Cassette won't fit on freewheel any more: bizarre!

[Derk]

Hi,

I took a 9S 105 13-23 cassette off my Ultegra 10S hub and I couldn't fit it
back on any more. I tried a new 9S Ultegra and a new 105 casette and these
fit like a glove on the same freehub.

I can't figure out why the fairly new cassette I removed won't slide all the
way over the freehub. I see no anormalities inside the cogs and the
cassette is clean.

Any ideas?

Gr, Derk

 

[Derk]

Stephen Greenwood wrote:

> I don't know about your hub, but I had this problem once with a freehub
> body made of aluminum.
It's a nearly new hub. It's absolutely undamaged. The only cassette that
won't fit is the one I took off yesterday. All other cassettes that I have
here fit without a problem....

> The steel cassette created small notches in the
> soft freehub body. Filing them down solved the problem.
I know that can happen, but this hub is undamaged.

> Using aluminum for that part had no real advantage save perhaps some
> negligible weight decrease
Just like frames!

Greets, Derk

 

[bfd]

Derk wrote:
> Stephen Greenwood wrote:
>
> > I don't know about your hub, but I had this problem once with a freehub
> > body made of aluminum.
> It's a nearly new hub. It's absolutely undamaged. The only cassette that
> won't fit is the one I took off yesterday. All other cassettes that I have
> here fit without a problem....
>
> > The steel cassette created small notches in the
> > soft freehub body. Filing them down solved the problem.
> I know that can happen, but this hub is undamaged.
>
So if the *only* cassette that won't fit on your freehub is that one
steel cassette, have you inspected it? Maybe you some how damaged the
cassette. Alternatively, have you tried mounting that cassette onto
another freehub body?

Cassettes are relatively cheap, they're consumables, so if that one
particular cassette doesn't fit, use another.

 

[[email protected]]

On 6 Oct 2006 13:23:42 -0700, "bfd" <[email protected]> wrote:

>
>Derk wrote:
>> Stephen Greenwood wrote:
>>
>> > I don't know about your hub, but I had this problem once with a freehub
>> > body made of aluminum.
>> It's a nearly new hub. It's absolutely undamaged. The only cassette that
>> won't fit is the one I took off yesterday. All other cassettes that I have
>> here fit without a problem....
>>
>> > The steel cassette created small notches in the
>> > soft freehub body. Filing them down solved the problem.
>> I know that can happen, but this hub is undamaged.
>>
>So if the *only* cassette that won't fit on your freehub is that one
>steel cassette, have you inspected it? Maybe you some how damaged the
>cassette. Alternatively, have you tried mounting that cassette onto
>another freehub body?
>
>Cassettes are relatively cheap, they're consumables, so if that one
>particular cassette doesn't fit, use another.

Dear BFD,

True, other cassettes work, so the problem is easily solved.

But how the hell do you damage a reasonably new cassette so that it
won't fit back over the hub?

If someone like me had posted the question, dismissing it would be
quite sensible. My first thought was to ask if Derk had tried putting
the cassette on upside-down to see if it would fit part-way on, but
luckily it occurred to me that the spline pattern is asymmetrical and
the idea would never work, so no one will know just how dumb I--

Anyway, Derk strikes me as a fairly competent poster when it comes to
such matters, so I'm very curious to know what happened. If such
things can happen to posters like him, it will be good for posters
like me to learn painlessly how to avoid it.

Somehow I doubt that Derk took the cassette apart and reassembled all
the cogs and reassembled them bottom-side up. (I once put the front
wheels back on a Dodge army ambulance with the dishing outward instead
of inward, so I'm more alert to such mistakes than posters of normal
intelligence.)

I liked Stephen's idea of hard steel notching soft aluminum, but Derk
replied that this isn't the problem.

Cheers,

Carl Fogel

 

[M-gineering]

Derk wrote:

> I don't see any damage on the inside of the cassette. I tried to take it
> apart, but I can't fit a hex wrench to open the cogs that are fixed
> together with 3 tiny hex bolts.......

Invest in a proper (eg PB) set of hex keys then. In all probability one
of the cogs has shifted slightly (to fit in a detent of the too soft
aluminium hubbody you had it previously fitted too)) causing it not to
fit on a properly designed and machined freehub
--
---
Marten Gerritsen

INFOapestaartjeM-GINEERINGpuntNL
www.m-gineering.nl

 

[Derk]

[email protected] wrote:

> I liked Stephen's idea of hard steel notching soft aluminum, but Derk
> replied that this isn't the problem.
I have one theory, but I don't know if it makes any sence: I put that
cassette from my "new" DT Wheelset on an older CXP33 wheelset. I used to
put loose 8 speed cogs on that freewheel hub and that one has notches
caused by the loose cogs.

After that one ride I decided I preferred to put that cassette back on the
DT freewheel. Could it be possible that during that one ride, during which
I did interval training, the "new" cassette was deformed by the notches of
the old freewheel?
I don't see any damage on the inside of the cassette. I tried to take it
apart, but I can't fit a hex wrench to open the cogs that are fixed
together with 3 tiny hex bolts.......

Gr, Derk

 

[Derk]

M-gineering wrote:

> Invest in a proper (eg PB) set of hex keys then.
I have a set of Parktool hex wrenches.....

> In all probability one
> of the cogs has shifted slightly (to fit in a detent of the too soft
> aluminium hubbody you had it previously fitted too)) causing it not to
> fit on a properly designed and machined freehub
I think so too.

Gr, Derk

 

[Derk]

Marten wrote:
> In all probability one of the cogs has shifted slightly

MArten was right! I just found another tiny hex wrench that fits. I unscred
the hex bolts slightly and it now fits on the freehub body again.

I am amazed one 55 km ride with the cassette on a slightly dented freehub
was enough to cause 1 cog to shift slightly, whilst it is part of a cog
package that's held together with 3 hexscrews.

Thanks!

Derk

 

[[email protected]]

On Sat, 07 Oct 2006 12:45:00 +0200, Derk <[email protected]> wrote:

>Marten wrote:
>> In all probability one of the cogs has shifted slightly
>
>MArten was right! I just found another tiny hex wrench that fits. I unscred
>the hex bolts slightly and it now fits on the freehub body again.
>
>I am amazed one 55 km ride with the cassette on a slightly dented freehub
>was enough to cause 1 cog to shift slightly, whilst it is part of a cog
>package that's held together with 3 hexscrews.
>
>Thanks!
>
>Derk

Dear Derk,

I'm still puzzled.

Unless it was the outermost cog that shifted, how could you pull the
cassette off the original hub?

That is, if one or more cogs had twisted out of alignment with the
others by biting into the aluminum hub to different depths, shouldn't
that have prevented the whole cassette from pulling straight off the
hub? They would have formed a very short version of a screw.

Cheers,

Carl Fogel

 

[M-gineering]

[email protected] wrote:

>
> Unless it was the outermost cog that shifted, how could you pull the
> cassette off the original hub?
>
> That is, if one or more cogs had twisted out of alignment with the
> others by biting into the aluminum hub to different depths, shouldn't
> that have prevented the whole cassette from pulling straight off the
> hub? They would have formed a very short version of a screw.

The aluminium hub probably has wider grooves (more play) than the original

--
---
Marten Gerritsen

INFOapestaartjeM-GINEERINGpuntNL
www.m-gineering.nl

 

[Derk]

[email protected] wrote:
> I'm still puzzled.
So am I!

> Unless it was the outermost cog that shifted, how could you pull the
> cassette off the original hub?
Without a problem! That's the weird part. That's why I couldn't believe
anything was wrong with the cassette. You're quite right!

> That is, if one or more cogs had twisted out of alignment with the
> others by biting into the aluminum hub to different depths, shouldn't
> that have prevented the whole cassette from pulling straight off the
> hub?
Yes. But I couldn't fit it back on the freewheel any more. I tried some new
8s and 9s cassettes on that same freewheel without a problem, but I
couldn't fit that "old" one.

I'm as puzzled as you are. Still, loosening those hexscrews allowed me to
fit it to the same freewheel again, so it must have been the cassette.

I share your way of reasoning, though.

Derk

 

[R Brickston]

On Sat, 07 Oct 2006 20:29:50 +0200, Derk <[email protected]> wrote:

>[email protected] wrote:
>> I'm still puzzled.
>So am I!
>
>> Unless it was the outermost cog that shifted, how could you pull the
>> cassette off the original hub?
>Without a problem! That's the weird part. That's why I couldn't believe
>anything was wrong with the cassette. You're quite right!
>
>> That is, if one or more cogs had twisted out of alignment with the
>> others by biting into the aluminum hub to different depths, shouldn't
>> that have prevented the whole cassette from pulling straight off the
>> hub?
>Yes. But I couldn't fit it back on the freewheel any more. I tried some new
>8s and 9s cassettes on that same freewheel without a problem, but I
>couldn't fit that "old" one.
>
>I'm as puzzled as you are. Still, loosening those hexscrews allowed me to
>fit it to the same freewheel again, so it must have been the cassette.
>
>I share your way of reasoning, though.
>
>Derk

I think you simply had the cassettes plates and spacers twisted a
little. The three screws are just there to make it easier to stick all
the cogs and spacers on the freewheel. Some sram models come with just
one screw and the whole assembly kind of flops around when its off the
freewheel.

 

[[email protected]]

On Sat, 07 Oct 2006 19:04:40 GMT, R Brickston
<rb20170REMOVE.yahoo.com@> wrote:

>On Sat, 07 Oct 2006 20:29:50 +0200, Derk <[email protected]> wrote:
>
>>[email protected] wrote:
>>> I'm still puzzled.
>>So am I!
>>
>>> Unless it was the outermost cog that shifted, how could you pull the
>>> cassette off the original hub?
>>Without a problem! That's the weird part. That's why I couldn't believe
>>anything was wrong with the cassette. You're quite right!
>>
>>> That is, if one or more cogs had twisted out of alignment with the
>>> others by biting into the aluminum hub to different depths, shouldn't
>>> that have prevented the whole cassette from pulling straight off the
>>> hub?
>>Yes. But I couldn't fit it back on the freewheel any more. I tried some new
>>8s and 9s cassettes on that same freewheel without a problem, but I
>>couldn't fit that "old" one.
>>
>>I'm as puzzled as you are. Still, loosening those hexscrews allowed me to
>>fit it to the same freewheel again, so it must have been the cassette.
>>
>>I share your way of reasoning, though.
>>
>>Derk
>
>I think you simply had the cassettes plates and spacers twisted a
>little. The three screws are just there to make it easier to stick all
>the cogs and spacers on the freewheel. Some sram models come with just
>one screw and the whole assembly kind of flops around when its off the
>freewheel.

Dear R.,

So the cassette may have been pulled off normally and would have gone
back onto the hub . . .

But while the cassette was off it somehow got a little twisted (or
maybe even was twisted as it was coming off the hub) because the
screws aren't really meant to hold it rigidly together.

So a tiny twist would goof things up almost invisibly, but easing the
screws off would let the assembly untwist and slip back onto the hub.

Right?

Cheers,

Carl Fogel

 

[R Brickston]

On Sat, 07 Oct 2006 13:32:29 -0600, [email protected] wrote:

>On Sat, 07 Oct 2006 19:04:40 GMT, R Brickston
><rb20170REMOVE.yahoo.com@> wrote:
>
>>On Sat, 07 Oct 2006 20:29:50 +0200, Derk <[email protected]> wrote:
>>
>>>[email protected] wrote:
>>>> I'm still puzzled.
>>>So am I!
>>>
>>>> Unless it was the outermost cog that shifted, how could you pull the
>>>> cassette off the original hub?
>>>Without a problem! That's the weird part. That's why I couldn't believe
>>>anything was wrong with the cassette. You're quite right!
>>>
>>>> That is, if one or more cogs had twisted out of alignment with the
>>>> others by biting into the aluminum hub to different depths, shouldn't
>>>> that have prevented the whole cassette from pulling straight off the
>>>> hub?
>>>Yes. But I couldn't fit it back on the freewheel any more. I tried some new
>>>8s and 9s cassettes on that same freewheel without a problem, but I
>>>couldn't fit that "old" one.
>>>
>>>I'm as puzzled as you are. Still, loosening those hexscrews allowed me to
>>>fit it to the same freewheel again, so it must have been the cassette.
>>>
>>>I share your way of reasoning, though.
>>>
>>>Derk
>>
>>I think you simply had the cassettes plates and spacers twisted a
>>little. The three screws are just there to make it easier to stick all
>>the cogs and spacers on the freewheel. Some sram models come with just
>>one screw and the whole assembly kind of flops around when its off the
>>freewheel.
>
>Dear R.,
>
>So the cassette may have been pulled off normally and would have gone
>back onto the hub . . .
>
>But while the cassette was off it somehow got a little twisted (or
>maybe even was twisted as it was coming off the hub) because the
>screws aren't really meant to hold it rigidly together.
>
>So a tiny twist would goof things up almost invisibly, but easing the
>screws off would let the assembly untwist and slip back onto the hub.
>
>Right?

Well, let me think about that Carl... Hmm... Ok, how about:

I think you simply had the cassettes plates and spacers twisted a
little. The three screws are just there to make it easier to stick all
the cogs and spacers on the freewheel. Some sram models come with just
one screw and the whole assembly kind of flops around when its off the
freewheel.

Is that in agreement with your observations?

 

[Derk]

M-gineering wrote:

> The aluminium hub probably has wider grooves (more play) than the original
Both are Ultegra hubs....

Derk

 

[[email protected]]

On Sat, 07 Oct 2006 19:46:02 GMT, R Brickston
<rb20170REMOVE.yahoo.com@> wrote:

>On Sat, 07 Oct 2006 13:32:29 -0600, [email protected] wrote:
>
>>On Sat, 07 Oct 2006 19:04:40 GMT, R Brickston
>><rb20170REMOVE.yahoo.com@> wrote:
>>
>>>On Sat, 07 Oct 2006 20:29:50 +0200, Derk <[email protected]> wrote:
>>>
>>>>[email protected] wrote:
>>>>> I'm still puzzled.
>>>>So am I!
>>>>
>>>>> Unless it was the outermost cog that shifted, how could you pull the
>>>>> cassette off the original hub?
>>>>Without a problem! That's the weird part. That's why I couldn't believe
>>>>anything was wrong with the cassette. You're quite right!
>>>>
>>>>> That is, if one or more cogs had twisted out of alignment with the
>>>>> others by biting into the aluminum hub to different depths, shouldn't
>>>>> that have prevented the whole cassette from pulling straight off the
>>>>> hub?
>>>>Yes. But I couldn't fit it back on the freewheel any more. I tried some new
>>>>8s and 9s cassettes on that same freewheel without a problem, but I
>>>>couldn't fit that "old" one.
>>>>
>>>>I'm as puzzled as you are. Still, loosening those hexscrews allowed me to
>>>>fit it to the same freewheel again, so it must have been the cassette.
>>>>
>>>>I share your way of reasoning, though.
>>>>
>>>>Derk
>>>
>>>I think you simply had the cassettes plates and spacers twisted a
>>>little. The three screws are just there to make it easier to stick all
>>>the cogs and spacers on the freewheel. Some sram models come with just
>>>one screw and the whole assembly kind of flops around when its off the
>>>freewheel.
>>
>>Dear R.,
>>
>>So the cassette may have been pulled off normally and would have gone
>>back onto the hub . . .
>>
>>But while the cassette was off it somehow got a little twisted (or
>>maybe even was twisted as it was coming off the hub) because the
>>screws aren't really meant to hold it rigidly together.
>>
>>So a tiny twist would goof things up almost invisibly, but easing the
>>screws off would let the assembly untwist and slip back onto the hub.
>>
>>Right?
>
>Well, let me think about that Carl... Hmm... Ok, how about:
>
>I think you simply had the cassettes plates and spacers twisted a
>little. The three screws are just there to make it easier to stick all
>the cogs and spacers on the freewheel. Some sram models come with just
>one screw and the whole assembly kind of flops around when its off the
>freewheel.
>
>Is that in agreement with your observations?

Dear R.,

Yes, thanks--I think that I'm following you and that your idea makes
sense.

Cheers,

Carl Fogel

 

[R Brickston]

On Sat, 07 Oct 2006 14:22:06 -0600, [email protected] wrote:

>On Sat, 07 Oct 2006 19:46:02 GMT, R Brickston
><rb20170REMOVE.yahoo.com@> wrote:
>
>>On Sat, 07 Oct 2006 13:32:29 -0600, [email protected] wrote:
>>
>>>On Sat, 07 Oct 2006 19:04:40 GMT, R Brickston
>>><rb20170REMOVE.yahoo.com@> wrote:
>>>
>>>>On Sat, 07 Oct 2006 20:29:50 +0200, Derk <[email protected]> wrote:
>>>>
>>>>>[email protected] wrote:
>>>>>> I'm still puzzled.
>>>>>So am I!
>>>>>
>>>>>> Unless it was the outermost cog that shifted, how could you pull the
>>>>>> cassette off the original hub?
>>>>>Without a problem! That's the weird part. That's why I couldn't believe
>>>>>anything was wrong with the cassette. You're quite right!
>>>>>
>>>>>> That is, if one or more cogs had twisted out of alignment with the
>>>>>> others by biting into the aluminum hub to different depths, shouldn't
>>>>>> that have prevented the whole cassette from pulling straight off the
>>>>>> hub?
>>>>>Yes. But I couldn't fit it back on the freewheel any more. I tried some new
>>>>>8s and 9s cassettes on that same freewheel without a problem, but I
>>>>>couldn't fit that "old" one.
>>>>>
>>>>>I'm as puzzled as you are. Still, loosening those hexscrews allowed me to
>>>>>fit it to the same freewheel again, so it must have been the cassette.
>>>>>
>>>>>I share your way of reasoning, though.
>>>>>
>>>>>Derk
>>>>
>>>>I think you simply had the cassettes plates and spacers twisted a
>>>>little. The three screws are just there to make it easier to stick all
>>>>the cogs and spacers on the freewheel. Some sram models come with just
>>>>one screw and the whole assembly kind of flops around when its off the
>>>>freewheel.
>>>
>>>Dear R.,
>>>
>>>So the cassette may have been pulled off normally and would have gone
>>>back onto the hub . . .
>>>
>>>But while the cassette was off it somehow got a little twisted (or
>>>maybe even was twisted as it was coming off the hub) because the
>>>screws aren't really meant to hold it rigidly together.
>>>
>>>So a tiny twist would goof things up almost invisibly, but easing the
>>>screws off would let the assembly untwist and slip back onto the hub.
>>>
>>>Right?
>>
>>Well, let me think about that Carl... Hmm... Ok, how about:
>>
>>I think you simply had the cassettes plates and spacers twisted a
>>little. The three screws are just there to make it easier to stick all
>>the cogs and spacers on the freewheel. Some sram models come with just
>>one screw and the whole assembly kind of flops around when its off the
>>freewheel.
>>
>>Is that in agreement with your observations?
>
>Dear R.,
>
>Yes, thanks--I think that I'm following you and that your idea makes
>sense.
>
>Cheers,
>
>Carl Fogel

Well, just so we cover all bases, we should consider this entirely
different and alternative theory which I know is probably in /total/
disagreement with what I first said:

So the cassette may have been pulled off normally and would have gone
back onto the hub . . .

But while the cassette was off it somehow got a little twisted (or
maybe even was twisted as it was coming off the hub) because the
screws aren't really meant to hold it rigidly together.

So a tiny twist would goof things up almost invisibly, but easing the
screws off would let the assembly untwist and slip back onto the hub.

Right?

 

[Derk]

R Brickston wrote:
> But while the cassette was off it somehow got a little twisted (or
> maybe even was twisted as it was coming off the hub) because the
> screws aren't really meant to hold it rigidly together.
I tried to put the cassette back on the hub while pushing it from right to
left, hoping I could force the cogs back into perfect alignment, but I was
unable to do this. Therefore I conclude that considerable force is
necessary to misalign the cogs.

Maybe tolerances of the 9S body are less than machining tolerances of the
new 10S freewheel body? (I took it off a 9S and rode 50 km with the
cassette on a slightly dented 9S body and was unable to put it back on the
10S body)

Gr, Derk