Broken Double-Butted Spokes?

I had a set of wheels build up, about 3 years ago. The shop builds plenty of wheels, and the
wheels were stress relieved. Mavic hubs, 36 thin double butted spokes, MA-2 in back, Torelli
Master in front.

Year one. During the first several months a rear spoke broke, but I forget which side. The shop
fixed it under warrantee. Several months later a second rear spoke broke, again I forget which side.
It was still under warrantee, but I paid the shop for the repair -- as the builder theorized that it
may have been because I dumped the bike once. Now I look more closely for manhole covers near
corners on wet roads. I retired the wheels for a year.

Year two. Didn't ride those wheels, as a mid 1980s Pinarello fell into my lap. Rode that instead. I
did bring the wheels into a renowned wheel builder at a different shop. He inspected them and
thought they were OK -- uniform tension and stress relieved. He didn't have much to offer about what
went wrong, as I didn't know which side the spokes broke on.

Year three. I've been riding those wheels again. Probably only 300 or so miles on them this year. A
spoke on the rear drive side broke, at the hub. I'm wondering if these are spokes that should have a
washer at each spoke head? I remember some talk in this ng several years ago about spokes being
built differently, and needing washers at the hub end. How can I find out if this is the case?
What's the best thing to do at this point?

Larry "New Tensiometer" Fieman.

 

Are these DT spokes? DT lengthened the bent section at the head of their spokes some while ago
(apparently to make automated spoking with machines easier) and this problem then surfaced with DT
spokes in some hubs. They then reduced the length of this section, but not back to the previous
value. Any spokes with the overly long head that were in the supply chain were left there...

But I don't think that this was three years ago, I think it happened more recently than that.

Nick

"Lawrence Fieman" <[email protected]> wrote in message news:[email protected]...
> I had a set of wheels build up, about 3 years ago. The shop builds plenty of wheels, and the
> wheels were stress relieved. Mavic hubs, 36 thin
double
> butted spokes, MA-2 in back, Torelli Master in front.
>
> Year one. During the first several months a rear spoke broke, but I
forget
> which side. The shop fixed it under warrantee. Several months later a second rear spoke broke,
> again I forget which side. It was still under warrantee, but I paid the shop for the repair -- as
> the builder theorized that it may have been because I dumped the bike once. Now I look more
> closely for manhole covers near corners on wet roads. I retired the wheels for a year.
>
> Year two. Didn't ride those wheels, as a mid 1980s Pinarello fell into my lap. Rode that instead.
> I did bring the wheels into a renowned wheel builder at a different shop. He inspected them and
> thought they were
OK --
> uniform tension and stress relieved. He didn't have much to offer about
what
> went wrong, as I didn't know which side the spokes broke on.
>
> Year three. I've been riding those wheels again. Probably only 300 or so miles on them this year.
> A spoke on the rear drive side broke, at the
hub.
> I'm wondering if these are spokes that should have a washer at each spoke head? I remember some
> talk in this ng several years ago about spokes
being
> built differently, and needing washers at the hub end. How can I find out if this is the case?
> What's the best thing to do at this point?
>
> Larry "New Tensiometer" Fieman.

 

"Lawrence Fieman" wrote:
> I had a set of wheels build up, about 3 years ago. The shop builds plenty of wheels, and the
> wheels were stress relieved. Mavic hubs, 36 thin
double
> butted spokes, MA-2 in back, Torelli Master in front.

> Year three. I've been riding those wheels again. Probably only 300 or so miles on them this year.
> A spoke on the rear drive side broke, at the
hub.
> I'm wondering if these are spokes that should have a washer at each spoke head? I remember some
> talk in this ng several years ago about spokes
being
> built differently, and needing washers at the hub end. How can I find out if this is the case?
> What's the best thing to do at this point?

The time frame you cite is consistent with the brief appearance of the long elbow DT spokes. Read
all about it at:

http://www.peterwhitecycles.com/DTspokes.htm

You can check which type you've got by measuring the elbow length as described in the article. I
unwittingling built a rear wheel with these spokes a couple of years ago and had similar problems.
The correct method for using these spokes with most hubs was to add washers. Otherwise, the outbound
spokes won't lay against the hub flange properly. I ended up re-building the wheel with newer
(shorter elbow) DT spokes and have had no more problems.

Unless you're a real heavyweight, using "thin" spokes (e.g., straight 15 ga, or db 15-16-15ga) in a
36 spoke wheel should be adequate.

Art Harris

 

> The time frame you cite is consistent with the brief appearance of the
long
> elbow DT spokes. Read all about it at:
>
> http://www.peterwhitecycles.com/DTspokes.htm
>
> Unless you're a real heavyweight, using "thin" spokes (e.g., straight 15
ga,
> or db 15-16-15ga) in a 36 spoke wheel should be adequate.

Thanks Art, Larry "170#" Fieman

 

How heavy are you? How rough are the roads? How hard do you "stomp" on the pedals? How many spokes
on the wheel?

All these can bust even the best built wheels, if they aren't appropriate for the job.

May you have the wind at your back. And a really low gear for the hills! Chris

Chris'Z Corner "The Website for the Common Bicyclist": http://www.geocities.com/czcorner