.5mm in my experience.