Wheel / spoke question

Tim Piester said:

Maybe its coincidence, maybe not, but for the second time this summer I had a rear spoke let go at
the same point in a ride. Both occurred at / just after the same RR tracks, going from road to
rail trail.

Quoted message said:

My question: Is it more likely that the spokes are old and prone to breaking, or am I banging too
hard over the rails of the tracks at an angle and causing them to break? I'm getting tired of
walking home the last 5 miles of an otherwise enjoyable 20 mile ride!

That depends on what sort of spokes they are. If they are nice shiny stainless steel spokes (when
you wipe them off) then they are probably high quality spokes because stainless steel is too
expensive to just make crummy spokes. In that case, someone built the wheels without doing the small
things that make wheels durable... improving the spoke line at the hub and nipple and most
importantly, stress relieving the spokes after final tensioning.

Spokes should last essentially forever considering the low stress they experience in use. However,
those low stresses, combined with residual high stresses left in the spokes from manufacture and
from bending them (yield stress) into place in the wheel, cause failures.

You can fix all this yourself and probably save money if you got the book that describes all
this. If you have a good bicycle shop, they ought to have it (if they sell books at all) or you
could order it:

avocet.comwheelbook.htmlOpen ↗

Jobst Brandt [email hidden] Palo Alto CA

[email hidden] wrote in message news:<[email hidden]>...

Quoted message said:

Tim Piester writes:

<snip>

Quoted message said:

Quoted message said:

My question: Is it more likely that the spokes are old and prone to breaking, or am I banging
too hard over the rails of the tracks at an angle and causing them to break? I'm getting tired
of walking home the last 5 miles of an otherwise enjoyable 20 mile ride!

Jobst replied <snip>

Quoted message said:

avocet.comwheelbook.htmlOpen ↗

Tom, in all probability your wheel was never properly tensioned and the spokes are failing from
simple fatigue as Jobst describes. The *best* solution is to have the wheel rebuilt with new spokes
by a competent wheelbuilder. Don't assume that the mechanic at your local bike shop is competent- I
built many wheels when I worked in a shop and I didn't learn what I was doing wrong until I read
"The Bicycle Wheel", long after I left the shop. I've built all my own wheels for many years and I
haven't broken a single spoke since I read "the book".

Jeff Wills

tim-<< My question: Is it more likely that the spokes are old and prone to breaking, or am I banging
too hard over the rails of the tracks at an angle and causing them to break? >><BR><BR>

As aluminum rims get worn, they get banged up, get 'deformed' and the spoke tension becomes uneven
and erratic. In some spot, the spoke will break, kinda like bending a coat hanger back and fiorth,
until it breaks. Breaking spokes is an indication you wheel is 'ill', and in need of a rebuild. New
rim, probably new spokes. Spokes don't wear out but rims do.

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
(303)440-3535 vecchios.comvecchios.comOpen ↗ "Ruote convenzionali costruite eccezionalmente bene"

Stock wheels, crappy spokes, poor machine-wheel build. Gonna happen a lot. Get the wheel relaced
with some DT spokes by a competent builder and your problems will end.