My tacoed rear wheel..



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K

kh6zv9

Guest
A few weeks ago I had a catastrophic failure on a rear rim after breaking one lousy spoke.

The rim was a 36 hole Araya 700c rim. Double wall and double eyelets. The wheel had less than 500
miles on it. I was using 14 straight gauge wheelsmith spokes. I weigh 250 pounds.

While coming down a steep curvy mountain grade ( I was using my brakes a lot ) , I popped a drive
side spoke (right side), and my wheel immediately tacoed and was trashed beyond repair.

I had to walk carrying the bike.

I can only suspect that I had built the wheel to tight.

The reason the spoke broke was from Chain Damage a few rides before when the chain jumped in between
the spokes and the cassette causing damage to all of my leading spokes.

Any thoughts on this are appreciated.

--------------------------------
Bob Masse' [email protected]
--------------------------------
 
D

Dion Dock

Guest
The little plastic "ring" that goes between the cassette and the spokes will prevent the chain from
going there again. The other alternative is to often check the rear derailleur limit screws to make
sure they don't shift into the rear wheel.

Where did your spoke break? Where the chain gouged it or at the end where its "elbow" went into the
hub? If it was from chain damage, you will need to replace the damaged spokes sooner. If it was at
the elbow, the wheel was not stress relieved.

It's unlikely the spokes were "too tight". The problem that leads to is they pull right
through the rim.

-Dion

<[email protected]> wrote in message news:[email protected]...
> A few weeks ago I had a catastrophic failure on a rear rim after breaking one lousy spoke.
>
> The rim was a 36 hole Araya 700c rim. Double wall and double eyelets. The wheel had less than 500
> miles on it. I was using 14 straight gauge wheelsmith spokes. I weigh 250 pounds.
>
> While coming down a steep curvy mountain grade ( I was using my brakes a lot ) , I popped a drive
> side spoke (right side), and my wheel immediately tacoed and was trashed beyond repair.
>
> I had to walk carrying the bike.
>
> I can only suspect that I had built the wheel to tight.
>
> The reason the spoke broke was from Chain Damage a few rides before when the chain jumped in
> between the spokes and the cassette causing damage to all of my leading spokes.
>
> Any thoughts on this are appreciated.
>
>
> --------------------------------
> Bob Masse' [email protected]
> --------------------------------
>
>
 
W

Woogoogle

Guest
[email protected] wrote in message news:<[email protected]>...
> A few weeks ago I had a catastrophic failure on a rear rim after breaking one lousy spoke.
>
> The rim was a 36 hole Araya 700c rim. Double wall and double eyelets. The wheel had less than 500
> miles on it. I was using 14 straight gauge wheelsmith spokes. I weigh 250 pounds.
>
At your weight and probable strength, you may need a wheel with more spokes like tandem wheels? I've
had a super light weight rear wheel buckle underneath me at 155#, but that was prolly cause it was
under tensioned or had some loose spokes after a couple of years of service.
 
B

Bluto

Guest
[email protected] wrote:

> A few weeks ago I had a catastrophic failure on a rear rim after breaking one lousy spoke.
>
> The rim was a 36 hole Araya 700c rim. Double wall and double eyelets. The wheel had less than 500
> miles on it. I was using 14 straight gauge wheelsmith spokes. I weigh 250 pounds.

You don't mention what particular rim is was, or what wheel size. You don't mention whether this was
on- or off-road. The rim may have been too light for the application, but there's not enough data
here to tell.

> While coming down a steep curvy mountain grade ( I was using my brakes a lot ) , I popped a drive
> side spoke (right side), and my wheel immediately tacoed and was trashed beyond repair.

The right side spokes are under twice the tension of those on the left. They are pulled so flat that
side loads apply large fluctuations in tension to these spokes. It's an inevitable side effect of
having 8, 9, or 10 speeds crammed into 130mm or 135mm rear spacing.

Were you staying centered over the bike, or hanging your body off to the inside or outside of the
turn? If you don't stay centered over the bike, you cause unnecessary side loads on the wheels.

> I can only suspect that I had built the wheel to tight.

That's not it. If the spoke broke at the elbow, then it was probably a faulty build, with
insufficient stress relieving. Oddly, breaking spokes is not a symptom of a too-tight build (usually
it's the opposite).

> The reason the spoke broke was from Chain Damage a few rides before when the chain jumped in
> between the spokes and the cassette causing damage to all of my leading spokes.

If the spoke broke at the point of chain damage, then it may well have broken from an overload.

I have to observe that it's none too surprising if a 250 pounder honking down a mountain road,
side-loading a ridiculously dished rear wheel with chain-damaged spokes, were to suffer a spoke
failure. If this spoke were to fail while being side loaded, it's none too surprising if the same
force that broke the spoke were to bend the wheel beyond repairability.

Not all these conditions may apply in your particular case.

Things you can do in the future to prevent recurrences include:

Use a spoke protector Build a dishless rear wheel with an offset rim and low dish hub Tension the
drive side spokes to 100-120kgf Properly stress relieve your spokes with a momentary overload Use a
heavier rim Use butted spokes, 13/14ga or 14/15ga right, 14/15ga or 15/16ga left Don't side load
your wheels unnecessarily

Good luck addressing your problem.

Chalo Colina
 
T

Tauras

Guest
Indeed more spokes the better, I bought my 8 year old a Haro BMX with 44 spokes per 20 inch wide
style rim. I can't believe the abuse I'm able to try to do to it a 200 lbs and 6'4", those pegs
are fun =)

Tauras http://www.kcbx.net/~tsulaiti/surfreport/

"WooGoogle" <[email protected]> wrote in message
news:[email protected]...
> [email protected] wrote in message
news:<[email protected]>...
> > A few weeks ago I had a catastrophic failure on a rear rim after
breaking
> > one lousy spoke.
> >
> > The rim was a 36 hole Araya 700c rim. Double wall and double eyelets. The wheel had less than
> > 500 miles on it. I was using 14 straight gauge wheelsmith spokes. I weigh 250 pounds.
> >
> At your weight and probable strength, you may need a wheel with more spokes like tandem wheels?
> I've had a super light weight rear wheel buckle underneath me at 155#, but that was prolly cause
> it was under tensioned or had some loose spokes after a couple of years of service.

-----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1
Newsgroup Service in the World! -----== Over 80,000 Newsgroups - 16 Different Servers! =-----
 
B

bball

Guest
I had a similar taco experience last fall also with a 36h Araya rim, 700c after re-tightening the
wheel excessively. (Early and enthusiastic attempts with a new truing stand.) Mine tacoed after a
brief downhill and turn onto the flats. No broken spoke but the tire came off the bead, tube emerged
and exploded. Fortunately I had a spoke wrench and spare tube, was on my way in short order. The
wheel re-trued and I learned my rudimentary lesson of not too tight.

Pride (and gung-ho with a spoke wrench) leadeth to a fall.

Beware the wheel singing soprano.

Bruce Ball
--------

On Fri, 18 Apr 2003 15:29:20 GMT, [email protected] wrote:

>A few weeks ago I had a catastrophic failure on a rear rim after breaking one lousy spoke.
>
>The rim was a 36 hole Araya 700c rim. Double wall and double eyelets. The wheel had less than 500
>miles on it. I was using 14 straight gauge wheelsmith spokes. I weigh 250 pounds.
>
>While coming down a steep curvy mountain grade ( I was using my brakes a lot ) , I popped a drive
>side spoke (right side), and my wheel immediately tacoed and was trashed beyond repair.
>
>I had to walk carrying the bike.
>
>I can only suspect that I had built the wheel to tight.
>
>The reason the spoke broke was from Chain Damage a few rides before when the chain jumped in
>between the spokes and the cassette causing damage to all of my leading spokes.
>
>Any thoughts on this are appreciated.
>
>
> --------------------------------
> Bob Masse' [email protected]
>--------------------------------
>
 
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