HOT: Active* forum members generally gain 5% discount at starbike.com store!
Weight Weenies
* FAQ    * Search    * Trending Topics
* Login   * Register
HOME Listings Articles FAQ Contact About




Post new topic Reply to topic  [ 11 posts ] 
Author Message
PostPosted: Sun Apr 21, 2013 4:21 pm 
Offline

Joined: Sun Apr 21, 2013 4:09 pm
Posts: 4
I built a front wheel with a BHS light weight front hub, a Kinlin XR200 rim, and 24 sapim laser spokes, laced radially, elbows in.

I have I'd guess between 3 and 5k miles on this wheel and just busted a spoke, which made for an unpleasant ride home since the wheel went very far out of true.

The wheel was built with a tension meter and the tension was not perfect but within 15kgf either way of 110kgf. I weigh 160lb and am riding on mixed roads.

I replaced the spoke and retrued the wheel but its got me a bit concerned that it will happen again. The rim was not perfect to begin with and the tension is about as even as I can get it while maintaining trueness. You guys think I'm going to continue busting spokes?


Top
 Profile  
 
PostPosted: Sun Apr 21, 2013 4:49 pm 
Offline
Shop Owner
User avatar

Joined: Mon Jan 14, 2013 5:45 pm
Posts: 353
Location: UK
lightweight = reduced strenght, even if built well the wheels will never be bombproof.

_________________
Madone Five Series 2013
Shimano Dura-Ace 9000
Mavic Cosmic SLE 2013


Top
 Profile  
 
Posted: Sun Apr 21, 2013 4:49 pm 


Top
  
 
PostPosted: Sun Apr 21, 2013 5:42 pm 
Offline

Joined: Thu Jan 17, 2013 3:25 pm
Posts: 28
Where did the spoke break (near elbow, near nipple)? Can you take a photo?


Top
 Profile  
 
PostPosted: Sun Apr 21, 2013 5:50 pm 
Offline

Joined: Mon Feb 04, 2013 10:04 pm
Posts: 54
If it broke at the thread or mid span, it was a defective spoke. If it broke at the elbow, did you stress relieve it when you built it?


Top
 Profile  
 
PostPosted: Sun Apr 21, 2013 6:40 pm 
Offline

Joined: Sun Apr 21, 2013 4:09 pm
Posts: 4
bobqzzi wrote:
If it broke at the thread or mid span, it was a defective spoke. If it broke at the elbow, did you stress relieve it when you built it?


It broke at the elbow, yes, I stress relieved by grabbing spokes when I built it.

For a lightweight wheel like this, what's the max variation in spoke tension you'd accept?


Top
 Profile  
 
PostPosted: Sun Apr 21, 2013 6:56 pm 
Offline

Joined: Mon Feb 04, 2013 10:04 pm
Posts: 54
10% or so maybe a little more for the ones at the joint. Are you saying that this one was from 95 to 125? That's quite a bit.


Top
 Profile  
 
PostPosted: Sun Apr 21, 2013 9:07 pm 
Offline
in the industry

Joined: Sat May 12, 2012 7:25 pm
Posts: 1329
Location: Glermsford, Suffolk U.K
Yes your tesnion variation is too high. 15 kgf is about 150N that is way too much more than 10%. I build with these rims and no more than 5% variation in tension is possible around the average. That will improve spoke life alot as I bet it was a low tension spoke that broke. Unfortunatley you did a poor build. Rebuild with new spokes and work on getting more even tension. max (often less) 5% variation and no more than 0.3mm rondness variation is what I look for when building with this rim. Even tesnion is more important than how round the wheel is anyway.

It is easy to get a wheel with 0.1 mm lateral trueness

_________________
www.thecycleclinic.co.uk


Last edited by bm0p700f on Mon Apr 22, 2013 9:14 am, edited 1 time in total.

Top
 Profile  
 
PostPosted: Mon Apr 22, 2013 12:18 am 
Offline

Joined: Sun Jan 01, 2012 9:58 am
Posts: 267
+/- 15 with lasers is a big range. with a park tm-1 that's like having spokes spread across 3 or 4 readings which is a pretty big difference.

i second the notion to re-build. 24x lasers will only cost you ~$30 and a bit of your time to improve your building skills and also make a more reliable wheel.


Top
 Profile  
 
PostPosted: Mon Apr 22, 2013 3:14 am 
Offline
in the industry
User avatar

Joined: Sun Jul 29, 2012 2:59 pm
Posts: 631
Location: Ruidoso, NM
peligro wrote:
It broke at the elbow, yes, I stress relieved by grabbing spokes when I built it.


Grabbing spokes isn't enough IMO. Did the wheel stay true from the start?

You said 110+-15kg... way too much variation. Try 95+-5kg. Shoot for .010" radial variance and .005" lateral. I've built a lot of them. Front wheels just don't need a lot of tension, and you should not need that much variance unless the rim is bent. Even tension is more important than getting it perfectly true. And mark the spokes for windup.

And take a spoke wrench with you... my multi tool has one. I can't remember the last time I broke a spoke, but I've fixed other people's wheels...

BTW... I have >10k miles on a set of XR200s with 20f @170 lbs and no issues until I slammed into a pothole and dented the rim...

_________________
formerly rruff...


Top
 Profile  
 
PostPosted: Mon Apr 22, 2013 7:14 pm 
Offline

Joined: Sun Apr 21, 2013 4:09 pm
Posts: 4
Thanks for the replies, appreciate the advice.


Top
 Profile  
 
PostPosted: Mon Apr 22, 2013 8:44 pm 
Offline

Joined: Tue Nov 11, 2003 9:47 pm
Posts: 1712
Location: Santa Cruz, California, USA
I had some break like that on my UL hub.

Try lacing heads in.

The BHS UL hub has large chamfers on the outside of the spoke holes. When you lace heads out the spoke head fits in the countersink. That leaves the elbows unsupported. According to Jobst's book that causes breakage, and the right way to use a countersink is to put the elbow in it. With these hubs that means heads in.

I've switched to building mine that way. Some radial, some 1x.


Top
 Profile  
 
Posted: Mon Apr 22, 2013 8:44 pm 


Top
  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 11 posts ] 


Who is online

Users browsing this forum: LouisN, rmerka and 4 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  

   Similar Topics   Author   Replies   Views   Last post 
There are no new unread posts for this topic. Tandem Carbon wheelset, spoke count questions

in Everything wheels

shlammed

3

100

Fri Aug 22, 2014 7:59 pm

shlammed View the latest post

There are no new unread posts for this topic. What spoke and length do my wheel require?

in Road

eigner

3

157

Wed Jul 16, 2014 10:36 am

eigner View the latest post

There are no new unread posts for this topic. tri spoke vs disk/deep wheel

in Everything wheels

milehighcyclist

11

665

Mon Aug 11, 2014 7:40 pm

HillRPete View the latest post

There are no new unread posts for this topic. effect of spoke type on wheel stiffness

[ Go to page: 1, 2 ]

in Road

nmrt

23

1186

Mon Jun 02, 2014 10:07 pm

bm0p700f View the latest post

There are no new unread posts for this topic. SPOKE choice for light WHEELS

in Everything wheels

wally318

5

945

Fri Oct 04, 2013 4:31 am

eric View the latest post


It is currently Tue Sep 16, 2014 1:20 pm

All times are UTC + 1 hour




Advertising   –  FAQ   –  Contact   –  Convert   –  About

© Weight Weenies 2000-2013
hosted by starbike.com


How to get rid of these ads? Just register!


Powered by phpBB