Straightness of Sapim CX-Ray Spokes
01-31-18, 11:43 PM
#1
Newbie
Thread Starter
Straightness of Sapim CX-Ray Spokes
Hi Folks,
Yesterday, I received some Sapim CX-Ray Spokes that I bought for a new wheel build. It is the first time I have bought these spokes and I am NOT impressed by the lack of Quality Control as you will see from the photos I have attached.
I scaled the images down to a width of 1800 pixels. So, if you set your Page Zoom to 100% (Ctrl+0 - Firefox, Pale Moon), you should be able to see the full image on most monitors.
As you can see, they are not very straight and some are much worse than others and on top of that you have the threaded end not always following the same arc as the flat section. See the 2nd and 8th spokes from the bottom in the first image.
I would have expected the spokes to be absolutely straight along the plane where the spokes are flat but as you can see they are bowed to varying degrees.
How could you be expected to build a wheel, with as close to uniform spoke tension as possible, with spokes like these?
Flexibility in the flat plane is significantly reduced in comparison to the opposing plane and in comparison to Round spokes. If instinct and logic serve me correctly, it would cause extra stress in the middle of the arc on the outer edge of the arc when the spoke is straightened under tension.
Has anyone else had a similar experience with these spokes?
Has anyone else had a similar experience with DT Aerolite spokes?
How was the situation resolved?
Thanks, MTB.
Yesterday, I received some Sapim CX-Ray Spokes that I bought for a new wheel build. It is the first time I have bought these spokes and I am NOT impressed by the lack of Quality Control as you will see from the photos I have attached.
I scaled the images down to a width of 1800 pixels. So, if you set your Page Zoom to 100% (Ctrl+0 - Firefox, Pale Moon), you should be able to see the full image on most monitors.
As you can see, they are not very straight and some are much worse than others and on top of that you have the threaded end not always following the same arc as the flat section. See the 2nd and 8th spokes from the bottom in the first image.
I would have expected the spokes to be absolutely straight along the plane where the spokes are flat but as you can see they are bowed to varying degrees.
How could you be expected to build a wheel, with as close to uniform spoke tension as possible, with spokes like these?
Flexibility in the flat plane is significantly reduced in comparison to the opposing plane and in comparison to Round spokes. If instinct and logic serve me correctly, it would cause extra stress in the middle of the arc on the outer edge of the arc when the spoke is straightened under tension.
Has anyone else had a similar experience with these spokes?
Has anyone else had a similar experience with DT Aerolite spokes?
How was the situation resolved?
Thanks, MTB.
01-31-18, 11:54 PM
#2
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 38,706
Bikes: too many bikes from 1967 10s (5x2)Frejus to a Sumitomo Ti/Chorus aluminum 10s (10x2), plus one non-susp mtn bike I use as my commuter
Mentioned: 140 Post(s)
Tagged: 1 Thread(s)
Quoted: 5779 Post(s)
Liked 2,576 Times
in
1,427 Posts
It's not rare for ovalized spokes to be a bit "squirmy". It happens during the step when the round profile is flattened to the aero shape.
In any case, it doesn't matter, and the tension will pull it straight when the wheel is built.
In any case, it doesn't matter, and the tension will pull it straight when the wheel is built.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.
02-01-18, 12:06 AM
#3
Senior Member
Join Date: May 2011
Location: Upstate NY
Posts: 3,783
Bikes: Bianchi San Mateo and a few others
Mentioned: 18 Post(s)
Tagged: 0 Thread(s)
Quoted: 634 Post(s)
Likes: 0
Liked 13 Times
in
9 Posts
There's no problem with the slight curvature in those spokes. The amount of tension needed to pull them straight is miniscule and won't make any difference at all.
02-01-18, 12:28 AM
#4
Disco Infiltrator
Join Date: May 2013
Location: Folsom CA
Posts: 13,446
Bikes: Stormchaser, Paramount, Tilt, Samba tandem
Mentioned: 72 Post(s)
Tagged: 0 Thread(s)
Quoted: 3126 Post(s)
Liked 2,105 Times
in
1,369 Posts
Go hang 250 lb from one of these and report back if it's still wavy.
__________________
Genesis 49:16-17
Genesis 49:16-17
02-01-18, 12:45 AM
#5
Senior Member
I strongly doubt that it actually matters. The center of the spoke is not the usual result of failure, and the amount that the spoke will have mechanical stress at the head (to seat against the flange) and at the threads (to match the spoke line) have to be orders of magnitude greater than straightening the middle, butted/bladed section of the spoke under elongation.
This does not make uniform tension any more difficult, but as with any wheel stress relieving is important in part to make sure that spokes do not settle in and assume a lower tension.
This does not make uniform tension any more difficult, but as with any wheel stress relieving is important in part to make sure that spokes do not settle in and assume a lower tension.
02-01-18, 01:25 AM
#6
Senior Member
Join Date: Apr 2011
Posts: 7,047
Mentioned: 41 Post(s)
Tagged: 0 Thread(s)
Quoted: 4390 Post(s)
Liked 1,555 Times
in
1,020 Posts
You do realize you are going to be bending every one of the heads-in spokes to build the wheel properly?
And if you don't know that, don't build the wheel until you do.
And if you don't know that, don't build the wheel until you do.
02-01-18, 06:23 AM
#7
Senior member
Join Date: Oct 2004
Location: Oakville Ontario
Posts: 8,117
Mentioned: 25 Post(s)
Tagged: 0 Thread(s)
Quoted: 943 Post(s)
Liked 658 Times
in
371 Posts
There's no issue here. As long as they are uniform length when fully straight. They will be straight when tensioned.
My all time favorite spoke to build with.
My all time favorite spoke to build with.
02-01-18, 06:43 AM
#8
Senior Member
Join Date: Jan 2005
Location: Baltimore, MD
Posts: 5,373
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 2482 Post(s)
Liked 2,952 Times
in
1,677 Posts
In the old days, touring cyclists sometimes stored spare spokes in their drop handlebars. The resulting bends in the stored spokes did not affect the utility of the spokes.
02-01-18, 10:00 AM
#9
Senior Member
Join Date: Feb 2014
Location: Pasadena, CA
Posts: 4,848
Bikes: Schwinn Varsity
Mentioned: 22 Post(s)
Tagged: 0 Thread(s)
Quoted: 1931 Post(s)
Liked 742 Times
in
422 Posts
Best spokes I've ever built wheels with. Maybe you bought counterfeits off ebay.
I'd be more worried about the use of VHS.... we don't do that anymore.
We have gone to DVD and even blu ray now.
I'd be more worried about the use of VHS.... we don't do that anymore.
We have gone to DVD and even blu ray now.
02-01-18, 10:26 AM
#10
working on my sandal tan
Join Date: Aug 2011
Location: CID
Posts: 22,629
Bikes: 1991 Bianchi Eros, 1964 Armstrong, 1988 Diamondback Ascent, 1988 Bianchi Premio, 1987 Bianchi Sport SX, 1980s Raleigh mixte (hers), All-City Space Horse (hers)
Mentioned: 98 Post(s)
Tagged: 0 Thread(s)
Quoted: 3871 Post(s)
Liked 2,568 Times
in
1,579 Posts
02-01-18, 12:30 PM
#12
Senior Member
Join Date: Sep 2004
Location: Chicago area
Posts: 2,551
Bikes: Airborne "Carpe Diem", Motobecane "Mirage", Trek 6000, Strida 2, Dahon "Helios XL", Dahon "Mu XL", Tern "Verge S11i"
Mentioned: 23 Post(s)
Tagged: 0 Thread(s)
Quoted: 980 Post(s)
Liked 582 Times
in
399 Posts
Sapim makes a great product. I've got a set waiting to be built into a wheel right now.
Steve
02-01-18, 03:28 PM
#13
Mechanic/Tourist
Don't write, ride. If you can't ride, wrench.
02-01-18, 05:08 PM
#14
Senior Member
Join Date: Jul 2009
Posts: 786
Mentioned: 14 Post(s)
Tagged: 0 Thread(s)
Quoted: 384 Post(s)
Likes: 0
Liked 6 Times
in
6 Posts
All this is why wheels should get pre-stressed/stress-relieved/whatever you want to call it, but it's at least partially to cold-set the spokes into their final laced and tensioned configuration. The elbows will set to the hub flange, there will probably be some misalignment of the nipples and the spoke line, and of course they interlace. In other words, even when finished they won't be perfectly straight. Which is fine. So none of the slight bent-ness out of the box is any practical problem at all on a well-built wheel, as many others have already said.
