Halfords question

In a brief moment of lucidity user scribbled:

Quoted message said:

I`ve never posted to this group before, but I`ve learned a hell of a lot about bikes by just
reading the posts. So I wonder if anyone can offer an opinion on a dispute I had yesteday with a
Halfords superstore manager. I bought a Carrera Kraken special edition last July and have returned
the bike on three occassions for repair, under warranty, for a number of faults. The most
persistent is a worrying clunk from the rear derailleur as it hits the chainstay when travelling
over any kind of bump. Going off a kerb (even slowly) produces an audible clunk. I have had to
wind tape round the chainstay to minimise the impact. The store manager told me that this is a
common fault with all mountain bikes, including bikes built by Cannondale and Trek. There was he
said nothing which could be done and I would have to learn to live with it. I`m afraid I am not
yet knowledgeable enough to challenge his statement and I was wondering if anyone can offer an
opinion. Thanks Gordon

It _is_ a common problem with lower-end componentry and some bike designs. It's a combination of
chain suck, the un-damped springs in the derailleur snapping everything back, rather than coping
with quick acting forces, and a slightly incorrectly adjusted derailleur. A re-alignment of the
derailleur can help by moving the body further away from the chain stay. BUT, you have to be
careful, it only needs to move by millimetres. Make sure you don't overdo it and move it away so
much that it's out of the chain line. If you do, then you may get chain skip (jumping off the cogs),
or worse .. 😉 I'd guess it doesn't work in all gear combinations, only some that leave the chain
pretty slack.

If everything is properly adjusted there is no way a derailleur body should connect with the chain
stay at all.

--

Completed 1581 Seti work units in 12041 hours setiathome.ssl.berkeley.edusetiathome.ssl.berkeley.eduOpen ↗

user said:

I`ve never posted to this group before, but I`ve learned a hell of a lot about bikes by just
reading the posts. So I wonder if anyone can offer an opinion on a dispute I had yesteday with a
Halfords superstore manager. I bought a Carrera Kraken special edition last July and have returned
the bike on three occassions for repair, under warranty, for a number of faults. The most
persistent is a worrying clunk from the rear derailleur as it hits the chainstay when travelling
over any kind of bump. Going off a kerb (even slowly) produces an audible clunk. I have had to
wind tape round the chainstay to minimise the impact. The store manager told me that this is a
common fault with all mountain bikes, including bikes built by Cannondale and Trek. There was he
said nothing which could be done and I would have to learn to live with it. I`m afraid I am not
yet knowledgeable enough to challenge his statement and I was wondering if anyone can offer an
opinion. Thanks Gordon

Are you sure its the rear derailleur and not the chain that's hitting? If you are in the small front
ring and small rear cog that's quite likely to happen. You can buy chainstay protectors (including
from Halfords) to protect the chainstay. Its why many mountain bikers change to the big/big
combination on rocky downhills. Try some other gear combinations that keep the chain tighter.

Tony
--
raven-family.comraven-family.comOpen ↗

"The reasonable man adapts himself to the world; the unreasonable man persists in trying to
adapt the world to himself. Therefore, all progress depends on the unreasonable man." -- George
Bernard Shaw

In a brief moment of lucidity Tony Raven scribbled:

Quoted message said:

user said:

I`ve never posted to this group before, but I`ve learned a hell of a lot about bikes by just
reading the posts. So I wonder if anyone can offer an opinion on a dispute I had yesteday with a
Halfords superstore manager. I bought a Carrera Kraken special edition last July and have
returned the bike on three occassions for repair, under warranty, for a number of faults. The
most persistent is a worrying clunk from the rear derailleur as it hits the chainstay when
travelling over any kind of bump. Going off a kerb (even slowly) produces an audible clunk. I
have had to wind tape round the chainstay to minimise the impact. The store manager told me that
this is a common fault with all mountain bikes, including bikes built by Cannondale and Trek.
There was he said nothing which could be done and I would have to learn to live with it. I`m
afraid I am not yet knowledgeable enough to challenge his statement and I was wondering if anyone
can offer an opinion. Thanks Gordon

Are you sure its the rear derailleur and not the chain that's hitting? If you are in the small
front ring and small rear cog that's quite likely to happen. You can buy chainstay protectors
(including from Halfords) to protect the chainstay. Its why many mountain bikers change to the
big/big combination on rocky downhills. Try some other gear combinations that keep the chain
tighter.

Tony

I agree, but I _have_ seen many derailleurs hitting the underside of the chainstays, exactly
as described by the P .. 😉 Generally on bikes bought from Makro, the local garage,
supermarkets etc .. 😉

--

Completed 1581 Seti work units in 12041 hours setiathome.ssl.berkeley.edusetiathome.ssl.berkeley.eduOpen ↗

Quoted message said:

Quoted message said:

Are you sure its the rear derailleur and not the chain that's hitting? If you are in the small
front ring and small rear cog that's quite likely to happen. You can buy chainstay protectors
(including from Halfords) to protect the chainstay. Its why many mountain bikers change to the
big/big combination on rocky downhills. Try some other gear combinations that keep the chain
tighter.

Tony

Its definitely the derailleur itself and it is only prevented from hitting by using a very small
range of gear combinations which stretch the chain to the greatest extent.

Quoted message said:

I agree, but I _have_ seen many derailleurs hitting the underside of the chainstays, exactly as
described by the P .. 😉 Generally on bikes bought from Makro, the local garage, supermarkets
etc .. 😉

This bike cost a whisker off £400. The components didn`t appear to be too bad for the price. The
gears are Deore, shifters Deore, 7005 Alu frame,disks are Tektro, suspension RCS, rims are Alexis.
The bike is pleasant to ride and I would be happy with it if it wern`t for the constant clunk from
the derailleur if you go over any bump bigger then a matchstick. Could the chain be too long?

Gordon

Tony Raven said:

Are you sure its the rear derailleur and not the chain that's hitting? If you are in the small
front ring and small rear cog that's quite likely to happen. You can buy chainstay protectors
(including from Halfords) to protect the chainstay. Its why many mountain bikers change to the
big/big combination on rocky downhills. Try some other gear combinations that keep the chain
tighter.

Although in general try to avoid big-big and small-small combinations of front and rear cogs -
they're bad for your chain.

Ian

--
Ian Walker Remove the yummy paste in my address to reply. Homepage: drianwalker.comdrianwalker.comOpen ↗

user said:

This bike cost a whisker off £400. The components didn`t appear to be too bad for the price. The
gears are Deore, shifters Deore, 7005 Alu frame,disks are Tektro, suspension RCS, rims are Alexis.
The bike is pleasant to ride and I would be happy with it if it wern`t for the constant clunk from
the derailleur if you go over any bump bigger then a matchstick. Could the chain be too long?

To check, put the chain in the big ring + largest cog combination and see the info and pics here:
parktool.comFAQchainlength.shtmlOpen ↗

Are you able to take any pictures and post them to the web? Might help us with the whole problem if
we see what the mech and chain look like, etc.

Sorry I don't know what the soloution is. I've never seen a mech hit a chain stay ...although that
would explain an alarming noise I've heard on some bikes!

I think you should take the bike to another bike shop to get a second opinion. Then, if there's
anything seriously wrong (ie. a part needs replacing) go back to Halfords and /demand/ (in writing
if necessary) that they sort it out. Otherwise if it's just an adjustment thing, get the other shop
to help and forget Halfords.

~PB

Pete Biggs said:

user said:

This bike cost a whisker off £400. The components didn`t appear to be too bad for the price. The
gears are Deore, shifters Deore, 7005 Alu frame,disks are Tektro, suspension RCS, rims are
Alexis. The bike is pleasant to ride and I would be happy with it if it wern`t for the constant
clunk from the derailleur if you go over any bump bigger then a matchstick. Could the chain be
too long?

To check, put the chain in the big ring + largest cog combination and see the info and pics here:
parktool.comFAQchainlength.shtmlOpen ↗

Are you able to take any pictures and post them to the web? Might help us with the whole problem if
we see what the mech and chain look like, etc.

Sorry I don't know what the soloution is. I've never seen a mech hit a chain stay ...although that
would explain an alarming noise I've heard on some bikes!

I think you should take the bike to another bike shop to get a second opinion. Then, if there's
anything seriously wrong (ie. a part needs replacing) go back to Halfords and /demand/ (in writing
if necessary) that they sort it out. Otherwise if it's just an adjustment thing, get the other shop
to help and forget Halfords.

~PB

Took your advice. Checked out the park tool site and on the basis of their advice I took a link out
of the chain. Fifteen minutes and the problem appears to have been solved!. Further benefit is
improved gear shifts. Could it have been that simple? My fingers are firmly crossed. Its taken
Halfords 9 months to fail to solve the problem. So much for the benefits of warranties. Gordon

In a brief moment of lucidity user scribbled:

Quoted message said:

Pete Biggs said:

user said:

This bike cost a whisker off £400. The components didn`t appear to be too bad for the price. The
gears are Deore, shifters Deore, 7005 Alu frame,disks are Tektro, suspension RCS, rims are
Alexis. The bike is pleasant to ride and I would be happy with it if it wern`t for the constant
clunk from the derailleur if you go over any bump bigger then a matchstick. Could the chain be
too long?

To check, put the chain in the big ring + largest cog combination and see the info and pics here:
parktool.comFAQchainlength.shtmlOpen ↗

Took your advice. Checked out the park tool site and on the basis of their advice I took a link
out of the chain. Fifteen minutes and the problem appears to have been solved!. Further benefit is
improved gear shifts. Could it have been that simple? My fingers are firmly crossed. Its taken
Halfords 9 months to fail to solve the problem. So much for the benefits of warranties. Gordon

Heheheh, a chain link removal was my next check, I generally try one thing at a time to 'fix'
problems .. I also *assumed* that the chain should have been the correct length .. though I did say
"I'd guess it doesn't work in all gear combinations, only some that leave the chain pretty slack."

Glad you got it sorted .. 😉

--

Completed 1581 Seti work units in 12041 hours setiathome.ssl.berkeley.edusetiathome.ssl.berkeley.eduOpen ↗

The Kraken is actually a very good bike for the money. It's made by Meridia (who also make GT bikes,
and a lot of Specialized bikes).

Check that the deraillure has not flicked past the stopper where the lower cage (with the jockey
wheels) attaches to the main body of the mech. I've seen numerous shimano rear deraillures suffering
from a problem where the lower cage goes past the stopper and is pushed upwards towards the
chainstay.

For those wondering WTF I am on about, it's a similar effect to when your chain jumps off into the
bottom bracket.and the deraillure is dragged forward.

user said:

Took your advice. Checked out the park tool site and on the basis of their advice I took a link
out of the chain. Fifteen minutes and the problem appears to have been solved!. Further benefit is
improved gear shifts. Could it have been that simple?

Probably :-) Let us know how it all is after another 20 miles.

Quoted message said:

My fingers are firmly crossed. Its taken Halfords 9 months to fail to solve the problem. So much
for the benefits of warranties.

~PB

Pete Biggs said:

user said:

Took your advice. Checked out the park tool site and on the basis of their advice I took a link
out of the chain. Fifteen minutes and the problem appears to have been solved!. Further benefit
is improved gear shifts. Could it have been that simple?

Probably :-) Let us know how it all is after another 20 miles.

Quoted message said:

My fingers are firmly crossed. Its taken Halfords 9 months to fail to solve the problem. So much
for the benefits of warranties.

~PB

Wiil do. Thanks for all the help and advice.Really appreciate it. Gordon