What, if anything, can be learnt about this spoke breakage?
#1
Senior Member
Thread Starter
Join Date: Jun 2022
Location: The Ring of Fire
Posts: 932
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 463 Post(s)
Liked 567 Times
in
356 Posts
What, if anything, can be learnt about this spoke breakage?
What, if anything, can be learnt about the cause of this spoke breakage from the image?
broken spoke on non-drive side
broken spoke on non-drive side
Last edited by Ron Damon; 02-26-24 at 11:16 PM.
#2
Really Old Senior Member
Bad luck.
Likes For Bill Kapaun:
#3
Senior Member
Nothing unusual. Spoke threads are rolled and not cut, so not as bad as cut, but thread minor diameter is still less than spoke body, so constitutes a stress concentration. Spoke also has the most bending stress right above the nipple (for rims that are not "aimed and drilled"). So pretty normal.
#4
Senior Member
Join Date: Jan 2005
Location: Baltimore, MD
Posts: 5,382
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 2490 Post(s)
Liked 2,958 Times
in
1,681 Posts
I broke several spokes, front and rear, in the wheels of a Specialized Langster that I'd bought new. I was surprised and annoyed that it began breaking spokes after only about six months of riding. (I bought that bike the first year of production. It had several other problems that Specialized corrected in later years.)
It, too, had black spokes. Some broke at the nipple, most at the elbow. I eventually rebuilt both wheels with new spokes.
My guess is that the black finish was meant to conceal the dull finish of low-grade steel.
It, too, had black spokes. Some broke at the nipple, most at the elbow. I eventually rebuilt both wheels with new spokes.
My guess is that the black finish was meant to conceal the dull finish of low-grade steel.
#5
Mother Nature's Son
Join Date: Mar 2016
Location: Sussex County, Delaware
Posts: 3,118
Bikes: 2014 Orbea Avant MD30, 2004 Airborne Zeppelin TI, 2003 Lemond Poprad, 2001 Lemond Tourmalet, 2014? Soma Smoothie
Mentioned: 15 Post(s)
Tagged: 0 Thread(s)
Quoted: 854 Post(s)
Liked 1,437 Times
in
819 Posts
I learnt they need to be replaced.
#6
Happy With My Bikes
Join Date: Sep 2020
Location: Oklahoma
Posts: 2,187
Bikes: Hi-Ten bike boomers, a Trek Domane and some projects
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 884 Post(s)
Liked 2,308 Times
in
1,118 Posts
I don't know if it is my eyes playing tricks, but it looks like there is an angle where the spoke exit the nipples on the adjacent spokes.
__________________
"It is the unknown around the corner that turns my wheels." -- Heinz Stücke
"It is the unknown around the corner that turns my wheels." -- Heinz Stücke
#7
Senior Member
Join Date: Dec 2010
Location: northern Deep South
Posts: 8,904
Bikes: Fuji Touring, Novara Randonee
Mentioned: 36 Post(s)
Tagged: 0 Thread(s)
Quoted: 2604 Post(s)
Liked 1,933 Times
in
1,213 Posts
On both sides, so it's probably not an optical illusion. I'd guess detensioning the wheel and putting a drop of oil on each nipple head might allow the nipple to rotate in the wheel when you re-tension. The wheel might be under-tensioned, but again that's an "internet expert" guess.
#8
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 38,726
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: 5793 Post(s)
Liked 2,592 Times
in
1,436 Posts
Some rims are drilled too close to the nipple diameter forcing it to align with the hole rather than the spoke.
If not properly stress relieved, the angle creates a local dead load.
Added to working loads this can bring the total stress beyond the fatigue limit.
If I see this kind of bend, I make doubly sure to stress relieve and retrue the wheel. If I made spec. decisions, the rim's maker would be told to address the problem or lose my business.
When dealing with rims, the phrase "wiggle room" needs to be taken literally.
Last edited by FBinNY; 02-27-24 at 10:35 AM.
#9
Senior Member
Join Date: Oct 2014
Location: Portland, OR
Posts: 12,909
Bikes: (2) ti TiCycles, 2007 w/ triple and 2011 fixed, 1979 Peter Mooney, ~1983 Trek 420 now fixed and ~1973 Raleigh Carlton Competition gravel grinder
Mentioned: 129 Post(s)
Tagged: 0 Thread(s)
Quoted: 4806 Post(s)
Liked 3,932 Times
in
2,557 Posts
On both sides, so it's probably not an optical illusion. I'd guess detensioning the wheel and putting a drop of oil on each nipple head might allow the nipple to rotate in the wheel when you re-tension. The wheel might be under-tensioned, but again that's an "internet expert" guess.
This may be the issue. Ideally spoke holes in rims are such that the nipple can float and properly align with the spoke.
Some rims are drilled too close to the nipple diameter forcing it to align with the hole rather than the spoke.
If not properly stress relieved, the angle creates a local dead load.
Added to working loads this can bring the total stress beyond the fatigue limit.
If I see this kind of bend, I make doubly sure to stress relieve and retrue the wheel. If I made spec. decisions, the rim's maker would be told to address the problem or lose my business.
When dealing with rims, the phrase "wiggle room" needs to be taken literally.
Some rims are drilled too close to the nipple diameter forcing it to align with the hole rather than the spoke.
If not properly stress relieved, the angle creates a local dead load.
Added to working loads this can bring the total stress beyond the fatigue limit.
If I see this kind of bend, I make doubly sure to stress relieve and retrue the wheel. If I made spec. decisions, the rim's maker would be told to address the problem or lose my business.
When dealing with rims, the phrase "wiggle room" needs to be taken literally.
I have broken spokes from bends there. Not a lot. I haven't focused on them when I build and it appears it shows.
#10
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 38,726
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: 5793 Post(s)
Liked 2,592 Times
in
1,436 Posts
Since this is an OEM wheel, it's a manufacturing or spec. defect, and IMO the manufacturer's responsibility to make it right.
To be clear, it's the OEM's job to make sure hub, rim, spokes, and number of crosses all are compatible. As I said earlier, I would not have accepted these rims, but it would probably have been OK if the finished wheel were properly stress relieved.
__________________
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.
Likes For FBinNY:
#11
Senior Member
Join Date: May 2010
Location: Bastrop Texas
Posts: 4,486
Bikes: Univega, Peu P6, Peu PR-10, Ted Williams, Peu UO-8, Peu UO-18 Mixte, Peu Dolomites
Mentioned: 13 Post(s)
Tagged: 0 Thread(s)
Quoted: 969 Post(s)
Liked 1,632 Times
in
1,048 Posts
Your Turn...
__________________
No matter where you're at... There you are... Δf:=f(1/2)-f(-1/2)
No matter where you're at... There you are... Δf:=f(1/2)-f(-1/2)
#12
Senior Member
broken spoke on non-drive side
As you're riding, the section of the rim at the contact patch gets flexed upwards a little relative to the hub. This momentarily shortens the spokes that are "passing through" the contact patch, causing them to drop in tension. If their tension was low in the first place (which is often the case for rear NDS spokes), they might go slack enough to wiggle and flex, which can fatigue the spoke where it contacts either the nipple or the hub.
Immediate fix is to replace the spoke. But when that happens, the wheel should be checked for appropriate spoke tension, and adequate spoke-to-spoke tension consistency. The failure may have been a fluke, but if it wasn't, you'll want to address the problem sooner rather than later.
Likes For HTupolev:
#13
Senior Member
Join Date: Oct 2014
Location: Portland, OR
Posts: 12,909
Bikes: (2) ti TiCycles, 2007 w/ triple and 2011 fixed, 1979 Peter Mooney, ~1983 Trek 420 now fixed and ~1973 Raleigh Carlton Competition gravel grinder
Mentioned: 129 Post(s)
Tagged: 0 Thread(s)
Quoted: 4806 Post(s)
Liked 3,932 Times
in
2,557 Posts
No matter what, it boils down to wiggle room.
Since this is an OEM wheel, it's a manufacturing or spec. defect, and IMO the manufacturer's responsibility to make it right.
To be clear, it's the OEM's job to make sure hub, rim, spokes, and number of crosses all are compatible. As I said earlier, I would not have accepted these rims, but it would probably have been OK if the finished wheel were properly stress relieved.
Since this is an OEM wheel, it's a manufacturing or spec. defect, and IMO the manufacturer's responsibility to make it right.
To be clear, it's the OEM's job to make sure hub, rim, spokes, and number of crosses all are compatible. As I said earlier, I would not have accepted these rims, but it would probably have been OK if the finished wheel were properly stress relieved.
Light to very light spokes and as many crosses as I can do because I love the ride.
So rims that aren't fussy as to spoke orientation, yeah! But I haven't broken enough spokes at the rim to raise it to awareness when buying. Thanks, FB, now I'll look harder. (And see if maybe spoke holes want to be tweaked on rims I really want for other reasons if these don't allow proper alignment. The Velocity Aeros seemed to be poorish in that respect. My two city bikes are my only clincher bikes now and I am guessing those wheels are going to go to a natural death. Not spoke shedders despite being Aero'd and on their second or so rim. Winter PNW lava grit brake wear.)
#14
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 38,726
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: 5793 Post(s)
Liked 2,592 Times
in
1,436 Posts
Spokes rarely break at the first thread stress riser.
Spokes bent at the nipple are fairly common, and yet this isn't a common cause of breakage. In any case there's a far worse bend at the other end.
But, a bend at the stress riser, that wasn't stress relieved, possibly compounded by other factors is simply too much.
__________________
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.
#15
Senior Member
Join Date: Feb 2012
Location: Rochester, NY
Posts: 18,098
Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4211 Post(s)
Liked 3,881 Times
in
2,316 Posts
Do I see a tad of corrosion at the spoke's broken end? Are the nipples Al? Andy
__________________
AndrewRStewart
AndrewRStewart
#16
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 38,726
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: 5793 Post(s)
Liked 2,592 Times
in
1,436 Posts
Hopefully the OP would have mentioned that.
OTOH based on cosmetics alone, I lean to downplaying corrosion worries.
__________________
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.
#17
Senior Member
More information about the wheel/build would be helpful.
Position of the broken spoke (DS, NDS, Disk brake side)?
# of spokes, cross pattern?
Unusual hub, flange diameter?
Butted spokes?
How deep within the nipple the first thread was (assuming that the break was there)
Bike type & use.
Position of the broken spoke (DS, NDS, Disk brake side)?
# of spokes, cross pattern?
Unusual hub, flange diameter?
Butted spokes?
How deep within the nipple the first thread was (assuming that the break was there)
Bike type & use.
#18
Senior Member
Thread Starter
Join Date: Jun 2022
Location: The Ring of Fire
Posts: 932
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 463 Post(s)
Liked 567 Times
in
356 Posts
- The wheel is not OEM, but rather hand built.
- It is 20" (ETRTO406), 24-spokes laced two-cross.
- It has broken spokes twice since 2018, this time being the second time.
- The spoke broke while riding.
Last edited by Ron Damon; 02-28-24 at 04:32 PM.
#19
Mad bike riding scientist
Join Date: Nov 2004
Location: Denver, CO
Posts: 27,369
Bikes: Some silver ones, a red one, a black and orange one, and a few titanium ones
Mentioned: 152 Post(s)
Tagged: 1 Thread(s)
Quoted: 6222 Post(s)
Liked 4,222 Times
in
2,368 Posts
The spoke may be too short or, more properly, have insufficient threads engaged with the nipple. In some Specialized OEM wheels of a certain age this is a common failure. The spokes don’t go through the nipple to the nipple head slot by several spoke threads in almost all of the ones that fail this way. The wheel can be properly tensioned and a nipple driver will still engage the nipple slot…can’t turn it but can still be put in there.
__________________
Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
Stuart Black
Plan Epsilon Around Lake Michigan in the era of Covid
Old School…When It Wasn’t Ancient bikepacking
Gold Fever Three days of dirt in Colorado
Pokin' around the Poconos A cold ride around Lake Erie
Dinosaurs in Colorado A mountain bike guide to the Purgatory Canyon dinosaur trackway
Solo Without Pie. The search for pie in the Midwest.
Picking the Scablands. Washington and Oregon, 2005. Pie and spiders on the Columbia River!
#20
Senior Member
Thread Starter
Join Date: Jun 2022
Location: The Ring of Fire
Posts: 932
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 463 Post(s)
Liked 567 Times
in
356 Posts
Fwiw
Broken spoke today at 12 o'clock. Replaced previous broken spoke, still intact today, at 6 o'clock.
Last edited by Ron Damon; 02-27-24 at 05:10 PM.
#21
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 38,726
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: 5793 Post(s)
Liked 2,592 Times
in
1,436 Posts
Doubly so if both spokes broke the same way.
BTW some of the nipples nicely align with the spokes and some don't. Is it possible that the rim is drilled forward and back (rare but not unheard of), and not laced to match? Otherwise it's hard to explain some, but not all unaligned nipples.
‐------------
Side note, having nothing to do with the issue.
I note that the wheel isn't mirrored (all trailing spokes either elbow in or out). Most hand builders mirror for a number of reasons. Machine built wheels are often built unmirrored because it's faster for a production worker. So, while this wouldn't cause failure at nipples, it argues against the wheel being hand built by a skilled builder.
Last edited by FBinNY; 02-27-24 at 05:03 PM.
#22
Senior Member
Thread Starter
Join Date: Jun 2022
Location: The Ring of Fire
Posts: 932
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 463 Post(s)
Liked 567 Times
in
356 Posts
The thick plottens...
I just noticed that the first broken spoke a couple of years back was the antipode of this second broken spoke today. That is, on this 24-spoke wheel, the first spoke broke at 12 spokes plus/minus this second broken spoke or exactly on the opposite side or 180 degrees apart, both times on the non-drive side. What does this tell us, if anything?
Last edited by Ron Damon; 02-27-24 at 05:12 PM.
#23
Senior Member
Join Date: Apr 2009
Location: New Rochelle, NY
Posts: 38,726
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: 5793 Post(s)
Liked 2,592 Times
in
1,436 Posts
I hate coincidences, but can't find a logical connection.
In any case, your main concern should be where to go from here.
Two spokes in two years isn't something I'd get worked up over.
Based on the long interval, I'd simply replace the spoke and true the wheel. With any luck the next break will be a year or more away.
If that next break happened sooner, I'd note the shrinking interval, and either rebuild or say last chance.
In any case, your main concern should be where to go from here.
Two spokes in two years isn't something I'd get worked up over.
Based on the long interval, I'd simply replace the spoke and true the wheel. With any luck the next break will be a year or more away.
If that next break happened sooner, I'd note the shrinking interval, and either rebuild or say last chance.
Last edited by FBinNY; 02-27-24 at 05:36 PM.
#24
Senior Member
Spokes angled at nipples: Very common on smaller wheel bikes, because with hubs being the same hole ring diameter as bigger wheels, you're gonna have more leading or trailing angle at the rim (for crossed spokes), and I don't think most rim makers take this into account, they just drill the holes pure radial, and there isn't enough nipple hole clearance for the nipple to swivel enough to be in alignment with the spoke. Every spoke on my 406 2X wheels are like that. Note: They are cheap Dahon single-wall rims, so the material is thick at the nipple hole, even thicker if that is actually a thin double-wall as some have speculated, I have not yet had apart since then to look closely.
I have not stress-relieved my wheel spokes. Only saw bit decades ago about doing that with feet, didn't seem precise to me. In recent days I read how to properly do this on sheldonbrown, gripping adjacent parallel spokes.
I have not stress-relieved my wheel spokes. Only saw bit decades ago about doing that with feet, didn't seem precise to me. In recent days I read how to properly do this on sheldonbrown, gripping adjacent parallel spokes.
Likes For Duragrouch:
#25
Senior Member
I just noticed that the first broken spoke a couple of years back was the antipode of this second broken spoke today. That is, on this 24-spoke wheel, the first spoke broke at 12 spokes plus/minus this second broken spoke or exactly on the opposite side or 180 degrees apart, both times on the non-drive side. What does this tell us, if anything?