chain slippage on biggest rear gears

Leon Horsnell said:

When I ride my mtn bike the chain slips when it is on the biggest front
cog and either the biggest or second biggest back cog. When the chain is on
the second biggest front cog and the two largest back cogs it does not slip
as much.
I am new to these things and have bought the bike second hand but it
would be interesting to know what this is a symptom of, ie is my back hub or
front hub going etc

I'm somewhat of a beginner here too, but it could be stretched chain,
worn sprockets or maladjusted shifting mechanism. Aside from taking in
for an inspection or buying a book on how - to, I can't think of any way
to check. If you search the Web, you'll find methods to check each item.
Checking the chain and the sprockets is fairly easy, IMO.

I had a good look at it since i wrote the email, i had had a look before but
only at the cogs. The chain seems to be worn. a few links maybe 5 have lost
there little movable ring on them.
could that be the problem combined with in appropriate gear choice
thanks
leon
"Leon Horsnell" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

When I ride my mtn bike the chain slips when it is on the biggest
front cog and either the biggest or second biggest back cog. When the
chain is on the second biggest front cog and the two largest back cogs it
does not slip as much.
I am new to these things and have bought the bike second hand but it
would be interesting to know what this is a symptom of, ie is my back hub
or front hub going etc
thanks
leon

Leon Horsnell said:

When I ride my mtn bike the chain slips when it is on the biggest front
cog and either the biggest or second biggest back cog. When the chain is on
the second biggest front cog and the two largest back cogs it does not slip
as much.
I am new to these things and have bought the bike second hand but it
would be interesting to know what this is a symptom of,

It is a symptom of the cassette being worn out. You really notice it when
you replace the chain.

Replace the cassette.

--

David L. Johnson

__o | It is a scientifically proven fact that a mid life crisis can
_`\(,_ | only be cured by something racy and Italian. Bianchis and
(_)/ (_) | Colnagos are a lot cheaper than Maserattis and Ferraris. --
Glenn Davies

thanks for the advice i'll get it done
leon
"David L. Johnson" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Leon Horsnell said:

When I ride my mtn bike the chain slips when it is on the biggest
front
cog and either the biggest or second biggest back cog. When the chain is
on
the second biggest front cog and the two largest back cogs it does not
slip
as much.
I am new to these things and have bought the bike second hand but
it
would be interesting to know what this is a symptom of,

It is a symptom of the cassette being worn out. You really notice it when
you replace the chain.

Replace the cassette.

--

David L. Johnson

__o | It is a scientifically proven fact that a mid life crisis can
_`\(,_ | only be cured by something racy and Italian. Bianchis and
(_)/ (_) | Colnagos are a lot cheaper than Maserattis and Ferraris. --
Glenn Davies

Leon Horsnell said:

When I ride my mtn bike the chain slips when it is on the biggest
front cog and either the biggest or second biggest back cog. When
the chain is on the second biggest front cog and the two largest
back cogs it does not slip as much. I am new to these things and
have bought the bike second hand but it would be interesting to know
what this is a symptom of, ie is my back hub or front hub going etc.

You may have x different gear combinations but there are a few that
generally don't work well and should be avoided by using other
combinations that produce the same ratio. These are the maximum
cross-over gears, particularly the ones you mention. Running the
chain as a steep side angle eats away at the aluminum chainrings as
the chain enters under load. It can also cause chain skip as you
describe. Use the inner chainwheels for the largest rear sprockets.
If they don't skip under load in that mode, then you have the answer.

Similarly the inner chainwheel doesn't like crossing over to the
smallest sprocket in the rear and the chain may even drag on the
adjacent larger chainwheel in that mode. See whether that works and
let us know.

Jobst Brandt

http://www.sheldonbrown.com/derailer-adjustment.html
--
DTW .../\.../\.../\...

Leon Horsnell said:

When I ride my mtn bike the chain slips when it is on the biggest front
cog and either the biggest or second biggest back cog. When the chain is on
the second biggest front cog and the two largest back cogs it does not slip
as much.
I am new to these things and have bought the bike second hand but it
would be interesting to know what this is a symptom of, ie is my back hub or
front hub going etc
thanks
leon

Check the chain and cog wear article at Sheldon Brown's web site:
sheldonbrown.comchains.htmlOpen ↗