Go Back  Bike Forums > Bike Forums > Bicycle Mechanics
Reload this Page >

First attempt at wheel build - FAIL

Notices
Bicycle Mechanics Broken bottom bracket? Tacoed wheel? If you're having problems with your bicycle, or just need help fixing a flat, drop in here for the latest on bicycle mechanics & bicycle maintenance.

First attempt at wheel build - FAIL

Old 09-04-10, 04:58 PM
  #1  
Junior Member
Thread Starter
 
Join Date: Jul 2010
Location: Florida's Space Coast
Posts: 11

Bikes: n/a

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
First attempt at wheel build - FAIL

The spoke threads bottom out on the nipples and the wheel won't tension. The spokes are too long, right?

I used the spocalc spreadsheet and two online spoke length calculators - same length calculated by them all using published data for the rim and hub in a cross 3 design. (Salsa Semi 29r Disc and Surly New Disc front). Rounded up to the nearest mm (so says Sheldon) and ordered them.

Built the wheel and attempted to tension it. After looking at a floppy wheel for a while I measured the six spares I bought - all were 2 mm too long. I measured these from the center of the head of the spoke to the end of the threads. Then I measured the uninstalled set I bought for the rear - every spoke is 2 mm too long.

The cumulative error is 4 mm across the wheel diameter. Is the length that critical? Perhaps I should have rounded down rather than up (what the DT Swiss calculator does).

My spokes were cut to order using a DT Swiss spoke machine. How closely does the length of the DT Swiss boxed spokes compare to the indicated length?

-- Bradley
Bradley P is offline  
Old 09-04-10, 05:54 PM
  #2  
Senior Member
 
Join Date: Dec 2009
Posts: 4,700
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 5 Times in 4 Posts
If the spoke threads are bottoming out in the nipples, yeah that 4mm across is that critical. Also check your lacing pattern very closely to be sure - you may have done a 2-cross instead of a 3-cross, or something else weird.

One idea if you're using long nipples is to try shorter ones. But too much spoke through the bottom of the nipple could poke holes in your tube.
achoo is offline  
Old 09-04-10, 06:16 PM
  #3  
Senior Member
 
Mark Kelly's Avatar
 
Join Date: Oct 2009
Location: Willy, VIC
Posts: 644
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by Bradley P
- all were 2 mm too long. I measured these from the center of the head of the spoke to the end of the threads.

-- Bradley
That is not the way to measure spoke length. The quoted length of a spoke is from the end of the threads to the inside of the bend.

The most common cause of your problem is that the ERD you used is not the correct one. Always measure it yoruself, never trust specifications.
Mark Kelly is offline  
Old 09-04-10, 06:20 PM
  #4  
Senior Member
 
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 38,546

Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter

Mentioned: 139 Post(s)
Tagged: 1 Thread(s)
Quoted: 5703 Post(s)
Liked 2,434 Times in 1,346 Posts
Show me someone who's never had spokes come out too long or too short, and I'll show you someone who hasn't built many wheels. Sorry it happened on your first wheels, but even if you do everything right it might happen again.

It's important that you use spoke calculators carefully, and make sure all the data you enter is correct. The direction to round will vary with the calculator, because some give you length to near the top of the nipple head, and some toward the bottom. It's good to stay with the same calculator because you'll get used to it's bias, and can factor it in.

Also be careful about data entered, for example rim diameters (ERD). I prefer to measure them myself, finding some mfrs. specs to be off. Mixing brands of spokes and nipples can also create surprises. Most spokes and nipples of the same brand will allow the nipple to thread until the spoke is about 2mm beyond the top, giving you some margin for error.

At this stage, I'd recheck all your data and recheck the calculation. Then I'd measure everything and see if you can discover where you went wrong. If everything is consistent, then make a note of how far off you came out, and factor that in next time. BTW- spokes are measured from the inside of the elbow to the end, not from the center of the bend. It's a difference of 1mm, but when you're at the edge of tolerance a millimeter is as good as a mile.
__________________
FB
Chain-L site

An ounce of diagnosis is worth a pound of cure.

Just because I'm tired of arguing, doesn't mean you're right.

“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN

WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FBinNY is online now  
Old 09-04-10, 06:44 PM
  #5  
Senior Member
 
mrrabbit's Avatar
 
Join Date: Dec 2007
Location: San Jose, California
Posts: 3,504

Bikes: 2001 Tommasini Sintesi w/ Campagnolo Daytona 10 Speed

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 145 Post(s)
Likes: 0
Liked 35 Times in 30 Posts
At 32 Hole 3-cross I get 292.50mm / 293.38 which rounds out to 292mm and 293mm.

At 36 Hole 3-cross I get 288.97mm / 289.86 which rounds out to 289mm and 290mm.

Those would work with 12mm nipples and probably be borderline okay with 14mm nipples...

What were your measurements?

=8-)
__________________
5000+ wheels built since 1984...

Disclaimer:

1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:

Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
mrrabbit is offline  
Old 09-04-10, 07:18 PM
  #6  
Junior Member
Thread Starter
 
Join Date: Jul 2010
Location: Florida's Space Coast
Posts: 11

Bikes: n/a

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by mrrabbit
At 32 Hole 3-cross I get 292.50mm / 293.38 which rounds out to 292mm and 293mm.

At 36 Hole 3-cross I get 288.97mm / 289.86 which rounds out to 289mm and 290mm.

Those would work with 12mm nipples and probably be borderline okay with 14mm nipples...

What were your measurements?

=8-)
I got the same figures for the 32H and rounded up to 293mm and 294mm. Nipples are DT 12mm. I'll attempt to measure ERD tomorrow on a virgin rim using the DT nipples. The bit about measuring spoke length from the inside of the bend should be fine as long as the spoke length calculators determine spoke length from the periphery of the spoke hole in the hub to the ERD dimension rather than from the center of the hole. I expect they do because the hub's spoke hole diameter is a driving dimension.
Bradley P is offline  
Old 09-04-10, 08:03 PM
  #7  
Senior Member
 
mrrabbit's Avatar
 
Join Date: Dec 2007
Location: San Jose, California
Posts: 3,504

Bikes: 2001 Tommasini Sintesi w/ Campagnolo Daytona 10 Speed

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 145 Post(s)
Likes: 0
Liked 35 Times in 30 Posts
One of the following probably happened:

A. You have the right size spokes - you just laced 2X instead of 3X without realizing it...

OR

B. The person operating the Phil Wood spoke machine mis-read the ruler - i.e., read the markings to quickly and place it at 298mm instead of 293mm when cutting and rolling.

("B" has happened to me at least a dozen times in 20+ years...often when someone was rushing me...)

=8-)
__________________
5000+ wheels built since 1984...

Disclaimer:

1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:

Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
mrrabbit is offline  
Old 09-05-10, 10:03 AM
  #8  
Junior Member
Thread Starter
 
Join Date: Jul 2010
Location: Florida's Space Coast
Posts: 11

Bikes: n/a

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
I measured ERD at two spots 90 deg apart on the new rim and got 606. Salsa claims 605. This was measured by taking two of the spokes that measure 295mm from thread tip to bend, inserting them into diametrically opposed holes and threading them fully on to the nipples. I pulled them tight and measured across the two bends, about 16mm.

The wheel is threaded as a X3. If it were threaded as a X2 there would be 10mm of spokes poking out.

I think I see what is going on here. If everything were perfect, ERD as specified and spokes cut to the ideal length, the wheel would go into tension just at the point that the ends of the spokes became flush with the ends of the nipples.

I rounded spoke length up and they were fabricated 1mm longer than spec so my spokes are about 1.5mm too long. With everything perfect I would need to be able to tighten such that about 1.5mm of spoke protruded beyond each nipple to tension the wheel. The spokes and nipples both have 9mm of thread; it is not possible to tighten the spokes to where there is 1.5mm protruding from the nipple - only flush or slightly beyond.

It seems to me that to allow for tolerances in spoke fabrication, and to allow tension to occur before the spoke protrudes from the nipple, spoke length should be specified as less than the ideal by perhaps 2mm. That still would allow 6-7mm of thread engagement under worse case tolerance stack up. OTOH, were these spokes cut to the requested length, and had I rounded down I think this wheel would have come into tension.
Bradley P is offline  
Old 09-05-10, 10:10 AM
  #9  
Banned
 
Join Date: Jun 2010
Location: NW,Oregon Coast
Posts: 43,598

Bikes: 8

Mentioned: 197 Post(s)
Tagged: 0 Thread(s)
Quoted: 7607 Post(s)
Liked 1,354 Times in 861 Posts
LBS uses a DT published wall chart like page, to lay the rim onto, got their help since my Sutherlands data
is missing a lot of rims made since that edition was published.

I have a DT spoke ruler, you hook the spoke over the hole in it.
zero is the edge of that hole


I found some Pop-rivet washers in aluminum same hole size as the one in the rims

maybe a kludge there, for your spoke overlength situation..

Last edited by fietsbob; 09-05-10 at 10:17 AM.
fietsbob is offline  
Old 09-05-10, 10:49 AM
  #10  
Senior Member
 
vredstein's Avatar
 
Join Date: Aug 2008
Location: Tucson, Arizona
Posts: 704

Bikes: '02 Lemond Buenos Aires, '98 Fuji Touring w/ Shimano Nexus premium, '06 Jamis Nova 853 cross frame set up as commuter, '03 Fuji Roubaix Pro 853 back up training bike

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 1 Time in 1 Post
Originally Posted by Bradley P
I measured ERD at two spots 90 deg apart on the new rim and got 606. Salsa claims 605. This was measured by taking two of the spokes that measure 295mm from thread tip to bend, inserting them into diametrically opposed holes and threading them fully on to the nipples. I pulled them tight and measured across the two bends, about 16mm.

The wheel is threaded as a X3. If it were threaded as a X2 there would be 10mm of spokes poking out.

I think I see what is going on here. If everything were perfect, ERD as specified and spokes cut to the ideal length, the wheel would go into tension just at the point that the ends of the spokes became flush with the ends of the nipples.

I rounded spoke length up and they were fabricated 1mm longer than spec so my spokes are about 1.5mm too long. With everything perfect I would need to be able to tighten such that about 1.5mm of spoke protruded beyond each nipple to tension the wheel. The spokes and nipples both have 9mm of thread; it is not possible to tighten the spokes to where there is 1.5mm protruding from the nipple - only flush or slightly beyond.

It seems to me that to allow for tolerances in spoke fabrication, and to allow tension to occur before the spoke protrudes from the nipple, spoke length should be specified as less than the ideal by perhaps 2mm. That still would allow 6-7mm of thread engagement under worse case tolerance stack up. OTOH, were these spokes cut to the requested length, and had I rounded down I think this wheel would have come into tension.
With this simple 1.5mm length error, and still no built wheel to show for it, you learned a whole lot more than you would have if everything had just fallen into place. Wheelbuilding is one of the best examples of an activity where you learn more, and a whole lot faster from your mistakes than from your successes.
vredstein is offline  
Old 09-05-10, 11:36 AM
  #11  
Senior Member
 
mrrabbit's Avatar
 
Join Date: Dec 2007
Location: San Jose, California
Posts: 3,504

Bikes: 2001 Tommasini Sintesi w/ Campagnolo Daytona 10 Speed

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 145 Post(s)
Likes: 0
Liked 35 Times in 30 Posts
Phil Wood and Kowa spoke machines cut 10mm of threads - and in your case 12mm nipples and 14mm nipples would have worked.

However you mentioned use of DT Swiss spoke machine? With 9mm threads? 12mm nipples might take up the slack and stop at the top - but don't think 14mm nipples will work.

Good Luck!


=8-)
__________________
5000+ wheels built since 1984...

Disclaimer:

1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:

Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
mrrabbit is offline  
Old 09-05-10, 02:48 PM
  #12  
Junior Member
Thread Starter
 
Join Date: Jul 2010
Location: Florida's Space Coast
Posts: 11

Bikes: n/a

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by vredstein
With this simple 1.5mm length error, and still no built wheel to show for it, you learned a whole lot more than you would have if everything had just fallen into place. Wheelbuilding is one of the best examples of an activity where you learn more, and a whole lot faster from your mistakes than from your successes.
Yup. An expensive lesson and I don't think it is over yet - I have to buy more spokes.

Originally Posted by mrrabbit
<snip> However you mentioned use of DT Swiss spoke machine? With 9mm threads? <snip>
I was wrong. I check the site and they use a "Philwood spoke cutting and threading machine."
Bradley P is offline  
Old 09-05-10, 03:03 PM
  #13  
Senior Member
 
Join Date: Feb 2005
Location: Oklahoma
Posts: 9,438

Bikes: Trek 5500, Colnago C-50

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Likes: 0
Liked 7 Times in 6 Posts
Another case of why I say to always round down.
Al1943 is offline  
Old 09-05-10, 03:47 PM
  #14  
Senior Member
 
mrrabbit's Avatar
 
Join Date: Dec 2007
Location: San Jose, California
Posts: 3,504

Bikes: 2001 Tommasini Sintesi w/ Campagnolo Daytona 10 Speed

Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 145 Post(s)
Likes: 0
Liked 35 Times in 30 Posts
Originally Posted by Al1943
Another case of why I say to always round down.
Agree 99%

Some manus like Mavic aim exactly for the screwdriver flat. So as-is is fine with their ERDs. But most others aim somewhere between the screwdriver flat and the top of the nipple - so rounding down gets you right back to the screwdriver flat.

Recently when Sun-Ringle put out their MTX33's, they reported on the rim labels ERD's of 536 and 598. I knew right away when measuring and after building a dozen that someone had measured all the way to the top of the nipple. Called 'em, they already knew and had already corrected their documentation. (They still insist on 597mm for the 700c though...)

Luckily, rounding down on the first set of rims kept me out of trouble by a hair. I use 534 and 596 - as-is - perfect result everytime.

Also, rounding down makes the use of 14mm nipples more feasible as an option...

=8-)
__________________
5000+ wheels built since 1984...

Disclaimer:

1. I do not claim to be an expert in bicycle mechanics despite my experience.
2. I like anyone will comment in other areas.
3. I do not own the preexisting concepts of DISH and ERD.
4. I will provide information as I always have to others that I believe will help them protect themselves from unscrupulous mechanics.
5. My all time favorite book is:

Kahane, Howard. Logic and Contemporary Rhetoric: The Use of Reason in Everyday Life
mrrabbit is offline  
Old 09-05-10, 05:25 PM
  #15  
Senior Member
 
Join Date: Feb 2005
Location: Oklahoma
Posts: 9,438

Bikes: Trek 5500, Colnago C-50

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Likes: 0
Liked 7 Times in 6 Posts
Originally Posted by mrrabbit
Agree 99%
Rounding down also helps offset spoke stretch, from my experience spokes that are double butted to 1.5 mm can definitely stretch on the drive side rear under normal high tension.
Al1943 is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Gerryattrick
Bicycle Mechanics
4
03-12-16 02:28 PM
Gerryattrick
Bicycle Mechanics
14
01-07-16 09:51 AM
Chris Chicago
Bicycle Mechanics
8
03-16-15 11:17 PM
eggnog
Bicycle Mechanics
22
11-16-11 10:33 PM

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.