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

Spoke Length variance allowed?

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.

Spoke Length variance allowed?

Old 01-04-10, 06:41 PM
  #1  
Road cyclist
Thread Starter
 
Join Date: Aug 2009
Location: Ireland
Posts: 29

Bikes: Trek 400, Raleigh Panasonic, Barracuda Magma

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Spoke Length variance allowed?

Hi,

Having built a few 3 cross wheels I wanted to try something different just for the fun of it.

I've got a pretty sweet price on some 290mm spokes, the front wheel is 32h, want to lace it 2 leading 2 trailing, and the rear is 36h, want to lead it 3 leadng 3 trailing.

Now, i've calculated the front to need 290.6mm spokes, so they'll be fine, but the back requires 292.6mm.

This on either side add's up to 5mm of a difference.

Will I be able to use 290mm spokes on the 36h wheel that requires 292.6mm? I'm using standard. 12mm nipples that protrude roughly 6.5mm out of the rim.

The spokes are threaded for around 10mm at the end of the spoke.

Hope this is enough info,
Cheers,
Paul
Pir0 is offline  
Old 01-04-10, 07:18 PM
  #2  
headtube.
 
zzyzx_xyzzy's Avatar
 
Join Date: Sep 2008
Posts: 803
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 3 Times in 3 Posts
If it's a really good deal on 290 spokes it could work if you get 14mm nipples for the rear wheel. Otherwise you might not engage enough of the threads inside the nipple.
zzyzx_xyzzy is offline  
Old 01-04-10, 07:29 PM
  #3  
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
I think they'll be fine.
Al1943 is offline  
Old 01-04-10, 08:48 PM
  #4  
cab horn
 
Join Date: Jun 2004
Location: Toronto
Posts: 28,353

Bikes: 1987 Bianchi Campione

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 42 Post(s)
Likes: 0
Liked 25 Times in 18 Posts
Originally Posted by Pir0
Hi,

Having built a few 3 cross wheels I wanted to try something different just for the fun of it.

I've got a pretty sweet price on some 290mm spokes, the front wheel is 32h, want to lace it 2 leading 2 trailing, and the rear is 36h, want to lead it 3 leadng 3 trailing.

Now, i've calculated the front to need 290.6mm spokes, so they'll be fine, but the back requires 292.6mm.

This on either side add's up to 5mm of a difference.

Will I be able to use 290mm spokes on the 36h wheel that requires 292.6mm? I'm using standard. 12mm nipples that protrude roughly 6.5mm out of the rim.

The spokes are threaded for around 10mm at the end of the spoke.

Hope this is enough info,
Cheers,
Paul
No.

If you've measured everything right, it's +/- 1mm tolerance. 290's will not work for a 292.6 (293). You will have little to zero tension on the rear, left side. Even if you tried to compensate by overtensioning the rear drive side. Do not do this.
operator is offline  
Old 01-05-10, 10:03 AM
  #5  
Road cyclist
Thread Starter
 
Join Date: Aug 2009
Location: Ireland
Posts: 29

Bikes: Trek 400, Raleigh Panasonic, Barracuda Magma

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
I forgot to mention the rear hub is a single speed hub with equal diameter flanges. The same distance from the centre.

I understand you need 2 different sized spokes for freewheel hubs and freehubs. But this is a fixed fixed hub, so it's symetrical.

Reckon it'd be alright now?
Pir0 is offline  
Old 01-05-10, 10:29 AM
  #6  
Road cyclist
Thread Starter
 
Join Date: Aug 2009
Location: Ireland
Posts: 29

Bikes: Trek 400, Raleigh Panasonic, Barracuda Magma

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Pir0
I forgot to mention the rear hub is a single speed hub with equal diameter flanges. The same distance from the centre.

I understand you need 2 different sized spokes for freewheel hubs and freehubs. But this is a fixed fixed hub, so it's symetrical.

Reckon it'd be alright now?
Here's a pic I made as I do with all the wheelbuilds I do to keep me right,


(Btw the flange diameter in this IS measured centre to centre of opposite holes, not to the edge as pictured, that's just a quick template I made.)
The rim has an ERD of 608mm
Pir0 is offline  
Old 01-05-10, 10:35 AM
  #7  
cab horn
 
Join Date: Jun 2004
Location: Toronto
Posts: 28,353

Bikes: 1987 Bianchi Campione

Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 42 Post(s)
Likes: 0
Liked 25 Times in 18 Posts
There is no way that blue measurement is 135mm. It doesn't even include either cone/locknut on BOTH sides. That hub would fit on NO bike. And again, 290 will not work on a spoke length spec'ed for 293, regardless if it's dishless.

Last edited by operator; 01-05-10 at 10:41 AM.
operator is offline  
Old 01-05-10, 11:35 AM
  #8  
nice idea, poor execution
 
Join Date: Oct 2009
Location: West Newton, MA
Posts: 397
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 2 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
That's not the only thing wrong with that picture.
helicomatic is offline  
Old 01-05-10, 01:46 PM
  #9  
Road cyclist
Thread Starter
 
Join Date: Aug 2009
Location: Ireland
Posts: 29

Bikes: Trek 400, Raleigh Panasonic, Barracuda Magma

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Regardless of the picture, the measurements I've taken are fine i made that in a hurry and clearly misplaced some of the lines.

So on a dishless wheel with a symmetrical hub, 290mm spokes wont work with 12mm nipples, for a wheel i've calculated needs 292.6mm spokes? And there's no way around it other than to get 292mm or 293mm spokes?

Is it better to round up to the nearest whole number than round down?
Pir0 is offline  
Old 01-05-10, 03:13 PM
  #10  
Useful Idiot
 
cincy_14's Avatar
 
Join Date: Jul 2006
Location: Butler, OH
Posts: 25

Bikes: Giant RS940, Schwinn Sports Tourer

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Originally Posted by Pir0
Regardless of the picture, the measurements I've taken are fine i made that in a hurry and clearly misplaced some of the lines.

So on a dishless wheel with a symmetrical hub, 290mm spokes wont work with 12mm nipples, for a wheel i've calculated needs 292.6mm spokes? And there's no way around it other than to get 292mm or 293mm spokes?

Is it better to round up to the nearest whole number than round down?
292 is the shortest length I would use on your rear wheel. Longer nipple will not help you, as I don't believe they have any longer threads.

You can round up or down depending on your ERD measurement. When I use the manufacturer's ERD I usually round down and when I measure the ERD myself to the bottom of the nipple screwdriver slot I round up. Rounding down by 2.6mm is too much IMO.
cincy_14 is offline  
Old 01-05-10, 03:15 PM
  #11  
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
It's always better to round down to avoid running out of threads. This is more important on wheels on rear wheels with high driveside tension.
Al1943 is offline  
Old 01-05-10, 05:16 PM
  #12  
Retro-Direct Fan
 
TwoShort's Avatar
 
Join Date: Aug 2007
Location: Boulder, Colorado
Posts: 159
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Generally, one would calculate the optimal length, then round to the nearest available spoke length. Depending upon the obscurity of your length requirement & spoke type & the extensiveness of your suppliers inventory, this will generally mean rounding by less than a mm, but sometimes more. 2mm off is about the maximum that would typically ever be required, and I 'd generally recommend against exceeding it.

On the other hand, you'll probably be fine. They'll reach, but you'll have a bit less thread engagement than is optimal; slightly more chance of breaking a spoke. You're going 3-leading, 3-trailing, so obviously "optimal" is not the target.

I have build very nice 3-cross wheels where I wouldn't have dreamed of being off by 2.6. I have also laced the cheapest spokes I could find to a beat-up coaster hub in the very 3&3 pattern you describe. I say, go for it.
TwoShort is offline  
Old 01-05-10, 05:21 PM
  #13  
Senior Member
 
Join Date: Feb 2009
Posts: 6,660
Mentioned: 16 Post(s)
Tagged: 0 Thread(s)
Quoted: 582 Post(s)
Liked 171 Times in 138 Posts
You can do just fine with 3mm short. It just isn't the Sunday-go-to-meeting way to go.
davidad is offline  
Old 01-05-10, 10:13 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
Nope...wouldn't do it...don't use nipples as a spokes...nipple barrels will eventually break...unless you are certain that the spoke ends are getting into the rim a mm or so after final tension.

Also if those spokes are DT or Ritchey...I wouldn't be surprised if they came out of the box measuring 289.5 mm...leftover stocks of DT and Ritchey spokes from the 80s and 90s still show up with spokes .5mm under the box labelled size.

Check with a Park Tool or Wheelsmith spoke ruler...

=8-)
mrrabbit is offline  
Old 01-05-10, 10:54 PM
  #15  
Senior Member
 
Yan's Avatar
 
Join Date: Jan 2006
Posts: 2,878
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 1840 Post(s)
Liked 583 Times in 404 Posts
This link says that spokes for 3 leading 3 trailing wheels should be 1-2 mm longer than required, because the extra lacing in this pattern takes up a bit of length. I think 2.5mm short would normally be fine, but maybe not in this case. I have never built a wheel in this pattern.
Yan is offline  
Old 01-06-10, 06:19 AM
  #16  
Road cyclist
Thread Starter
 
Join Date: Aug 2009
Location: Ireland
Posts: 29

Bikes: Trek 400, Raleigh Panasonic, Barracuda Magma

Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Likes: 0
Liked 0 Times in 0 Posts
Thanks a lot for the advice guys. 290mm is a pretty sure length to buy though, I've used them before and now again, so i'm sure i'll use them in future.

I think I would need longer spokes for the rear after reading some, it just means I'll probably end up buying some cheapo spokes cut to length instead of the double butted oens I wanted, but then again, as I said, I'm only doing this for a bit of fun and for a change. As for 3leading 3 trailing needing longer spokes, Iknow quite a few guys who have bought standard 3 cross cheap wheels and re laced them for the fun of it with no problems due to spoke length.

As was said, i'm not going for the best wheel I can build I just want a little project to work at over the break. I think I'll still get the 290mm spokes for the front and see what I can get in the mean time for the back and keep an eye out for some better spokes, and if they're cheap enough get them and relace the whee, no harm done.



Again, thanks a lot for the info guys, much appreciated,
Cheers,
Paul
Pir0 is offline  
Old 01-07-10, 05:07 AM
  #17  
Senior Member
 
Join Date: Mar 2008
Posts: 8,688
Mentioned: 46 Post(s)
Tagged: 0 Thread(s)
Quoted: 1074 Post(s)
Liked 295 Times in 222 Posts
Originally Posted by Pir0
... 290mm spokes wont work with 12mm nipples, for a wheel i've calculated needs 292.6mm spokes? And there's no way around it other than to get 292mm or 293mm spokes?
I might try that build if it was parts that I had on hand, but I wouldn't buy parts with such poor odds of fitting. You're basically trading out all your margin of error in the first round.

I 've had no problems compensating for shorter spokes with longer nipples though.
dabac is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
tmh657
Bicycle Mechanics
22
07-23-14 07:54 PM
mosef45
Bicycle Mechanics
21
03-29-13 05:33 PM
serpico7
Bicycle Mechanics
24
06-16-11 04:21 PM
constant mesh
Bicycle Mechanics
7
09-01-10 06:02 AM
nymtber
Bicycle Mechanics
6
03-22-10 06:37 AM

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.