back wheel wobble and loose spokes.

nappadang

Über Member
Location
Gateshead
I noticed a wobble on my back wheel while riding home from work. Closer examination revealed that all my spokes are loose causing roughly 5- 6 mm of play (wobble)
I cleaned the bike yesterday and didn't notice anything. Come to think of it, everything seemed fine this morning.
Any suggestions regarding what has happened would be appreciated as would advice on fixing it. Worst case scenario, how much am I going to be out of pocket?
Thanks in advance.
 

arch684

Veteran
Get a spoke key and check out some video's on youtube how to true a wheel.If you don't try you will never know
 

zacklaws

Veteran
Location
Beverley
Other things to look for are to see if their are any issues with the wheel itself as to what made them come loose. For example over the past two years I have had major issues with Mavic wheels, mainly the back one, and the first sign of a problem is loose spokes and a wobble in the wheel, and its all because the rim has cracked around the spoke nipples or the spoke nipples have been pulling out of the rim or the plastic hub has cracked or a combination of them issues. I am now on my 5th replacement Kysyrium Equipe rear in nearly 3 years now, and each wheel religiously breaks at 2600 miles and 168 hour riding time apart for my last that lasted just over 6000.

If you look for cracks, they can be very hard to spot as they may only be hairline fractures and sometimes its easier to detect them by scratching your finger nail around the spoke nipple to see if it snags.

I also have a set of Mavic Axiums and they are notorious for spokes coming loose. My remedy on that set of wheels is to remove the spoke and put some threadlock in the nipple when they come loose, but it is not the correct solution as it makes it difficult in the future to adjust them to true your wheel if need be as I have found out. As I rarely use them now as they are unreliable for long rides, I am hoping that if I have to use them in a crisis, they may have corroded in by now out in my leaky shed over the past two years.
 
Location
Loch side.
Other things to look for are to see if their are any issues with the wheel itself as to what made them come loose. For example over the past two years I have had major issues with Mavic wheels, mainly the back one, and the first sign of a problem is loose spokes and a wobble in the wheel, and its all because the rim has cracked around the spoke nipples cut cut cut cut .
Resized crack no 1.jpg
Resized crack no 5.jpg
Resized Cracked Mavic Crossmax SLR.jpg
Resized Cracked Rim 2.jpg
Resized cracked rim 4.jpg
Resized Rim cracks (6).jpg
Resozed Cracked Rim3.jpg
 

zacklaws

Veteran
Location
Beverley
Its took me all day to reply to the pictures, having picked up my new wheel yesterday, it sent a shiver down my spine looking at them wondering if this new wheel will look like that shortly and hope I'm not caught out on a long ride when it does again. Maybe 5th time lucky.
 

S.Giles

Guest
Could the problems in the pictures above have been caused by excessive spoke tension, possibly combined with super-light rim construction?
 
Location
Loch side.
Could the problems in the pictures above have been caused by excessive spoke tension, possibly combined with super-light rim construction?
No. Aluminium has a fatigue limit that cannot be eradicated by a lower tension. Steel is the opposite. Although spoke tension is an overlay on top of fatigue, removing the overlay cannot eliminate it. Aluminium will fatigue and all of this is inevitable, given enough mileage. It can be minimized by heavier (thicker wall) rims but the weight weenies don't see eye to eye on that one.
 

S.Giles

Guest
No. Aluminium has a fatigue limit that cannot be eradicated by a lower tension. Steel is the opposite. Although spoke tension is an overlay on top of fatigue, removing the overlay cannot eliminate it. Aluminium will fatigue and all of this is inevitable, given enough mileage. It can be minimized by heavier (thicker wall) rims but the weight weenies don't see eye to eye on that one.
Your assertion seems to be that the risk of a nipple tearing through an aluminium wheel rim cannot be minimised by minimising (within practical limits) the tension in the spoke? That is counter-intuitive, to say the least!

I think you're agreeing that lightweight construction of the rim is at least partly to blame, though? I've been riding (comparatively cheap) bicycles with (thick?) aluminium rims for decades, and never experienced a problem of this sort. Maybe cheap, heavy bicycles are better in some respects than expensive, light ones? I think I'll continue to give rims made of Baco-Foil a miss, even at the expense of a few grams!
 
Location
Loch side.
Your assertion seems to be that the risk of a nipple tearing through an aluminium wheel rim cannot be minimised by minimising (within practical limits) the tension in the spoke? That is counter-intuitive, to say the least!
A spoke never tears through a rim. During wheelbuilding I can break a 2mm spoke in tension without the sightlest bit of damage to even the thinnest rim. Like I said, rims fail through the mechanism of metal fatigue. When you were at school you marveled at your ability to break steal when you took a thick coat hanger wire and broke it by bending it a few dozen time. That's not the same as tearing the wire apart. LIke I said, aluminium has a fatigue limit that cannot be eradicated by spoke tension. Steel on the other hand, has a limit which if you never reach it, will give you infinite fatigue life. We make use of this limit when for instance, designing car springs. They just never break. ON a bicycle wheel, a spoke that's been stress relieved, has an infinite fatigue life. The rim as we know and I've photographed, has a limited life.

The reason it is perhaps counter intuitive is that by stressing the rim a lot through initial tension, you do not increase the amplitude of the cyclical stresses. These remain the same size, albeit overlayed on top of the tension stress. That initial stress does decrease the fatigue life a little bit.

Finally, you can't have a spoke with zero tension. Then you don't have a tensioned wheel, but that is another discussion completely.



I think you're agreeing that lightweight construction of the rim is at least partly to blame, though? I've been riding (comparatively cheap) bicycles with (thick?) aluminium rims for decades, and never experienced a problem of this sort. Maybe cheap, heavy bicycles are better in some respects than expensive, light ones? I think I'll continue to give rims made of Baco-Foil a miss, even at the expense of a few grams!
It is fully to blame and something I've never disagreed with. The lighter the rim, the higher the amplitude of the cyclical stress will be and hence the quicker metal fatigue will set in. As important as thickness is shape. A rim with a flat spoke bed will fatigue quicker than a rim with a sharp V bed. The latter will flex less and thus fatigue less. Lightweight rims are a curse and the bane of my life.

Yes, a cheaper (thicker) rim is more durable than a more expensive, but lightweight one, all else (including alloying metals) being the same.
 

raleighnut

Legendary Member
Location
On 3 Wheels
A spoke never tears through a rim. During wheelbuilding I can break a 2mm spoke in tension without the sightlest bit of damage to even the thinnest rim. Like I said, rims fail through the mechanism of metal fatigue. When you were at school you marveled at your ability to break steal when you took a thick coat hanger wire and broke it by bending it a few dozen time. That's not the same as tearing the wire apart. LIke I said, aluminium has a fatigue limit that cannot be eradicated by spoke tension. Steel on the other hand, has a limit which if you never reach it, will give you infinite fatigue life. We make use of this limit when for instance, designing car springs. They just never break. ON a bicycle wheel, a spoke that's been stress relieved, has an infinite fatigue life. The rim as we know and I've photographed, has a limited life.

The reason it is perhaps counter intuitive is that by stressing the rim a lot through initial tension, you do not increase the amplitude of the cyclical stresses. These remain the same size, albeit overlayed on top of the tension stress. That initial stress does decrease the fatigue life a little bit.

Finally, you can't have a spoke with zero tension. Then you don't have a tensioned wheel, but that is another discussion completely.





It is fully to blame and something I've never disagreed with. The lighter the rim, the higher the amplitude of the cyclical stress will be and hence the quicker metal fatigue will set in. As important as thickness is shape. A rim with a flat spoke bed will fatigue quicker than a rim with a sharp V bed. The latter will flex less and thus fatigue less. Lightweight rims are a curse and the bane of my life.

Yes, a cheaper (thicker) rim is more durable than a more expensive, but lightweight one, all else (including alloying metals) being the same.
I've replaced many broken springs on cars (both coil and leaf springs) and every now and then I've seen broken sections of spring laying by the roadside.
 

S.Giles

Guest
A spoke never tears through a rim. During wheelbuilding I can break a 2mm spoke in tension without the sightlest bit of damage to even the thinnest rim. Like I said, rims fail through the mechanism of metal fatigue.
I think this has become a largely semantic argument. I would describe the nipples in several of the posted photos as having 'torn through the rim', be it by the mechanism of metal fatigue, or otherwise. The following photo shows buckling of the aluminium, in addition to fatigue cracks. It's hard to imagine that too much spoke tension played no part in the buckling (if not the fatigue damage). I would think that fatigue initiated the problem, and spoke tension did the rest. I could be mistaken though, so won't argue my case any further since this isn't a subject in which I have very much experience.

resized-cracked-rim-2-jpg.79409.jpg
 

zacklaws

Veteran
Location
Beverley
I've replaced many broken springs on cars (both coil and leaf springs) and every now and then I've seen broken sections of spring laying by the roadside.
Another sore point with me at the moment, broke a shock absorber before Xmas and had a new set fitted, a couple of weeks later and only about 100 miles on them, one of the new ones broke and now I'm waiting to get them replaced under warranty......and a month has passed and nothing and can only use my car for very slow short runs if needed as its very bouncy at the back.

And to p**! me off more, just had a press fit BB fitted, along with new cranks fitted as the old ones were ruined with the old bearings corroded on damaging it, anothe big bill, and to find out press fit BB's are useless in the wet and only last about 3500 miles if your lucky which is nothing and not that easy to service yourself.
 
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