Salsa Delgado 700c Rim: Cracks?

Just went to replace a broken spoke on the rear wheel and...
Sheesh!.... Beau coups cracks in the rim.

I've built most of my wheels myself, but have never seen anything
like this - or, for that matter, any rim cracks at all. This
wheel has also broken about a half-dozen spokes so far - and I
don't think I've broken more than two or three spokes across all
my other bikes in the past 10+ years.

But this one is on my rigid bike and I weigh 200+... curb
hopping, and all that.

But still, this wheel is not that old - maybe a year or two max,
and I have to wonder if maybe I did something wrong in the build.

The cracks are about evenly distributed left/right and not
concentrated in any area of the rim. 12 nipples affected plus
the sidewall crack visible he http://tinyurl.com/7cqapmg

I mainly run 38's on it. It's so wide bc I want the option of
running Big Apples.

IIRC, I was pretty attentive to tension - using a tensiometer.

Is there an error that typically results in this?

Rim recommendations for the heavy rider? Fatter, softer tires?
--
Pete Cresswell

On May 30, 2:51*pm, "(PeteCresswell)" wrote:
Just went to replace a broken spoke on the rear wheel and...
Sheesh!.... Beau coups cracks in the rim.

I've built most of my wheels myself, but have never seen anything
like this - or, for that matter, any rim cracks at all. * This
wheel has also broken about a half-dozen spokes so far - and I
don't think I've broken more than two or three spokes across all
my other bikes in the past 10+ years.

But this one is on my rigid bike and I weigh 200+... curb
hopping, and all that.

But still, this wheel is not that old - maybe a year or two max,
and I have to wonder if maybe I did something wrong in the build.

The cracks are about evenly distributed left/right and not
concentrated in any area of the rim. * 12 nipples affected plus
the sidewall crack visible hehttp://tinyurl.com/7cqapmg

I mainly run 38's on it. *It's so wide bc I want the option of
running Big Apples.

IIRC, I was pretty attentive to tension - using a tensiometer.

Is there an error that typically results in this?

Rim recommendations for the heavy rider? * Fatter, softer tires?
--
Pete Cresswell

Pete, the picture does not come up. If the cracks are around the
spoke holes, then you have too much tension -- or a defective rim.
What sort of spoke tension are you running?

-- Jay Beattie.

On 31/05/12 07:51, (PeteCresswell) wrote:
Just went to replace a broken spoke on the rear wheel and...
Sheesh!.... Beau coups cracks in the rim.

I've built most of my wheels myself, but have never seen anything
like this - or, for that matter, any rim cracks at all. This
wheel has also broken about a half-dozen spokes so far - and I
don't think I've broken more than two or three spokes across all
my other bikes in the past 10+ years.

But this one is on my rigid bike and I weigh 200+... curb
hopping, and all that.

But still, this wheel is not that old - maybe a year or two max,
and I have to wonder if maybe I did something wrong in the build.

The cracks are about evenly distributed left/right and not
concentrated in any area of the rim. 12 nipples affected plus
the sidewall crack visible he http://tinyurl.com/7cqapmg

I get "Sorry, that page was not found."

I mainly run 38's on it. It's so wide bc I want the option of
running Big Apples.

IIRC, I was pretty attentive to tension - using a tensiometer.

Is there an error that typically results in this?

Rim recommendations for the heavy rider? Fatter, softer tires?

My first hit when I googled your rims.

http://www.excelsports.com/main.asp?...jor=1&minor=25

The first two reviews were not good. Both had problems similar to you.

From a quick look, I don't like the shape at all. The flat spoke bed
is not desirable to support the spoke tension. I'd prefer a deeper rim
so that the rim has more strength to distribute load over more spokes,
and the rim wall is more in line with the spoke tension.

--
JS.

Per Jay Beattie:
Pete, the picture does not come up

Mea Culpa.

I keep forgetting that Picassa defaults to restricted view for
new albums.

You sb able to see it now.
--
Pete Cresswell

On May 30, 5:47*pm, "(PeteCresswell)" wrote:
Per Jay Beattie:

Pete, the picture does not come up

Mea Culpa.

I keep forgetting that Picassa defaults to restricted view for
new albums.

You sb able to see it now.
--
Pete Cresswell

Yup, too much tension for that rim -- and if you used 100kgf or
thereabouts, then that rim is a POS. James faults the rim for having a
flat spoke bed, but that design was common thirty years ago and worked
fine -- although the equivalent rim -- let's say a Superchampion Mod
58 weighed almost 100 grams more. So it may no longer be a fine design
in a light-ish rim on a 130mm hub with a huge imbalance in tension
from right to left.

http://velobase.com/ViewComponent.as...=107&AbsPos=14

The weight listed on that site is low. I think the nominal weight for
the Mod 58 was 565g. Your rim is 470g (?).

IMO, it's all about weight, spoke gauge and spoke goop. If a rim is
too light to stay true without spoke-hole cracking tensions, then you
have to go to a heavier rim -- or go with lower spoke tensions.
thinner spokes and thread goop. That Delgado is not in the stupid
light category, although it's pretty light for a 29er rim getting hard
use. You could probably re-build the same rim with lower tension and
some spoke goop and be fine, but you may also want to consider
something a little beefier. Finding a deep dish rim with the same ERD
that you can swap to, though, will be impossible. Prepare to buy new
spokes, too.

-- Jay Beattie.

On 31/05/12 11:25, Jay Beattie wrote:
On May 30, 5:47 pm, wrote:
Per Jay Beattie:

Pete, the picture does not come up

Mea Culpa.

I keep forgetting that Picassa defaults to restricted view for
new albums.

You sb able to see it now.
--
Pete Cresswell

Yup, too much tension for that rim -- and if you used 100kgf or
thereabouts, then that rim is a POS. James faults the rim for having a
flat spoke bed, but that design was common thirty years ago and worked
fine -- although the equivalent rim -- let's say a Superchampion Mod
58 weighed almost 100 grams more. So it may no longer be a fine design
in a light-ish rim on a 130mm hub with a huge imbalance in tension
from right to left.

And possibly fewer spokes. I don't think Pete mentioned number of spokes?

http://velobase.com/ViewComponent.as...=107&AbsPos=14

The weight listed on that site is low. I think the nominal weight for
the Mod 58 was 565g. Your rim is 470g (?).

IMO, it's all about weight, spoke gauge and spoke goop. If a rim is
too light to stay true without spoke-hole cracking tensions, then you
have to go to a heavier rim -- or go with lower spoke tensions.
thinner spokes and thread goop. That Delgado is not in the stupid
light category, although it's pretty light for a 29er rim getting hard
use. You could probably re-build the same rim with lower tension and
some spoke goop and be fine, but you may also want to consider
something a little beefier. Finding a deep dish rim with the same ERD
that you can swap to, though, will be impossible. Prepare to buy new
spokes, too.

I was impressed by the spoke prices at http://www.c-4shop.com/ Much
cheaper than any here I've found, provided I spent enough to get free
shipping, which wasn't difficult when I added a pair of rims.

--
JS.

On May 30, 10:51*pm, "(PeteCresswell)" wrote:
Just went to replace a broken spoke on the rear wheel and...
Sheesh!.... Beau coups cracks in the rim.

I've built most of my wheels myself, but have never seen anything
like this - or, for that matter, any rim cracks at all. * This
wheel has also broken about a half-dozen spokes so far - and I
don't think I've broken more than two or three spokes across all
my other bikes in the past 10+ years.

But this one is on my rigid bike and I weigh 200+... curb
hopping, and all that.

But still, this wheel is not that old - maybe a year or two max,
and I have to wonder if maybe I did something wrong in the build.

The cracks are about evenly distributed left/right and not
concentrated in any area of the rim. * 12 nipples affected plus
the sidewall crack visible hehttp://tinyurl.com/7cqapmg

I mainly run 38's on it. *It's so wide bc I want the option of
running Big Apples.

IIRC, I was pretty attentive to tension - using a tensiometer.

Is there an error that typically results in this?

Denial of linseed oil, thin spokes coupled with excess tension.



Rim recommendations for the heavy rider? * Fatter, softer tires?

Just build them right. A rim over 450g will do. Use 14swg spokes
(15swg would likely be ample but just to make sure), boiled linseed
oil on the threads and no more than sufficient spoke tension to enable
good wheel tracking.

Per Jay Beattie:
...spoke goop...

Lubricant?

Finding a deep dish rim with the same ERD that you can swap
to, though, will be impossible. Prepare to buy new spokes, too.

That's part of what was behind my grasping for some other reason
than the rim as the cause.

Gotta pull out my tensiometer, dope out the conversion table, and
measure the tension... and then find out what Salsa recommends
and compare them. My hope would be that I erred on the high
side.
--
Pete Cresswell

Per James:
And possibly fewer spokes. I don't think Pete mentioned number of spokes?

32
--
Pete Cresswell

On May 31, 2:25*am, Jay Beattie wrote:
On May 30, 5:47*pm, "(PeteCresswell)" wrote:

Per Jay Beattie:

Pete, the picture does not come up

Mea Culpa.

I keep forgetting that Picassa defaults to restricted view for
new albums.

You sb able to see it now.
--
Pete Cresswell

Yup, too much tension for that rim -- and if you used 100kgf or
thereabouts, then that rim is a POS. James faults the rim for having a
flat spoke bed, but that design was common thirty years ago and worked
fine -- although the equivalent rim -- let's say a Superchampion Mod
58 weighed almost 100 grams more. So it may no longer be a fine design
in a light-ish rim on a 130mm hub with a huge imbalance in tension
from right to left.

http://velobase.com/ViewComponent.as...-42D6-958F-FCD....

The weight listed on that site is low. *I think the nominal weight for
the Mod 58 was 565g. Your rim is 470g (?).

IMO, it's all about weight, spoke gauge and spoke goop. *If a rim is
too light to stay true without spoke-hole cracking tensions, then you

Your presumption that a bicycle wheel should perform as a banjo is
erroneous.

have to go to a heavier rim -- or go with lower spoke tensions.

That is normal tensions, no truss-rod required.

thinner spokes and thread goop.

Thicker spokes offer greater stability and the ability to poperly
utilise lower spoke tensions which therefore protect the rim.

*That Delgado is not in the stupid
light category, although it's pretty light for a 29er rim getting hard
use. *You could probably re-build the same rim with lower tension and
some spoke goop and be fine, but you may also want to consider
something a little beefier. Finding a deep dish rim with the same ERD
that you can swap to, though, will be impossible. Prepare to buy new
spokes, too.

-- Jay Beattie.