Cassette and lockring questions

[Patrick Lamb]

Had a new experience on today's ride. Shifted into high gear, and I
started freewheeling. Not good, way out in the boondocks. So I
stopped and found the lock ring holding the cassette on had unscrewed,
and the last cog had fallen outwards and lost engagement with the rest
of the cassette and the freehub. After a bit of trouble, managed to
get the lock ring screwed on finger tight (no tool or torque wrench
available along the side of the road) and continued.

Shortly before arriving back home, I looked down and noticed the right
half of the cassette was wobbling while pedalling. When I got home, I
found that the lockring was off again, which I could understand
because it wasn't screwed on tight. But to my surprise, the cassette
fell apart when I took it off the hub; there were three long, skinny
bolts holding it together, and all three of them had come unscrewed.

I didn't know they could do that. Interesting how the cassette is put
together, with plastic spacers.

Well, everything is cleaned off and put back together, but I'm a bit
nervous about riding with it. The lock ring I can understand,
although it's been OK since last summer when I repacked the bearings.
But how did the cassette come apart? And should I have used Loctite
to put it back together? How often do I need to check the cassette,
or is this a once every 9 years kind of freak occurrence?

Pat

Email address works as is.

 

[DI]

"Patrick Lamb" <[email protected]> wrote in message
news:[email protected]...
> Had a new experience on today's ride. Shifted into high gear, and I
> started freewheeling. Not good, way out in the boondocks. So I
> stopped and found the lock ring holding the cassette on had unscrewed,
> and the last cog had fallen outwards and lost engagement with the rest
> of the cassette and the freehub. After a bit of trouble, managed to
> get the lock ring screwed on finger tight (no tool or torque wrench
> available along the side of the road) and continued.
>
> Shortly before arriving back home, I looked down and noticed the right
> half of the cassette was wobbling while pedalling. When I got home, I
> found that the lockring was off again, which I could understand
> because it wasn't screwed on tight. But to my surprise, the cassette
> fell apart when I took it off the hub; there were three long, skinny
> bolts holding it together, and all three of them had come unscrewed.
>
> I didn't know they could do that. Interesting how the cassette is put
> together, with plastic spacers.
>
> Well, everything is cleaned off and put back together, but I'm a bit
> nervous about riding with it. The lock ring I can understand,
> although it's been OK since last summer when I repacked the bearings.
> But how did the cassette come apart? And should I have used Loctite
> to put it back together? How often do I need to check the cassette,
> or is this a once every 9 years kind of freak occurrence?
>
> Pat
>
> Email address works as is.

I had this happen once, but only once, never got loose again after
tightening.

 

[JeffWills]

On Apr 28, 6:42 pm, Patrick Lamb <[email protected]> wrote:
>
> Well, everything is cleaned off and put back together, but I'm a bit
> nervous about riding with it. The lock ring I can understand,
> although it's been OK since last summer when I repacked the bearings.
> But how did the cassette come apart? And should I have used Loctite
> to put it back together? How often do I need to check the cassette,
> or is this a once every 9 years kind of freak occurrence?
>
> Pat

Those three little screws serve no useful purpose on your cassette.
They're there to keep most of the cogs together and aligned when the
cassettes are installed at the factory. I've used cassettes where I've
removed those bolts and there's no difference.

Make sure the lockring is on tight enough. I tighten mine (Shimano and
SRAM steel cassettes) with a 10" adjustable wrench (no Loctite). None
has ever come loose, and I've never stripped a thread. Park recommends
30 ft-lbs of torque- I probably go higher than that, but then I'm an
old school bike mechanic:
If At First You Don't Succeed, Get a Bigger Hammer.

Jeff

 

[Gary Young]

On Sat, 28 Apr 2007 20:03:37 -0700, JeffWills wrote:

> On Apr 28, 6:42 pm, Patrick Lamb <[email protected]> wrote:
>>
>> Well, everything is cleaned off and put back together, but I'm a bit
>> nervous about riding with it. The lock ring I can understand,
>> although it's been OK since last summer when I repacked the bearings.
>> But how did the cassette come apart? And should I have used Loctite
>> to put it back together? How often do I need to check the cassette,
>> or is this a once every 9 years kind of freak occurrence?
>>
>> Pat
>
> Those three little screws serve no useful purpose on your cassette.
> They're there to keep most of the cogs together and aligned when the
> cassettes are installed at the factory. I've used cassettes where I've
> removed those bolts and there's no difference.

I've read somewhere that the screws do serve a purpose on hubs with
aluminum freewheel bodies. By keeping all of the cogs together, they
prevent individual cogs from biting into the aluminum splines.

>
> Make sure the lockring is on tight enough. I tighten mine (Shimano and
> SRAM steel cassettes) with a 10" adjustable wrench (no Loctite). None
> has ever come loose, and I've never stripped a thread. Park recommends
> 30 ft-lbs of torque- I probably go higher than that, but then I'm an
> old school bike mechanic:
> If At First You Don't Succeed, Get a Bigger Hammer.
>
> Jeff

 

[[email protected]]

On Apr 28, 7:42 pm, Patrick Lamb <[email protected]> wrote:
> Had a new experience on today's ride. Shifted into high gear, and I
> started freewheeling. Not good, way out in the boondocks. So I
> stopped and found the lock ring holding the cassette on had unscrewed,
> and the last cog had fallen outwards and lost engagement with the rest
> of the cassette and the freehub. After a bit of trouble, managed to
> get the lock ring screwed on finger tight (no tool or torque wrench
> available along the side of the road) and continued.
>
> Shortly before arriving back home, I looked down and noticed the right
> half of the cassette was wobbling while pedalling. When I got home, I
> found that the lockring was off again, which I could understand
> because it wasn't screwed on tight. But to my surprise, the cassette
> fell apart when I took it off the hub; there were three long, skinny
> bolts holding it together, and all three of them had come unscrewed.
>
> I didn't know they could do that. Interesting how the cassette is put
> together, with plastic spacers.
>
> Well, everything is cleaned off and put back together, but I'm a bit
> nervous about riding with it. The lock ring I can understand,
> although it's been OK since last summer when I repacked the bearings.
> But how did the cassette come apart? And should I have used Loctite
> to put it back together? How often do I need to check the cassette,
> or is this a once every 9 years kind of freak occurrence?

The screws holding the cassette together are not
necessary, they are mildly convenient for slipping
the unit onto the freehub. They probably vibrated
loose because your lockring's been gradually getting
loose for a while. Have your rear shifts been
imprecise lately?

If the lockring comes loose in the middle of nowhere
and you don't have a cassette tool, like most of us,
you can finger tighten it, and then tighten it further by
placing a screwdriver or other pointy object against
a spline and tapping it clockwise. This will get you
home; be attentive to noise or shifting problems that
indicate it's coming loose again.

Ben

 

[Qui si parla Campagnolo]

On Apr 29, 12:07 am, Gary Young <[email protected]> wrote:
> On Sat, 28 Apr 2007 20:03:37 -0700, JeffWills wrote:
> > On Apr 28, 6:42 pm, Patrick Lamb <[email protected]> wrote:
>
> >> Well, everything is cleaned off and put back together, but I'm a bit
> >> nervous about riding with it. The lock ring I can understand,
> >> although it's been OK since last summer when I repacked the bearings.
> >> But how did the cassette come apart? And should I have used Loctite
> >> to put it back together? How often do I need to check the cassette,
> >> or is this a once every 9 years kind of freak occurrence?
>
> >> Pat
>
> > Those three little screws serve no useful purpose on your cassette.
> > They're there to keep most of the cogs together and aligned when the
> > cassettes are installed at the factory. I've used cassettes where I've
> > removed those bolts and there's no difference.
>
> I've read somewhere that the screws do serve a purpose on hubs with
> aluminum freewheel bodies. By keeping all of the cogs together, they
> prevent individual cogs from biting into the aluminum splines.
>
>
>
> > Make sure the lockring is on tight enough. I tighten mine (Shimano and
> > SRAM steel cassettes) with a 10" adjustable wrench (no Loctite). None
> > has ever come loose, and I've never stripped a thread. Park recommends
> > 30 ft-lbs of torque- I probably go higher than that, but then I'm an
> > old school bike mechanic:
> > If At First You Don't Succeed, Get a Bigger Hammer.
>
> > Jeff

Nope, just there for the factory, ,to make it easier to install..TIGHT
lockring, with a bit of grasso on the outside of the freehub body and
grease the threads of the lockring..TIGHT-I think Campag's says 50nm...

 

[A Muzi]

The three 3mm screws/pins are _only_ for the convenience of the
assembler - throw them away with impunity.

Take a moment to wipe any accumulated grit from the cogs/spacers/body.
Lube the lockring and note the torque spec stamped on its face - this is
not a test of strength, 15~40 Nm is adequate.

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

Patrick Lamb wrote:
> Had a new experience on today's ride. Shifted into high gear, and I
> started freewheeling. Not good, way out in the boondocks. So I
> stopped and found the lock ring holding the cassette on had unscrewed,
> and the last cog had fallen outwards and lost engagement with the rest
> of the cassette and the freehub. After a bit of trouble, managed to
> get the lock ring screwed on finger tight (no tool or torque wrench
> available along the side of the road) and continued.
>
> Shortly before arriving back home, I looked down and noticed the right
> half of the cassette was wobbling while pedalling. When I got home, I
> found that the lockring was off again, which I could understand
> because it wasn't screwed on tight. But to my surprise, the cassette
> fell apart when I took it off the hub; there were three long, skinny
> bolts holding it together, and all three of them had come unscrewed.
>
> I didn't know they could do that. Interesting how the cassette is put
> together, with plastic spacers.
>
> Well, everything is cleaned off and put back together, but I'm a bit
> nervous about riding with it. The lock ring I can understand,
> although it's been OK since last summer when I repacked the bearings.
> But how did the cassette come apart? And should I have used Loctite
> to put it back together? How often do I need to check the cassette,
> or is this a once every 9 years kind of freak occurrence?

 

[Patrick Lamb]

On 28 Apr 2007 20:03:37 -0700, JeffWills <[email protected]> wrote:
>On Apr 28, 6:42 pm, Patrick Lamb <[email protected]> wrote:
>> Well, everything is cleaned off and put back together, but I'm a bit
>> nervous about riding with it. The lock ring I can understand,
>> although it's been OK since last summer when I repacked the bearings.
>> But how did the cassette come apart? And should I have used Loctite
>> to put it back together? How often do I need to check the cassette,
>> or is this a once every 9 years kind of freak occurrence?
>
>Those three little screws serve no useful purpose on your cassette.
>They're there to keep most of the cogs together and aligned when the
>cassettes are installed at the factory. I've used cassettes where I've
>removed those bolts and there's no difference.

One more question I meant to ask was, is there any significance to all
of these coming loose at the same time?

>Make sure the lockring is on tight enough. I tighten mine (Shimano and
>SRAM steel cassettes) with a 10" adjustable wrench (no Loctite). None
>has ever come loose, and I've never stripped a thread. Park recommends
>30 ft-lbs of torque- I probably go higher than that, but then I'm an
>old school bike mechanic:
>If At First You Don't Succeed, Get a Bigger Hammer.

Ah, is that the school where you learn to tighten it until it strips,
then stop 1/4 turn earlier next time?
(I like the 12" crescent wrench, probably because it's the biggest one
I've got.)

Pat

Email address works as is.

 

[Patrick Lamb]

On 28 Apr 2007 23:16:39 -0700, "[email protected]"
<[email protected]> wrote:
>On Apr 28, 7:42 pm, Patrick Lamb <[email protected]> wrote:
>> Had a new experience on today's ride. Shifted into high gear, and I
>> started freewheeling. Not good, way out in the boondocks. So I
>> stopped and found the lock ring holding the cassette on had unscrewed,
>> and the last cog had fallen outwards and lost engagement with the rest
>> of the cassette and the freehub. After a bit of trouble, managed to
>> get the lock ring screwed on finger tight (no tool or torque wrench
>> available along the side of the road) and continued.
>>
>> Shortly before arriving back home, I looked down and noticed the right
>> half of the cassette was wobbling while pedalling. When I got home, I
>> found that the lockring was off again, which I could understand
>> because it wasn't screwed on tight. But to my surprise, the cassette
>> fell apart when I took it off the hub; there were three long, skinny
>> bolts holding it together, and all three of them had come unscrewed.
>>
>> I didn't know they could do that. Interesting how the cassette is put
>> together, with plastic spacers.
>>
>> Well, everything is cleaned off and put back together, but I'm a bit
>> nervous about riding with it. The lock ring I can understand,
>> although it's been OK since last summer when I repacked the bearings.
>> But how did the cassette come apart? And should I have used Loctite
>> to put it back together? How often do I need to check the cassette,
>> or is this a once every 9 years kind of freak occurrence?
>
>The screws holding the cassette together are not
>necessary, they are mildly convenient for slipping
>the unit onto the freehub. They probably vibrated
>loose because your lockring's been gradually getting
>loose for a while. Have your rear shifts been
>imprecise lately?

Shucks, you heard that? I thought I was cussing under my breath.

>If the lockring comes loose in the middle of nowhere
>and you don't have a cassette tool, like most of us,
>you can finger tighten it, and then tighten it further by
>placing a screwdriver or other pointy object against
>a spline and tapping it clockwise. This will get you
>home; be attentive to noise or shifting problems that
>indicate it's coming loose again.

Thanks for the tip. Don't know if it would have helped, I was in the
middle of one of those political dreamers' industrial parks; nothing
bigger than some gravel to hit it with.

Pat

Email address works as is.

 

[Patrick Lamb]

On Sun, 29 Apr 2007 14:20:15 -0500, A Muzi <[email protected]>
wrote:
>Take a moment to wipe any accumulated grit from the cogs/spacers/body.
>Lube the lockring and note the torque spec stamped on its face - this is
>not a test of strength, 15~40 Nm is adequate.

I did the cleaning, probably the cleanest non-new cassette I've had on
a bike when I got done. Lessee, 22 ft-lb is about a good hefty pull
on the end of a 12" wrench without yanking hard on it, right?

Pat

Email address works as is.