Broken spokes query

just us said:

Steve has a Mavic X139 rim with Deore hubs and has done around 5000kms
mostly offroad. We were to go on a 3 day ride and sadly only 30kms into the
ride ( he had back panniers but only with a weight of approx 3kg each side)
he broke a couple of spokes and we had to limp home 🙁
Since then LBS has replaced the spokes and wheel looks quite straight again.
Question is - should he respoke with heavier duty spokes or is it time to
get a new rim? We dont want another failure - it upset our weekend plans
bigtime.
What would you do?

If it was me, I'd respoke the wheel. Not just the couple of broken
ones, do the whole lot.
I'd personally use DT Swiss 14 gauge spokes, although butted spokes may
be a better choice, I like to stick with straight gauge spokes.

just us said:

Steve has a Mavic X139 rim with Deore hubs and has done around
5000kms mostly offroad. We were to go on a 3 day ride and
sadly only 30kms into the ride ( he had back panniers but only
with a weight of approx 3kg each side) he broke a couple of
spokes and we had to limp home 🙁 Since then LBS has replaced
the spokes and wheel looks quite straight again. Question is -
should he respoke with heavier duty spokes or is it time to
get a new rim? We dont want another failure - it upset our
weekend plans bigtime. What would you do?

When touring decades ago (before stainless steel spokes), I
sometimes accumulated 5 broken rear-wheel spokes before I
bothered replacing any. I carried spare spokes on longer
trips.

A wheel built by a competent wheel-builder with 14 guage DT
spokes should break spokes only rarely, if ever. Bikes come
with machine-built wheels, and inevitable compromises are made.

For background information, see
http://sheldonbrown.com/wheelbuild.html#spokes

John

Hi Steve and Kathy,

You may remember my bicycle from the time I stayed at your home last July.

My spokes were 14 ga and not butted. I believe they are DT, but the
exact manufacturer does not really matter.

Between Borroloola and Cape Crawford my rear derailleur fell apart and
went into the wheel - breaking 3 spokes and bending some. I had the
bike shop in Katherine replace the broken and bent spokes, stress
relieve the spokes, and true up the wheel. Afterward it performed just
"like new" and did a great job on that hellish Nathan River Road. (As an
aside I liked that portion of the trip better than any other segment.) I
had not yet travelled 2000km on the wheels (PW 48 spoke hubs and double
walled Rhyno-Lite rims - heavy but TOUGH. They were excellent on the
Nathan River Road)

My situation is different from yours and Steve's as you are close to
LBS and travel lite so you can "limp home".

It is up to you whether to redo the wheel. Have you inspected the rim
thoroughly? Thickness of the sidewalls? How much braking is done? Are
the hubs cartridge type or free bearing type? The question is simple -
the correct answer for Steve is dependent on it's history and
maintenance schedule. The spokes should be stress-relieved while truing
and replacement. You could get more opinions from rec.bicycles.tech -
lots of folks watch that news group for tech advice.

Just my opinion. Snow here with -8C today. Too warm here for this time
of the year, but in 4 weeks I'll be moving to andworking in Dubai. The
Europe trip is on hold :-(

Ken, Canada

just us said:

Steve has a Mavic X139 rim with Deore hubs and has done around 5000kms
mostly offroad. We were to go on a 3 day ride and sadly only 30kms into the
ride ( he had back panniers but only with a weight of approx 3kg each side)
he broke a couple of spokes and we had to limp home 🙁
Since then LBS has replaced the spokes and wheel looks quite straight again.
Question is - should he respoke with heavier duty spokes or is it time to
get a new rim? We dont want another failure - it upset our weekend plans
bigtime.
What would you do?
Kathy.

Kathy, were you going to respoke it yourself? It's not too hard and if
you learn the skill, you'll be well placed for future misadventures.
There are good internet resources such as Sheldon Brown. One to look
for is an Excel spreadsheet called Spocalc - you input the hub and rim
and it calculates the spoke length you require, so you can order the
right ones. Also search the history on aus.bicycle and rec.bicycle.tech
(FAQ page). A few US shops including AEBike.com sell spokes and I think
phantom.com.au also does.

Donga

Donga said:

A few US shops including AEBike.com sell spokes and I think
phantom.com.au also does.

Indeed Phantom Cycles does. I use the DT "Competition"
double-butted 14/15 guage shown here:
http://www.phantomcycles.com.au/home.php?cat=180

The length measurement is from bend to end (but not including
the bend itself).

John