Cassette failure modes (and repair)

[Zaf]

I was humping up a steep hill last night and I managed to break loose the 21& 23 tooth cogs from my
cassette. I would never have guessed this possible with a recreational rider. It was an ultegra
cassette with ~5000 miles on it. As the metal attaching it to the spider thingy was sheared it is
not a matter of repinning it. Is is possible to purchase just the spider section?

 

[Wiscottsin]

"Zaf" <[email protected]> wrote in message news:[email protected]...
> I was humping up a steep hill last night and I managed to break loose the 21& 23 tooth cogs from
> my cassette. I would never have guessed this possible with a recreational rider. It was an ultegra
> cassette with ~5000 miles on it. As the metal attaching it to the spider thingy was sheared it is
> not a matter of repinning it. Is is possible to purchase just the spider section?

AFAIK, no

If you broke 2 of them, chances are more are bound to break soon. I'd replace the whole cassette as
they are relatively inexpensive. Replace your chain at the same time, also good preventative
maintenance. If you haven't replaced the chain for a while it can stretch. And if you use the old
chain with new cogs, slipping can occur under high peddling load.

 

[Qui Si Parla Ca]

<< It was an ultegra cassette
> with ~5000 miles on it. As the metal attaching it to the spider thingy was sheared it is not a
> matter of repinning it. Is is possible to purchase just the spider section?

Nope but use a 105 level cogset, loose cogs...cheaper also-

Peter Chisholm Vecchio's Bicicletteria 1833 Pearl St. Boulder, CO, 80302
(303)440-3535 http://www.vecchios.com "Ruote convenzionali costruite eccezionalmente bene"

 

[Doug Goodwin]

[email protected] (Zaf) wrote in news:[email protected]:

> I was humping up a steep hill last night and I managed to break loose the 21& 23 tooth cogs from
> my cassette. I would never have guessed this possible with a recreational rider. It was an ultegra
> cassette with ~5000 miles on it. As the metal attaching it to the spider thingy was sheared it is
> not a matter of repinning it. Is is possible to purchase just the spider section?

QBP lists the various Shimano spider assemblies in their catalog. Talk to your LBS [ain't
cheap though!].

Or, do like Mr. Chisholm suggests and get a 105 cassette. As he notes, cheaper [a helluva a lot so],
and you can unpin the cogs. I've collected a bag full of various ones from catalog sales, swap
meeets, etc., and now "roll my own" cogsets, changing out depending on the ride.

--
Doug Goodwin YMMV

"We have met the enemy, and they is us." - Pogo __o _`\<,_ (*)/ (*)

 

[Anonymous]

>I was humping up a steep hill last night and I managed to break loose the 21& 23 tooth cogs from my
>cassette.

What happened the moment it occurred? Were you sitting or standing? Did you lose balance, jolt a
knee, what?

Doug

 

[Zaf]

"WiScottsin" <[email protected]> wrote in message news:<[email protected]>...
> "Zaf" <[email protected]> wrote in message news:[email protected]...
> > I was humping up a steep hill last night and I managed to break loose the 21& 23 tooth cogs from
> > my cassette. I would never have guessed this possible with a recreational rider. It was an
> > ultegra cassette with ~5000 miles on it. As the metal attaching it to the spider thingy was
> > sheared it is not a matter of repinning it. Is is possible to purchase just the spider section?
>
> AFAIK, no
>
> If you broke 2 of them, chances are more are bound to break soon. I'd replace the whole cassette
> as they are relatively inexpensive. Replace your chain at the same time, also good preventative
> maintenance. If you haven't replaced the chain for a while it can stretch. And if you use the old
> chain with new cogs, slipping can occur under high peddling load.

Well the spider is the weak link, so I would not think the failure of the spine attached cogs would
be a problem. The chain is already pretty new. The suggestion for the 105 cassette is a good one,
get rid of the spider altogether.

And to answer the other Dougs question: I was sitting, the breaking of the cassete did not in itself
cause much disruption, but the immediate loss of power stopped me pretty quick!