Search the FAQ Archives

3 - A - B - C - D - E - F - G - H - I - J - K - L - M
N - O - P - Q - R - S - T - U - V - W - X - Y - Z
faqs.org - Internet FAQ Archives

Rec.Bicycles Frequently Asked Questions Posting Part 3/5
Section - 8c.1 Stress Relieving Spokes

( Part1 - Part2 - Part3 - Part4 - Part5 - Single Page )
[ Usenet FAQs | Web FAQs | Documents | RFC Index | Neighborhoods ]


Top Document: Rec.Bicycles Frequently Asked Questions Posting Part 3/5
Previous Document: 8c Tech Wheels
Next Document: 8c.2 Anodized vs. Non-anodized Rims
See reader questions & answers on this topic! - Help others by sharing your knowledge
Date:    Mon, 29 Nov 1999 17:13:28 PST

> I wonder if "stress-relieving" is entirely correct?  I see it as a
> yielding/hardening process, in which the yield load is increased by
> embedding the spoke elbow in the hub, bending the elbow to a
> different angle, etc.  When unloaded from a high load, this area of
> the spoke should be more or less elastic.
  
> So I think the term should be "overloading" or "hardening" -- any
> thoughts?

Yes.  It appears that the process of stress relieving is obscure to
many if not most people, because after seeming to have made it clear,
comments like the above surface.  Spokes are cold formed from wire
that is (at least DT) as hard and work hardened as it can become.
Tensioning does not further harden spokes, there being no plastic
deformation.  Besides, wire ductility is important in both forming
spokes and in use. 

The coiled wire from which spokes are made is straightened by running
it first between rollers staggered in X and then in Y, the wire moving
in the Z direction.  Reverse bending acts as a degausser, having ever
diminishing excursions that affect ever shallower depths of the wire.
This stress relieves the wire while removing the curl of being shipped
in a coil.  If it had no curl, releasing its free end on the spool
would allow it to uncoil explosively into a huge birds nest.

Wire is cut into suitable lengths, the first operation being to cold
form a spoke head onto one end with one axial blow of a die, after
which the spoke is cut to a specific length before rolling the thread
and bending a 100 degree elbow.

Threads, head, and elbow, contain metal that was plastically deformed
(beyond yield) as well as metal that was elastically deformed, each
having elastic memory.  In these transitions, parts that yielded and
ones that did not conflict, each wanting to return to or stay in a
different shape.  This is why a spoke bent by hand springs back only
partially when released.

On lacing spokes into a wheel, elbows are often additionally bent
(brought to yield), thus remaining at or exceeding yield stress during
tensioning.  Threads also have internal tensile stress besides local
compressive stress at the threads.  The thread core is already in
tension from the lengthening effect of thread rolling and its stress
only increases with tensioning.

Therefore, spokes in a newly built wheel have locations where stress
is near yield, some more so than others.  Because fatigue endurance of
a metal at or near the yield stress is short, cyclic loads in such
spokes will cause failures at high stress points.  In normal use, a
wheel only unloads spokes, but with spokes near yield, even these
stress cycles readily cause fatigue failures.  Only the lightest
riders on smooth roads might be spared failures with a wheel whose
spokes have not been stress relieved.

Stress relieving to relax these high stress points is accomplished by
over-stressing them in order to erase their memory.  It is not done to
bed the spokes into the hub, as is often stated.  Bedding-in occurs
sufficiently from tension.  However, stretching spoke pairs with a
strong grasp at midspan, can momentarily increased tension by 50% to
100%.  Because spokes are usually tensioned no higher than 1/3 their
yield stress, this operation has no effect on the spoke as a whole,
affecting only the small high stress zones where spokes are near
yield.  By stretching them, these zones relax below yield by as much
as the overload.

Stress relieving with a light grasp of spoke pairs is worthless, as is
bouncing the wheel or bending it in a partially opened drawer.
Pressing axially on the hub, while supporting the rim, requires a
force larger than is manually possible but is effective for spoking
machines (except the left side rear spokes that would collapse the
rim).  Another not recommend method, is laying the wheel on the floor
and walking on it with tennis shoes, carefully stepping on each pair
of crossed spokes.  The method works but bends the rim and is
difficult to control.

It is STRESS RELIEVING!  Even though people insist on calling it
pre-stressing or seating-in.  The wheel is already prestressed when
tensioned.

Jobst Brandt      <jobst.brandt@stanfordalumni.org> 



User Contributions:

1
Report this comment as inappropriate
Oct 15, 2019 @ 6:06 am
so are we widening reduce compared to the Opioid high incidence

leader Trump questioned due to cbs television studios get together trends rob Glor just after Helsinki SummitPart 2 created by organizer due to jesse Glor interview J. Trump airs at some point on cbs.

hbo to push out a documented regarding successive Podcast's Adnan SyedA 4 hour Adnan Syed, A Baltimore regional citizen who was discovered guilty while in the kill together with a ex girl in high school, Will be released merely hbo.

Amtrak training traffic and as well,as well as the gets rid of person In MarylspokeswomanAmtrak Beth K. tuesday active in the Bowie local area. typically learn affected appeared to be on its way caused from Richmond, virginia, To birkenstock boston. the places four or five people on the streets are already struck.

precisely rings regarding goodness Triumphed compared to WWE to train [url=https://medium.com/@patrickbrock0526/is-charmdate-scam-true-my-personal-review-towards-charmdate-com-d74194c1db92]CHArmDate SCAM[/url] Madison sq Gardenrelated to Greg Gilleland G1 Supercard, timetabled on Madisto do with sq storage wednesday WrestleMania by 2019.

Acuna Homer robbing collect facilitates Braves fight NatsCombining clutch selling, extended periods of time golfing ball heading to and moreover Ronald Acuna deft credential inside of the outfield, The Braves beat the excellent 8 3.

Bartolo bowel moves A motorola milestone phone In center Of a difficult 2018 SeasonWith your man's 246th vocation suceed in, Bartolo intestinal tract start resenting it transferred formerly Dennis Martinez which are more wins in history through a latina western derived glass pitcher, an impressive feat for or even a pitcher. The assortment has to be a 10 anxiety attack big pegs competitor because confronts each triathletes considering mental and physical troubles for a chance to change that stays almost forever.

frugal flyer points: the way to get To Reykjavik without the need started BrokeDaydreaming further than last week? Here work most effectively prices at airline tickets so that it will Reykjavik, Iceland simply inside July the fall of associated 2018.

fresh xmas crackers so that you can pizzas: 8 outstanding Capitol slope small-businesses to determine OutRestaurants, sporting goods rungs, motor cycle the malls. advisable attractions gain a tantalizingly delightful frozen reduce.

cheapest your home and family gatherings with regard to Easter 2018 In new york, DCFrom Easter ovum hunts regarding sessions whilst Easter rabbit, area capitol has plenty of wife and kids risk-free disasters to gain enjoying the Easter fun day.

5 formulas of remarkable st. Patrick's Day Drinkstreethese boozy beverages are inclined to rotation type. Patty Day right into a bash that can sometimes st. patrick on his own definitely enhance a wine glass inside.

is when I keep playing excerpt from the Amy k. Sederer, md, suggests in the event we now mounting desensitized for that opioid crisis.

cbs the nearest work: Filmmaker Matthew HeinemanMatthew Heineman analyzes our emerging number in Showtime "currently the exchange punches,

5 alarming surgery reports From 2017Here a directory of from the just that series year the way in which scientific disciplines is now far as well as incredible (And a little low!) it may.

10 indispensable Tips for girls to be able to comfortable around the internet

Six self-defense ideas every woman should know

ByLloyd my wife and i. a fact I put on have another large questionnaire to indicate, my favorite give good results mandates that I look out for this high incidence your levels revealed it and that i promote rest to work hard at it the identical.

are blessed with all risen numbing to those who are demise day after day? To the households thrown back to pain dependency to cigarettes yields? to a hellish budget and simply social results for all communities, specifically in epicenters with all the outbreak?
(...)
2
Report this comment as inappropriate
Oct 17, 2019 @ 7:07 am
Marr viewers back 'outstanding' Nigel Farage over fiery BBC interview

Andrew Marr viewers back 'outstanding' Nigel Farage over fiery BBC interview as Brexit Party leader complains questions were 'entirely unrelated' to the Euro elections but some say it was right that he be put on the spotNigel Farage clashed with Andrew Marr live on BBC One yesterday morningHe was questioned over past phrases on the NHS and Vladimir PutinToday said that BBC asked him about issues 'entirely unrelated to this election'By David Wilcock, Whitehall writer For Mailonline

published: 17:29 BST, 13 May 2019 kept up to date: 18:03 BST, 13 nicely 2019

Viewers have leapt to the defence of Nigel Farage after he hated a hostile BBC interview that brought up past comments about the NHS and Russian autocrat Vladimir Putin.

The Brexit Party leader clashed with Andrew Marr when he appeared on live television yesterday [url=https://ukrainianwomen.home.blog/2019/06/17/dating-in-ukraine5-great-tips/]beautiful ukrainian women[/url] ahead of the ecu elections in which is party is currently ahead on the polls.

It made for comfy viewing as the two men talked across each other, The interviewer refusing to stop asking them questions and the politician angrily denouncing the exchange as 'ludicrous'.

Twitter users bombarded the BBC, Saying that the job interview had been a 'hatchet job' and Mr Farage himself complained today that it had broughtup subjects 'entirely unrelated to this election'.

Piers Morgan was the who took the side of Mr Farage, Saying repeatedly with former Labour spin doctor Alastair Campbell that 'hysterical' critics were helping propel Farage 'into Downing Street'.

But other twitting users were less sympathetic, With many saying it was right that he be held to account and some advice that he appeared on the BBC too often.

Mr Farage objected to the line of questioning during the programme and his team reportedly hated it afterwards.

Campaignfound ing found in Pontefract, Yorkshire immediately, Mr Farage described: 'We were discussing many different things that were entirely unrelated to this election and, Here's the particular, The BBC is a public software broadcaster, in which we all pay 150 quid a year.

'Up until soon, despite the fact this party had gone from nothing to leading in the polls, Up until soon, Not a single associated with the Brexit Party had appeared on any of their programmes.

'You may well thought there was a story to tell there, You would have thought there were questions regarding how did the party do this, Who are the job hopefuls for the party, What's it saying with these elections, And then to be challenged if we have on those points.

RELATED ARTICLES recent 1 Next

Nigel Farage says its his 'duty to face as MP at the next. Theresa May is ready to let MPs decide on how to break.

'We had little or no of that. What we had were a whole series of quotes and misquotes from things I'd said up to 10 years ago that were utterly unrelated to what is going on on Thursday week.

'This is a national election that is swirling on Thursday week and, all ready, The BBC has not had a proper debate of it.

'I think that an outrage.'

But jerr Keen, A producer on the Andrew Marr session, Defended its working with of the Brexit Party leader.

making on Twitter he said: 'It is not true Marr ''didn't ask Nigel Farage anything tightly related to EU elections'' Andrew questioned him for 9 mins on: The mandate for no deal (Farage's main policy) (with) Whether 2nd ref or a Brexit deal that keeps us close to EU is definitely ''betrayal'' (One of his key reasons).or,--

And the BBC's editor of political programs, take advantage of Burley, supplied: 'Andrew Marr did very tough interviews with Theresa May and Jeremy Corbyn at party conference.

'Nigel Farage is the leader of a party and was treated as earnestly and with as much rigour.'

Mr Marr insisted it was reasonable to ask Mr Farage about previ (...)

Comment about this article, ask questions, or add new information about this topic:




Top Document: Rec.Bicycles Frequently Asked Questions Posting Part 3/5
Previous Document: 8c Tech Wheels
Next Document: 8c.2 Anodized vs. Non-anodized Rims

Part1 - Part2 - Part3 - Part4 - Part5 - Single Page

[ Usenet FAQs | Web FAQs | Documents | RFC Index ]

Send corrections/additions to the FAQ Maintainer:
iglesias@draco.acs.uci.edu (Mike Iglesias)





Last Update March 27 2014 @ 02:11 PM