Cracks and spoke tension

[[email protected]]

I just noticed cracks around ALL right hand eylets on my Mavic Reflex
tubular rim (32 hole, grey non-anodised). The cracks look similar to
these: http://web.onetel.net.uk/~davidwgreen/rimpics/4.JPG but some of
them are from side to side and at least one was all the way to the
"corner" where the side begins.

The rim is just a couple of years old and hasn't been ridden more than
5000 km. I build it myself using old spokes (DT 2/1.8 mm) and rather
high tension (the old rim had ~1300 N, this is probably about the
same, not yet on the "taco" limit) for right hand side. I weigh 82 kg
and ride on quite smooth roads.

The old rim was an anodised GP4, which I rode about 20 000 km until
one eylet was pulled through the rim. I hoped, that this new rim would
be better....

Am I just unlucky, is this a poor rim type or is the tension I use too
much? With lower tension I have had lot of problems with self
loosening left side spokes, which required wrenching every 100-200 km.
This wheel has stayed true.

If this rim fails, which low profile low cost tubular rim would you
recommend?

Joakim

 

[Chalo]

[email protected] wrote:
>
> I just noticed cracks around ALL right hand eylets on my Mavic Reflex
> tubular rim (32 hole, grey non-anodised). The cracks look similar to
> these:http://web.onetel.net.uk/~davidwgreen/rimpics/4.JPGbut some of
> them are from side to side and at least one was all the way to the
> "corner" where the side begins.

Mavic rims made since about 1990 are well known for having problems
with cracking at the spoke holes and at the sidewall root.

> Am I just unlucky, is this a poor rim type or is the tension I use too
> much? With lower tension I have had lot of problems with self
> loosening left side spokes, which required wrenching every 100-200 km.
> This wheel has stayed true.

My guess is that the tension you used was too much _because_ it's a
poor rim.

I have no recommendation for a good tubie rim because I don't use
them. If you need to use high spoke tension, be aware that aero
section rims are better at withstanding high spoke tension, generally
speaking.

Chalo

 

[Ben C]

On 2007-09-14, [email protected] <[email protected]> wrote:
> I just noticed cracks around ALL right hand eylets on my Mavic Reflex
> tubular rim (32 hole, grey non-anodised). The cracks look similar to
> these: http://web.onetel.net.uk/~davidwgreen/rimpics/4.JPG but some of
> them are from side to side and at least one was all the way to the
> "corner" where the side begins.
>
> The rim is just a couple of years old and hasn't been ridden more than
> 5000 km. I build it myself using old spokes (DT 2/1.8 mm) and rather
> high tension (the old rim had ~1300 N, this is probably about the
> same, not yet on the "taco" limit) for right hand side. I weigh 82 kg
> and ride on quite smooth roads.
>
> The old rim was an anodised GP4, which I rode about 20 000 km until
> one eylet was pulled through the rim. I hoped, that this new rim would
> be better....
>
> Am I just unlucky, is this a poor rim type or is the tension I use too
> much? With lower tension I have had lot of problems with self
> loosening left side spokes, which required wrenching every 100-200 km.
> This wheel has stayed true.

High tension is thought to be what causes those cracks.

You could try less tension and linseed or threadlock. This is not a
solution for the purists since in principle spokes shouldn't ever go
slack enough to unscrew. All the same it might work, and the only other
option is to find a better rim, which seems to me a bit of a lottery.

I'd probably try a different rim anyway, use linseed (which works as a
fairly mild threadlock), and a bit less tension.

 

[[email protected]]

On Sep 14, 3:35 am, [email protected] wrote:
> I just noticed cracks around ALL right hand eylets on my Mavic Reflex
> tubular rim (32 hole, grey non-anodised). The cracks look similar to
> these:http://web.onetel.net.uk/~davidwgreen/rimpics/4.JPGbut some of
> them are from side to side and at least one was all the way to the
> "corner" where the side begins.
>
> The rim is just a couple of years old and hasn't been ridden more than
> 5000 km. I build it myself using old spokes (DT 2/1.8 mm) and rather
> high tension (the old rim had ~1300 N, this is probably about the
> same, not yet on the "taco" limit) for right hand side. I weigh 82 kg
> and ride on quite smooth roads.
>
> The old rim was an anodised GP4, which I rode about 20 000 km until
> one eylet was pulled through the rim. I hoped, that this new rim would
> be better....
>
> Am I just unlucky, is this a poor rim type or is the tension I use too
> much? With lower tension I have had lot of problems with self
> loosening left side spokes, which required wrenching every 100-200 km.
> This wheel has stayed true.
>
> If this rim fails, which low profile low cost tubular rim would you
> recommend?
>
> Joakim

The Mavic Classics Pro wheel set of several years ago used, I presume,
their 32 hole Reflex tubular rims. The below linked specification
sheet indicates spoke tension of just 92-112 Kgf (10N = 1Kgf ).

http://www.tech-mavic.com/tech-mavi...E/Roues/ClassicsProCD/ClasProCDSpareParts.pdf

--

Spike

 

[Peter Cole]

Chalo wrote:
> [email protected] wrote:
>> I just noticed cracks around ALL right hand eylets on my Mavic Reflex
>> tubular rim (32 hole, grey non-anodised). The cracks look similar to
>> these:http://web.onetel.net.uk/~davidwgreen/rimpics/4.JPGbut some of
>> them are from side to side and at least one was all the way to the
>> "corner" where the side begins.
>
> Mavic rims made since about 1990 are well known for having problems
> with cracking at the spoke holes and at the sidewall root.
>
>> Am I just unlucky, is this a poor rim type or is the tension I use too
>> much? With lower tension I have had lot of problems with self
>> loosening left side spokes, which required wrenching every 100-200 km.
>> This wheel has stayed true.
>
> My guess is that the tension you used was too much _because_ it's a
> poor rim.
>
> I have no recommendation for a good tubie rim because I don't use
> them. If you need to use high spoke tension, be aware that aero
> section rims are better at withstanding high spoke tension, generally
> speaking.

I had the exact same problem with the clincher version of that rim. I
agree with Chalo, that it was a poor rim that wouldn't take the tension
required to keep the spokes from unscrewing. I went to Open Pros after 2
Reflex failures and didn't have the same problems.

 

[Qui si parla Campagnolo-www.vecchios.com]

On Sep 14, 2:35 am, [email protected] wrote:
> I just noticed cracks around ALL right hand eylets on my Mavic Reflex
> tubular rim (32 hole, grey non-anodised). The cracks look similar to
> these:http://web.onetel.net.uk/~davidwgreen/rimpics/4.JPGbut some of
> them are from side to side and at least one was all the way to the
> "corner" where the side begins.
>
> The rim is just a couple of years old and hasn't been ridden more than
> 5000 km. I build it myself using old spokes (DT 2/1.8 mm) and rather
> high tension (the old rim had ~1300 N, this is probably about the
> same, not yet on the "taco" limit) for right hand side. I weigh 82 kg
> and ride on quite smooth roads.
>
> The old rim was an anodised GP4, which I rode about 20 000 km until
> one eylet was pulled through the rim. I hoped, that this new rim would
> be better....
>
> Am I just unlucky, is this a poor rim type or is the tension I use too
> much?

Number 2 is my guess. mavic eyeleted rims do not like lots of
tension. 100 kgf, 105 or so max.

With lower tension I have had lot of problems with self
> loosening left side spokes, which required wrenching every 100-200 km.
> This wheel has stayed true.
>
> If this rim fails, which low profile low cost tubular rim would you
> recommend?
>
> Joakim

Velocity Escape..not box section but nice rim.

 

[jim beam]

Peter Cole wrote:
> Chalo wrote:
>> [email protected] wrote:
>>> I just noticed cracks around ALL right hand eylets on my Mavic Reflex
>>> tubular rim (32 hole, grey non-anodised). The cracks look similar to
>>> these:http://web.onetel.net.uk/~davidwgreen/rimpics/4.JPGbut some of
>>> them are from side to side and at least one was all the way to the
>>> "corner" where the side begins.
>>
>> Mavic rims made since about 1990 are well known for having problems
>> with cracking at the spoke holes and at the sidewall root.
>>
>>> Am I just unlucky, is this a poor rim type or is the tension I use too
>>> much? With lower tension I have had lot of problems with self
>>> loosening left side spokes, which required wrenching every 100-200 km.
>>> This wheel has stayed true.
>>
>> My guess is that the tension you used was too much _because_ it's a
>> poor rim.
>>
>> I have no recommendation for a good tubie rim because I don't use
>> them. If you need to use high spoke tension, be aware that aero
>> section rims are better at withstanding high spoke tension, generally
>> speaking.
>
> I had the exact same problem with the clincher version of that rim. I
> agree with Chalo, that it was a poor rim that wouldn't take the tension
> required to keep the spokes from unscrewing. I went to Open Pros after 2
> Reflex failures and didn't have the same problems.

did you use a tensiometer?

 

[jim beam]

[email protected] wrote:
> I just noticed cracks around ALL right hand eylets on my Mavic Reflex
> tubular rim (32 hole, grey non-anodised). The cracks look similar to
> these: http://web.onetel.net.uk/~davidwgreen/rimpics/4.JPG but some of
> them are from side to side and at least one was all the way to the
> "corner" where the side begins.
>
> The rim is just a couple of years old and hasn't been ridden more than
> 5000 km. I build it myself using old spokes (DT 2/1.8 mm) and rather
> high tension (the old rim had ~1300 N, this is probably about the
> same, not yet on the "taco" limit) for right hand side. I weigh 82 kg
> and ride on quite smooth roads.
>
> The old rim was an anodised GP4, which I rode about 20 000 km until
> one eylet was pulled through the rim. I hoped, that this new rim would
> be better....
>
> Am I just unlucky, is this a poor rim type or is the tension I use too
> much? With lower tension I have had lot of problems with self
> loosening left side spokes, which required wrenching every 100-200 km.
> This wheel has stayed true.
>
> If this rim fails, which low profile low cost tubular rim would you
> recommend?
>
> Joakim
>
excessive spoke tension. trying to determine spoke tension by judging
the "taco" limit is at best imprecise and always leads to excess.

build with a tensiometer and use the manufacturer specified tension.
that allows you to achieve that narrow zone of tension that avoids both
problems.

 

[[email protected]]

On 14 syys, 15:58, jim beam <[email protected]> wrote:

> excessive spoke tension. trying to determine spoke tension by judging
> the "taco" limit is at best imprecise and always leads to excess.
>
> build with a tensiometer and use the manufacturer specified tension.
> that allows you to achieve that narrow zone of tension that avoids both
> problems.

Haven't used the taco limit, just said that it hasn't been reached. I
measured the tension by sound pitch from the old rim a year or two
before it failed. With the old rim I increased the tension bit by bit
until unscrewing problem was solved. I also have one Mavic clincher
rim that suffers from unscrewing.

The current rim I tensioned to about the same tension as the old one
(a bit more tension than in the clincher rim) just by feel.

I'm not going to buy a tensiometer, since I build a new wheel only
when the previous one fails, which hopefully means once in 10-20
years. The front rim from Wolber is now 17 years and well over 30 000
km old and hasn't needed any care (it has a deeper profile and 1000 N
tension).

It's easy to notice the difference between 1000 and 1300 N just by
feel. 1000 N for the right side of rear wheel just is not enough for
my rims.

Joakim

 

[jim beam]

[email protected] wrote:
> On 14 syys, 15:58, jim beam <[email protected]> wrote:
>
>> excessive spoke tension. trying to determine spoke tension by judging
>> the "taco" limit is at best imprecise and always leads to excess.
>>
>> build with a tensiometer and use the manufacturer specified tension.
>> that allows you to achieve that narrow zone of tension that avoids both
>> problems.
>
> Haven't used the taco limit, just said that it hasn't been reached. I
> measured the tension by sound pitch from the old rim a year or two
> before it failed. With the old rim I increased the tension bit by bit
> until unscrewing problem was solved. I also have one Mavic clincher
> rim that suffers from unscrewing.
>
> The current rim I tensioned to about the same tension as the old one
> (a bit more tension than in the clincher rim) just by feel.
>
> I'm not going to buy a tensiometer, since I build a new wheel only
> when the previous one fails, which hopefully means once in 10-20
> years. The front rim from Wolber is now 17 years and well over 30 000
> km old and hasn't needed any care (it has a deeper profile and 1000 N
> tension).
>
> It's easy to notice the difference between 1000 and 1300 N just by
> feel.

how do you know those are the numbers if you're not using a
tensiometer??? you sound like a mechanic that thinks he can judge
torque - it just isn't true. buy a $60 tensiometer. set your wheels
accurately. then sell it for $50. end of problem.


> 1000 N for the right side of rear wheel just is not enough for
> my rims.
>
> Joakim
>

 

[Peter Cole]

jim beam wrote:
> Peter Cole wrote:
>> Chalo wrote:
>>> [email protected] wrote:
>>>> I just noticed cracks around ALL right hand eylets on my Mavic Reflex
>>>> tubular rim (32 hole, grey non-anodised). The cracks look similar to
>>>> these:http://web.onetel.net.uk/~davidwgreen/rimpics/4.JPGbut some of
>>>> them are from side to side and at least one was all the way to the
>>>> "corner" where the side begins.
>>>
>>> Mavic rims made since about 1990 are well known for having problems
>>> with cracking at the spoke holes and at the sidewall root.
>>>
>>>> Am I just unlucky, is this a poor rim type or is the tension I use too
>>>> much? With lower tension I have had lot of problems with self
>>>> loosening left side spokes, which required wrenching every 100-200 km.
>>>> This wheel has stayed true.
>>>
>>> My guess is that the tension you used was too much _because_ it's a
>>> poor rim.
>>>
>>> I have no recommendation for a good tubie rim because I don't use
>>> them. If you need to use high spoke tension, be aware that aero
>>> section rims are better at withstanding high spoke tension, generally
>>> speaking.
>>
>> I had the exact same problem with the clincher version of that rim. I
>> agree with Chalo, that it was a poor rim that wouldn't take the
>> tension required to keep the spokes from unscrewing. I went to Open
>> Pros after 2 Reflex failures and didn't have the same problems.
>
> did you use a tensiometer?

I didn't build that wheel, it was built by an experienced builder who
does/did have a tensiometer, I assume he used it.

 

[Ron Ruff]

On Sep 14, 2:35 am, [email protected] wrote:
> If this rim fails, which low profile low cost tubular rim would you
> recommend?

If you are willing to increase the profile a bit, the Velocity Escape
(20mm tall, 400g) or the Nio25T (25mm tall, 435g... made by Kinlin who
builds rims for Rolf and AC) are both solid rims.

 

[Colin Campbell]

Peter Cole wrote:
> Chalo wrote:
>> [email protected] wrote:
>>> I just noticed cracks around ALL right hand eylets on my Mavic Reflex
>>> tubular rim (32 hole, grey non-anodised). The cracks look similar to
>>> these:http://web.onetel.net.uk/~davidwgreen/rimpics/4.JPGbut some of
>>> them are from side to side and at least one was all the way to the
>>> "corner" where the side begins.
>>
>> Mavic rims made since about 1990 are well known for having problems
>> with cracking at the spoke holes and at the sidewall root.
>>
>>> Am I just unlucky, is this a poor rim type or is the tension I use too
>>> much? With lower tension I have had lot of problems with self
>>> loosening left side spokes, which required wrenching every 100-200 km.
>>> This wheel has stayed true.
>>
>> My guess is that the tension you used was too much _because_ it's a
>> poor rim.
>>
>> I have no recommendation for a good tubie rim because I don't use
>> them. If you need to use high spoke tension, be aware that aero
>> section rims are better at withstanding high spoke tension, generally
>> speaking.
>
> I had the exact same problem with the clincher version of that rim. I
> agree with Chalo, that it was a poor rim that wouldn't take the tension
> required to keep the spokes from unscrewing. I went to Open Pros after 2
> Reflex failures and didn't have the same problems.

I have a silver 32 spoke Open Pro sitting in my garage with 10 cracked
spoke holes. I had to replace a blue anodized Open Pro that suffered a
crack at one spoke hole. The new wheel popped three spokes before the
LBS started noticing the cracks; then careful visual inspection showed
the ten cracks.

Very disappointing!

I bought a Trek bike last year in August, and stayed with Bontrager Race
Lite wheels, even though I was afraid of problems with a 22F, 24R setup.
I've actually had no problems, except that one spoke likes to loosen
up on the rear wheel.

I don't know when or if I'll try Mavic rims again.

 

[John Thompson]

On 2007-09-14, jim beam <[email protected]> wrote:

> how do you know those are the numbers if you're not using a
> tensiometer???

How do you jknow your tensiometer is properly calibrated? That was the
problem we ran into at Trek when we started building wheels. I was
recalibrating tensiometers for the builders several times a day. Hard to
get anything else done, sometimes.

--

John ([email protected])

 

[jim beam]

Colin Campbell wrote:
> Peter Cole wrote:
>> Chalo wrote:
>>> [email protected] wrote:
>>>> I just noticed cracks around ALL right hand eylets on my Mavic Reflex
>>>> tubular rim (32 hole, grey non-anodised). The cracks look similar to
>>>> these:http://web.onetel.net.uk/~davidwgreen/rimpics/4.JPGbut some of
>>>> them are from side to side and at least one was all the way to the
>>>> "corner" where the side begins.
>>>
>>> Mavic rims made since about 1990 are well known for having problems
>>> with cracking at the spoke holes and at the sidewall root.
>>>
>>>> Am I just unlucky, is this a poor rim type or is the tension I use too
>>>> much? With lower tension I have had lot of problems with self
>>>> loosening left side spokes, which required wrenching every 100-200 km.
>>>> This wheel has stayed true.
>>>
>>> My guess is that the tension you used was too much _because_ it's a
>>> poor rim.
>>>
>>> I have no recommendation for a good tubie rim because I don't use
>>> them. If you need to use high spoke tension, be aware that aero
>>> section rims are better at withstanding high spoke tension, generally
>>> speaking.
>>
>> I had the exact same problem with the clincher version of that rim. I
>> agree with Chalo, that it was a poor rim that wouldn't take the
>> tension required to keep the spokes from unscrewing. I went to Open
>> Pros after 2 Reflex failures and didn't have the same problems.
>
> I have a silver 32 spoke Open Pro sitting in my garage with 10 cracked
> spoke holes. I had to replace a blue anodized Open Pro that suffered a
> crack at one spoke hole. The new wheel popped three spokes before the
> LBS started noticing the cracks; then careful visual inspection showed
> the ten cracks.
>
> Very disappointing!

and what is /your/ spoke tension???


>
> I bought a Trek bike last year in August, and stayed with Bontrager Race
> Lite wheels, even though I was afraid of problems with a 22F, 24R setup.
> I've actually had no problems, except that one spoke likes to loosen up
> on the rear wheel.
>
> I don't know when or if I'll try Mavic rims again.

 

[jim beam]

Peter Cole wrote:
> jim beam wrote:
>> Peter Cole wrote:
>>> Chalo wrote:
>>>> [email protected] wrote:
>>>>> I just noticed cracks around ALL right hand eylets on my Mavic Reflex
>>>>> tubular rim (32 hole, grey non-anodised). The cracks look similar to
>>>>> these:http://web.onetel.net.uk/~davidwgreen/rimpics/4.JPGbut some of
>>>>> them are from side to side and at least one was all the way to the
>>>>> "corner" where the side begins.
>>>>
>>>> Mavic rims made since about 1990 are well known for having problems
>>>> with cracking at the spoke holes and at the sidewall root.
>>>>
>>>>> Am I just unlucky, is this a poor rim type or is the tension I use too
>>>>> much? With lower tension I have had lot of problems with self
>>>>> loosening left side spokes, which required wrenching every 100-200 km.
>>>>> This wheel has stayed true.
>>>>
>>>> My guess is that the tension you used was too much _because_ it's a
>>>> poor rim.
>>>>
>>>> I have no recommendation for a good tubie rim because I don't use
>>>> them. If you need to use high spoke tension, be aware that aero
>>>> section rims are better at withstanding high spoke tension, generally
>>>> speaking.
>>>
>>> I had the exact same problem with the clincher version of that rim. I
>>> agree with Chalo, that it was a poor rim that wouldn't take the
>>> tension required to keep the spokes from unscrewing. I went to Open
>>> Pros after 2 Reflex failures and didn't have the same problems.
>>
>> did you use a tensiometer?
>
> I didn't build that wheel, it was built by an experienced builder who
> does/did have a tensiometer, I assume he used it.

you /assume/? how convenient! dodge responsibility but try to
attribute a problem to something that you're merely guessing at!

 

[jim beam]

John Thompson wrote:
> On 2007-09-14, jim beam <[email protected]> wrote:
>
>> how do you know those are the numbers if you're not using a
>> tensiometer???
>
> How do you jknow your tensiometer is properly calibrated? That was the
> problem we ran into at Trek when we started building wheels. I was
> recalibrating tensiometers for the builders several times a day. Hard to
> get anything else done, sometimes.
>

that may be, but personally, i find it hard to believe there was /that/
much of a problem. what kind of tensiometer were you using? why use
one so unreliable?

and one thing is for sure - /not/ using a tensiometer is guaranteed to
give you inconsistent results.

 

[Chalo]

jim beam wrote:
>
> Colin Campbell wrote:
> >
> > I have a silver 32 spoke Open Pro sitting in my garage with 10 cracked
> > spoke holes. I had to replace a blue anodized Open Pro that suffered a
> > crack at one spoke hole. The new wheel popped three spokes before the
> > LBS started noticing the cracks; then careful visual inspection showed
> > the ten cracks.
>
> > Very disappointing!
>
> and what is /your/ spoke tension???

I'll venture a guess: too high for Mavic's overcooked crappy alloy!
(But probably not too high for a better-made rim.)

Chalo

 

[jim beam]

Chalo wrote:
> jim beam wrote:
>> Colin Campbell wrote:
>>> I have a silver 32 spoke Open Pro sitting in my garage with 10 cracked
>>> spoke holes. I had to replace a blue anodized Open Pro that suffered a
>>> crack at one spoke hole. The new wheel popped three spokes before the
>>> LBS started noticing the cracks; then careful visual inspection showed
>>> the ten cracks.
>>> Very disappointing!
>> and what is /your/ spoke tension???
>
> I'll venture a guess: too high for Mavic's overcooked crappy alloy!
> (But probably not too high for a better-made rim.)
>
> Chalo
>

the only mavic rim i've ever succeeded in cracking is one with spoke
tension > 175N [off the end of the scale for my park tensiometer]. it's
a single eyelet x517 and i weigh #205+. perversely, i don't consider
this the result of "overcooked crappy alloy".

 

[Chalo]

jim beam wrote:
>
> Chalo wrote:
> >
> > jim beam wrote:
> >>
> >> and what is /your/ spoke tension???
> >
> > I'll venture a guess: too high for Mavic's overcooked crappy alloy!
> > (But probably not too high for a better-made rim.)
>
> the only mavic rim i've ever succeeded in cracking is one with spoke
> tension > 175N [off the end of the scale for my park tensiometer]. it's
> a single eyelet x517 and i weigh #205+. perversely, i don't consider
> this the result of "overcooked crappy alloy".

Do you mean 175kgf?

Most of Mavic's rims use 6106 aluminum-- just about the weakest of the
6000 series-- in order to get a sharp looking finish on the
extrusion. For using some of the softest structural alloy money can
buy, their rims sure don't seem very ductile. I believe they do some
monkey business with heat treatment in an attempt to buy back the
hardness sacrificed in using a weak, soft alloy. Thus they get spoke
holes that crack and sidewalls from which segments break off. I have
seen these things happen much more often with Adidas-Salomon-Mavic
rims than with all other rims combined.

Paradoxically, they seem to do this aggressive heat treatment _before_
welding, which means they get the worst of both the soft material in
the weld and the brittle material elsewhere in the rim.

Chalo