Re: Maintenance Manuals

carlfogel@xxxxxxxxxxx wrote:
On Sat, 29 Sep 2007 16:38:15 -0400, Peter Cole
<peter_cole@xxxxxxxxxxx> wrote:

Frank Drackman wrote:
"jim beam" <spamvortex@xxxxxxxxxxxxxxx> wrote in message news:mZSdnW2KsY96yWPbnZ2dnUVZ_gOdnZ2d@xxxxxxxxxxxxxxxx
Ryan Cousineau wrote:
In article <1191039479.922619.176200@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
BigJulie <julianshapiro@xxxxxxxxx> wrote:

sutherland's

http://www.amazon.com/Sutherlands-Handbook-bicycle-mechanics-Sutherland/dp/091
4578065/ref=pd_bbs_2/102-4791940-4852967?ie=UTF8&s=books&qid=1191039436&sr=8-2


On Sep 29, 12:05 am, Mark <mblackwell1...@xxxxxxxxx> wrote:
Well as I am increasingly intrigued by the mechanics of bikes. There
is a lot I just have never taken apart, put back together, and frankly
don't fully understand how things work. I wondered if there is a book
that is accepted as "the book to have on bike maintenance" that shows
pictures and step by step instructions much the way the Chiltons book
does for auto repair.

I'd also be interested in books on bike design. Now I would like to
keep the theory to a practical level. No I have no idea to turn this
into an engineering project. I am already married to an engineer and
the last thing one needs is two engineers in the same house. lol
At a much lower price, Zinn and the Art of Mountain Bike Maintenance (and the similar Road Bike Maintenance) are good Chilton-level books. I'd just get the one for your primary kind of ride, as much of the material overlaps, and the differences aren't liable to catch you out unless you're a roadie and you decide to start doing your own fork maintenance on your MTB.

Sheldonbrown.com seems like it has directions on virtually every mechanical repair known to cycling, so it's almost as good as having your own bike manual.

I make no submission on most bike design books, but regular contributor here Jobst Brandt literally wrote the book
/a/ book.

on bicycle wheels, called "The Bicycle Wheel," and it covers both the theory of wheels and the proper procedure for wheelbuilding.

procedure, yes. theory? some of it is badly awry. spoke tension "as high as the rim can bear" for example is based on a fundamental misunderstanding by the author and that is of the most practical [and costly] consequence to the novice builder - excess tension can cause a higher propensity for rim buckling and directly cause rim cracking. the book should should be amended to specify spoke tension "as determined by the rim manufacturer".
I guess that we all saw that coming...sad

And completely wrong, it's not what the book says at all.

Dear Peter,

Here's what the 3rd edition says:

FINDING THE RIGHT TENSION

The following method works well in determining proper spoke tension
for conventional road rims of up to 43 0 grams with 36 spokes. Tighten
all the spokes a quarter turn at a time, starting at the valve stem
hole. Once a distinct tone can be made by plucking, and spokes are not
easily squeezed together by grasping them in pairs, it is time to
check tension. After each round of tightening, test the tension by
stress relieving. If the wheel becomes untrue in two large waves
during stress relieving, the maximum, safe tension has been exceeded.
Approach this tension carefully to avoid major rim distortions. When
the wheel loses alignment from stress relieving, loosen all spokes a
half turn before retruing the wheel

Cheers,

Carl Fogel

Yes, I know, I have that edition.

It also describes, in a previous section "Final Tensioning", use of a tensiometer (with drawing), and comparison by tone to a known good wheel as methods of achieving proper tension.

In the context, the method described above is given as an alternative with the stated qualifications (<430g, 36 spokes), presumably for those without tensiometers.

He goes on to say that for heavy rims or road rims with less than 32 spokes that tensioning is usually at the limit when nipples can no longer be easily turned.

The overall impression I get is that Jobst is trying to give people a feel for how tight spokes should be. It seems obvious that, for rims where the manufacturer has specified a maximum spoke tension, those limits should be observed, and a tensiometer is required to do that.

From its online manual, Mavic indicates that conventional 3 cross wheels should have tensions in the 70-90kg range. They also set weight limits on their road wheels (2008) for 100kg, bike rider & gear. Both seem low. Perhaps wheel builders using Mavic product should read the fine print carefully and never build without a tensiometer.

It would be interesting to know what the actual tension would be if the quoted procedure was followed for the kind of rim described. As far as I know, no one has reported that.
.

Relevant Pages

  • Re: 700/25 or 700/28
    ... built wheel is. ... Mostly I'd have to tension and re-true ... acompany a wheel built with woven spokes which have not been bent ... crossing and its 'straightness' from crossing to the rim. ...
    (rec.bicycles.tech)
  • Better than spoke squeezing?
    ... Mavic used to recommend stress-relieving a wheel by laying it flat ... on either side of the rim. ... as the tension is increased "until the wheel is perfect and the spokes ...
    (rec.bicycles.tech)
  • Re: rim life.. questions...
    ... >> You seem to be arguing that the tension does not alter the strength ... >> subject here is the strength of the complete assembled wheel. ... A few spokes would be left in the latter wheel so ...
    (rec.bicycles.tech)
  • Re: Any other pros break spokes?
    ... the tension curves that pass through ... what the graph would look like for different wheel setups. ... always start with a side load that completely slackens the spokes on ... showing the relationship between spoke tension and rim displacement ...
    (rec.bicycles.tech)
  • Re: Maintenance Manuals
    ... tension increases strength. ... Have you ever seen a "broken" wheel? ... As the wheel deforms more, more spokes become effectively removed, and a longer span of rim is unsupported, just like a span of railroad track. ...
    (rec.bicycles.tech)