A Cycling & bikes forum. CycleBanter.com

Go Back   Home » CycleBanter.com forum » rec.bicycles » Techniques
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Residual stress, fatigue and stress relief



 
 
Thread Tools Display Modes
  #61  
Old April 26th 08, 07:33 PM posted to rec.bicycles.tech
jim beam
external usenet poster
 
Posts: 5,758
Default Residual stress, fatigue and stress relief

daveornee wrote:
jim beam Wrote:
daveornee wrote:
Ron Ruff Wrote:
On Apr 24, 9:59*pm, jim beam wrote:
manufacturers actually state that spokes /shouldn't/ be bent.
Everybody I know who uses Sapim spokes bends them. Dave Ornee, what

do
you do?
I bend the heads in ones to a slightly smaller angle (depending on

the
hub, crossing pattern and rim ERD) with spokes laced and nipples

turned
5 full turns. Some hubs like Phil Wood have canted flanges so I

don't
bend spokes on them unless it looks like it will improve the spoke

line.
Yes, I saw what Sapim says on their web site about not bending, but

I
find that the improved spoke line is benenficial in the long run. I
have had one returned wheel from over 1,000 built with a broken

spoke...
and it broke at the end of the spoke shaft just at the elbow. I

tossed
the spoke and all 31 of the others in the wheel (no pictures as I

forgot
to take the time and wanted to get the wheel back to the rider) and
rebuilt it with all new spokes and new nipples.
Hub is Dura Ace 7700 rear (25th Annivesary) rim is Velocity Fusion.
I saw the spokes in Jim Beams pictures. That is interesting. Some

day
I will photograph spokes before & after... inbound and outbound +

spoke
holes prebuild and post build, including post stabilizing.

this is the hub those spokes came from:
http://www.flickr.com/photos/38636024@N00/104463818/

that hub hole deformation is *definitely* going to affect exit angle.
and thus "correcting" the spoke line /before/ tensioning [and
stabilizing], as most people do, is going to be premature.


If any of you have such pictures already I would like to see them

and
get some suggestions how to get the details photographed such that

you
can really discern what is going on.


Here are links to 6 pictures I took today of a Dura Ace HB-7700 32H
wheel I built today with Sapim Race 14/15 DB spokes. One side I used my
previous pattern of "correcting the spoke line" and the other side I
made no such correction.
Judge for yourself.


http://www.flickr.com/photos/17085834@N08/2443679334/


http://www.flickr.com/photos/17085834@N08/2443679236/


http://www.flickr.com/photos/17085834@N08/2442851273/


http://www.flickr.com/photos/17085834@N08/2443679416/


http://www.flickr.com/photos/17085834@N08/2442851411/


http://www.flickr.com/photos/17085834@N08/2442851349/


After this experiment I think the next build will be done without
correcting the spoke line.



aren't modern digicams fantastic???

one other thing i've noticed, not that it really makes much difference,
is that the spoke head on the "uncorrected" spoke always sits in the hub
hole just that little bit better.
Ads
  #62  
Old April 26th 08, 08:18 PM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 7,934
Default Residual stress, fatigue and stress relief

On Sun, 27 Apr 2008 04:22:58 +1000, daveornee
wrote:

Here are links to 6 pictures I took today of a Dura Ace HB-7700 32H
wheel I built today with Sapim Race 14/15 DB spokes. One side I used my
previous pattern of "correcting the spoke line" and the other side I
made no such correction.
Judge for yourself.

http://www.flickr.com/photos/17085834@N08/2443679334/

http://www.flickr.com/photos/17085834@N08/2443679236/

http://www.flickr.com/photos/17085834@N08/2442851273/

http://www.flickr.com/photos/17085834@N08/2443679416/

http://www.flickr.com/photos/17085834@N08/2442851411/

http://www.flickr.com/photos/17085834@N08/2442851349/

After this experiment I think the next build will be done without
correcting the spoke line.


Dear Dave,

Nice pictures--thanks!

Yikes!
http://www.flickr.com/photos/17085834@N08/2443679416/
http://www.flickr.com/photos/17085834@N08/2442851349/

Cheers,

Carl Fogel
  #64  
Old April 26th 08, 09:44 PM posted to rec.bicycles.tech
daveornee[_189_]
external usenet poster
 
Posts: 1
Default Residual stress, fatigue and stress relief


Wrote: [color=blue]
On Sun, 27 Apr 2008 04:22:58 +1000, daveornee
wrote:

SNIP
http://www.flickr.com/photos/17085834@N08/2443679416/
http://www.flickr.com/photos/17085834@N08/2442851349/

Cheers,

Carl Fogel

If you just built em and rode them without stabilizing them, they would
look quite similar after riding them a short while. The difference is
that you can put a controlled force amount in stabilizing them and get
the wheels trued, tensioned, tension balanced, centered and they will
stay that way for a long time.


--
daveornee

  #65  
Old April 26th 08, 09:44 PM posted to rec.bicycles.tech
daveornee[_190_]
external usenet poster
 
Posts: 1
Default Residual stress, fatigue and stress relief


Wrote: [color=blue]
On Sun, 27 Apr 2008 04:22:58 +1000, daveornee
wrote:

SNIP
http://www.flickr.com/photos/17085834@N08/2443679416/
http://www.flickr.com/photos/17085834@N08/2442851349/

Cheers,

Carl Fogel

If you just built em and rode them without stabilizing them, they would
look quite similar after riding them a short while. The difference is
that you can put a controlled force amount in stabilizing them and get
the wheels trued, tensioned, tension balanced, centered and they will
stay that way for a long time.


--
daveornee

  #66  
Old April 27th 08, 04:22 PM posted to rec.bicycles.tech
Ron Ruff
external usenet poster
 
Posts: 1,304
Default Residual stress, fatigue and stress relief

On Apr 25, 10:09*pm, jim beam wrote:
that hub hole deformation is *definitely* going to affect exit angle.
and thus "correcting" the spoke line /before/ tensioning [and
stabilizing], as most people do, is going to be premature.


Exactly when and how much can be debated I suppose, but... Every hub I
use supports the spoke in such a way as to make the heads-in spokes
"stick out" ie they aren't heading straight to the rim but rather bow
outward. Increasing tension (even overloading) will not eliminate this
completely... so the spoke will end up with an additional bending
load, if nothing else is done about it. This is not a good thing.
Similarly, most rims I use do not allow spokes on the NDS and front
spokes to enter without some bending load at the rim. Some large
flange hubs create a pretty acute angle even on the DS.

I prefer to "correct the spoke line" at the hub rather late in the
building process, but before overloading. I agree that high tension is
probably better for achieving the best "shape" at that point. At the
rim I bend the spokes fairly early, just because it is too difficult
to do well when the tension is high. It seems to me that it is better
for the rim if the nipple lies more closely to perpendicular against
the surface of the rim, to reduce the chance of eyelet deformation and
cracking.

  #67  
Old April 27th 08, 04:37 PM posted to rec.bicycles.tech
jim beam
external usenet poster
 
Posts: 5,758
Default Residual stress, fatigue and stress relief

Ron Ruff wrote:
On Apr 25, 10:09�pm, jim beam wrote:
that hub hole deformation is *definitely* going to affect exit angle.
and thus "correcting" the spoke line /before/ tensioning [and
stabilizing], as most people do, is going to be premature.


Exactly when and how much can be debated I suppose, but... Every hub I
use supports the spoke in such a way as to make the heads-in spokes
"stick out" ie they aren't heading straight to the rim but rather bow
outward.


only when the hub is new and the hub holes un-deformed. to bend the
spoke a head of this deformation is premature because hub hole
deformation changes the exit angle. and it's the angle to which spokes
are pre-formed!

Increasing tension (even overloading) will not eliminate this
completely... so the spoke will end up with an additional bending
load, if nothing else is done about it.


that's not correct. both dave ornee and i have posted pics of spokes
that are unbent, and when disassembled, they prove that bending was
unnecessary.


This is not a good thing.


no, it's a misunderstanding and non-observation of the facts. see above.


Similarly, most rims I use do not allow spokes on the NDS and front
spokes to enter without some bending load at the rim. Some large
flange hubs create a pretty acute angle even on the DS.

I prefer to "correct the spoke line" at the hub rather late in the
building process, but before overloading. I agree that high tension is
probably better for achieving the best "shape" at that point. At the
rim I bend the spokes fairly early, just because it is too difficult
to do well when the tension is high. It seems to me that it is better
for the rim if the nipple lies more closely to perpendicular against
the surface of the rim, to reduce the chance of eyelet deformation and
cracking.


you have to overload to ensure bedding in - if you want your wheels to
remain true at any rate. and if your spoke tension is high enough to
cause rim deformation, it's too high - use a tension meter.
  #68  
Old April 27th 08, 05:08 PM posted to rec.bicycles.tech
jim beam
external usenet poster
 
Posts: 5,758
Default Residual stress, fatigue and stress relief

jim beam wrote:
Ron Ruff wrote:
On Apr 25, 10:09�pm, jim beam wrote:
that hub hole deformation is *definitely* going to affect exit angle.
and thus "correcting" the spoke line /before/ tensioning [and
stabilizing], as most people do, is going to be premature.


Exactly when and how much can be debated I suppose, but... Every hub I
use supports the spoke in such a way as to make the heads-in spokes
"stick out" ie they aren't heading straight to the rim but rather bow
outward.


only when the hub is new and the hub holes un-deformed. to bend the
spoke a head


typo - "ahead"

of this deformation is premature because hub hole
deformation changes the exit angle. and it's the angle to which spokes
are pre-formed!

Increasing tension (even overloading) will not eliminate this
completely... so the spoke will end up with an additional bending
load, if nothing else is done about it.


that's not correct. both dave ornee and i have posted pics of spokes
that are unbent, and when disassembled, they prove that bending was
unnecessary.


This is not a good thing.


no, it's a misunderstanding and non-observation of the facts. see above.


Similarly, most rims I use do not allow spokes on the NDS and front
spokes to enter without some bending load at the rim. Some large
flange hubs create a pretty acute angle even on the DS.

I prefer to "correct the spoke line" at the hub rather late in the
building process, but before overloading. I agree that high tension is
probably better for achieving the best "shape" at that point. At the
rim I bend the spokes fairly early, just because it is too difficult
to do well when the tension is high. It seems to me that it is better
for the rim if the nipple lies more closely to perpendicular against
the surface of the rim, to reduce the chance of eyelet deformation and
cracking.


you have to overload to ensure bedding in - if you want your wheels to
remain true at any rate. and if your spoke tension is high enough to
cause rim deformation, it's too high - use a tension meter.

 




Thread Tools
Display Modes

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

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Your best solution to relieving residual stress! liverliver Techniques 2 December 28th 07 06:48 PM
yet another residual stress redux jim beam Techniques 0 March 17th 07 10:41 PM
Spoke stress relief test [email protected] Techniques 32 December 27th 06 07:21 PM
Stress-relief demonstration suggestions? [email protected] Techniques 73 January 8th 05 03:09 AM
RR: Stress relief Mike Kennedy Mountain Biking 3 October 5th 04 06:59 PM


All times are GMT +1. The time now is 07:23 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright ©2004-2024 CycleBanter.com.
The comments are property of their posters.