Transmition slips....

Corsaire <[email protected]> writes:

> when going uphill. As I push the pedal forward it feels as if something gives and slips forward...
> CLUNK!....like something didn't grab or so.,... What is it??? I checked the teeth on the
> transmition looks fine, the chain doesn't look worn out - is it the chain or the tooth on the gear
> that is wearing out???? Please help...it didn't do it before this last weekend! Corsaire

Does it happen in only one or two gears, or in several gears? How old is the bike, how old is the
chain, and how much do you ride?

My guess is you need a new cassette and a new chain.

Corsaire <[email protected]> wrote:
> when going uphill. As I push the pedal forward it feels as if something gives and slips forward...
> CLUNK!....like something didn't grab or so.,... What is it??? I checked the teeth on the
> transmition looks fine, the chain doesn't look worn out - is it the chain or the tooth on the gear
> that is wearing out???? Please help...it didn't do it before this last weekend! Corsaire

Assuming this is a derailleur type system (as opposed to internal hub gear like Sturmey Archer), the
problem is either a slipping chain due to excess wear on the rear gears, front chainrings, or chain.
OR the pawls in your freewheel/freehub are not engaging.

Another possibility is that you are using a new chain on a worn cassette.

To check the chain, measure the length of 12 complete links. When new, that will measure exactly 12
inches. If it has elongated to 12-1/16 inches or more, the chain needs replacing.

Worn gears will have pointy tips, and a hook shape where the chain bears on them.

Art Harris

Corsaire <[email protected]> wrote:
: when going uphill. As I push the pedal forward it feels as if something gives and slips forward...
: CLUNK!....like something didn't grab or so.,... What is it??? I checked the teeth on the
: transmition looks fine, the chain doesn't look worn out - is it the chain or the tooth on the gear
: that is wearing out???? Please help...it didn't do it before this last weekend! Corsaire

Could be your cassette lock ring is loose.

--------------------------------
Bob Masse' [email protected]
--------------------------------

"Corsaire" <[email protected]> wrote in message news:[email protected]
> when going uphill. As I push the pedal forward it feels as if something gives and slips forward...
> CLUNK!....like something didn't grab or so.,... What is it??? I checked the teeth on the
> transmition looks fine, the chain doesn't look worn out - is it the chain or the tooth on the gear
> that is wearing out???? Please help...it didn't do it before this last weekend! Corsaire
>
>
Could also be that the bike needs cleaning. I had chain skipping with a new chain and cassette after
a long (dirty) trip. Went away completely after I cleaned and lubed the chain, adjusted the
derailer, and cleaned out the derailer cable where it goes under the BB shell..

Corsaire <[email protected]> wrote in message
news:<[email protected]>...
> when going uphill. As I push the pedal forward it feels as if something gives and slips forward...
> CLUNK!....like something didn't grab or so.,... What is it??? I checked the teeth on the
> transmition looks fine, the chain doesn't look worn out - is it the chain or the tooth on the gear
> that is wearing out???? Please help...it didn't do it before this last weekend! Corsaire

Is this a freewheel or cassette? If freewheel, you might try swapping on an old one from your LBS's
junk bin. This year, I've gone through two of them--it's as though the ratcheting mechanism is just
so worn that it slips under high torque.

On Tue, 25 Nov 2003 15:12:51 GMT, Harris <[email protected]> wrote:
>
> To check the chain, measure the length of 12 complete links. When new, that will measure exactly
> 12 inches. If it has elongated to 12-1/16 inches or more, the chain needs replacing.

I've read advice like this in a couple of bike maintenance books and/or bike magazines. I thought
that a stretched chain can cause slippage. However, my 12+ year old Suntour (remember them?) chain
measures 11 1/4" over eleven links. (I didn't feel like removing the chain to measure a twelfth
link.) That is well stretched by any standard that I've seen, including the one above.

I have gotten the occasional "clunk" from the rear hub area, accompanied by about 1/4 of a rotation
at the pedals, but that's only three times a year or so.

So I've gotta ask, what's the point of being concerned with a stretched chain, in this or in any
situation?

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__/_ _ _ _) /(- \/(- _) .
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On Sat, 29 Nov 2003 21:43:41 -0500, Steve Sanfratello <[email protected]> wrote:

>On Tue, 25 Nov 2003 15:12:51 GMT, Harris <[email protected]> wrote:
>>
>> To check the chain, measure the length of 12 complete links. When new, that will measure exactly
>> 12 inches. If it has elongated to 12-1/16 inches or more, the chain needs replacing.
>
>I've read advice like this in a couple of bike maintenance books and/or bike magazines. I thought
>that a stretched chain can cause slippage. However, my 12+ year old Suntour (remember them?) chain
>measures 11 1/4" over eleven links. (I didn't feel like removing the chain to measure a twelfth
>link.) That is well stretched by any standard that I've seen, including the one above.
>
>I have gotten the occasional "clunk" from the rear hub area, accompanied by about 1/4 of a rotation
>at the pedals, but that's only three times a year or so.
>
>So I've gotta ask, what's the point of being concerned with a stretched chain, in this or in any
>situation?

A "stretched", or more accurately "worn" chain where the pins are further apart than the specified
1/2" will seem to work fairly well with the currenct chainrings and cassette since they will wear
to match the chain spacing. However, when you replace your chain with a shiny new one, the
cassette and chainrings (more expensive than the chain no doubt) will be worn too much and will
not work smoothly.

Its a matter of preventive maintenance. Replace the chain every once in a while and extend the life
of the cassette and chainrings greatly.

In article <[email protected]>, nevets72 @nospamingme.linuxmail.org says...
> On Tue, 25 Nov 2003 15:12:51 GMT, Harris <[email protected]> wrote:
> >
> > To check the chain, measure the length of 12 complete links. When new, that will measure exactly
> > 12 inches. If it has elongated to 12-1/16 inches or more, the chain needs replacing.
>
> I've read advice like this in a couple of bike maintenance books and/or bike magazines. I thought
> that a stretched chain can cause slippage. However, my 12+ year old Suntour (remember them?) chain
> measures 11 1/4" over eleven links. (I didn't feel like removing the chain to measure a twelfth
> link.) That is well stretched by any standard that I've seen, including the one above.
>
> I have gotten the occasional "clunk" from the rear hub area, accompanied by about 1/4 of a
> rotation at the pedals, but that's only three times a year or so.
>
> So I've gotta ask, what's the point of being concerned with a stretched chain, in this or in any
> situation?

If you now go back and replace either the cluster or the chain, you will have to do the other as
well. That's the only issue. Right now, your cluster and chain fit each other, because the cluster
has worn to fit the chain. A new one of either one will not match up with the old one of the other.

--
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REAL programmers write self-modifying code.