Rear Mech Fouling Gears- Help!

[Neal Milne]

Just changed the 11-32 tooth Deore cassette on my 2001 Sub 5 to 11-34 XT.
The rear Deore mech is now fouling the cassette when the chain is on the
biggest two cogs on the cassette. I've backed off the B-tension screw all
the way but this doesn't make any difference. I'd previously checked the
Shimano website and the Deore mech is supposed to work up to 34 tooth rear
cog. Has Shimano changed the mech between 2001 and 2003? Looks the same on
the exploded diagramme.

Will I have to buy an LX or XT mech now or maybe a longer mech hanger? Any
suggestions?

[Richard Bates]

On Sat, 19 Jul 2003 21:17:03 +0100, "Neal Milne"
> in
> wrote:

>Just changed the 11-32 tooth Deore cassette on my 2001 Sub 5 to 11-34 XT.
>The rear Deore mech is now fouling the cassette when the chain is on the
>biggest two cogs on the cassette. I've backed off the B-tension screw all
>the way but this doesn't make any difference. I'd previously checked the
>Shimano website and the Deore mech is supposed to work up to 34 tooth rear
>cog. Has Shimano changed the mech between 2001 and 2003? Looks the same on
>the exploded diagramme.
>
>Will I have to buy an LX or XT mech now or maybe a longer mech hanger? Any
>suggestions?
Are you testing the setup by having your bike upside down and turning
the pedals by hand? Gravity can cause the jockey wheels on the rear
mec to rub against the sprockets. If you turn your bike the right side
up, and actually ride it, the act of putting tension into the chain
will pull the two components aay from each other.

If, on the other hand, you are finding the problem when actually
riding, I'm sorry i cannot help!

Love and hopefullness from Rich x

--
Two cannibals eating a clown. One says to the other,
"Does this taste funny to you?"
To reply replace the obvious bit with "richard"

[Frank X]

"Neal Milne" > wrote in message
...
> Just changed the 11-32 tooth Deore cassette on my 2001 Sub 5 to 11-34 XT.
> The rear Deore mech is now fouling the cassette when the chain is on the
> biggest two cogs on the cassette. I've backed off the B-tension screw all
> the way but this doesn't make any difference. I'd previously checked the
> Shimano website and the Deore mech is supposed to work up to 34 tooth rear
> cog. Has Shimano changed the mech between 2001 and 2003? Looks the same on
> the exploded diagramme.
>
> Will I have to buy an LX or XT mech now or maybe a longer mech hanger? Any
> suggestions?
>

A shorter chain might help, if you can get away with it.

[Just zis Guy, you know?]

in article , Andy
Whitworth at wrote on
19/7/2003 9:38 pm:

> You're supposed to tighten the B-tension screw if the upper jockey wheel is
> fouling the cogs. By "backed off" do you mean tighten or loosen ?

The service instructions on shimano.com are pretty good IME.

Guy

[Jim Price]

Frank X wrote:

> "Neal Milne" > wrote in message
> ...
>
>>Just changed the 11-32 tooth Deore cassette on my 2001 Sub 5 to 11-34 XT.
>>The rear Deore mech is now fouling the cassette when the chain is on the
>>biggest two cogs on the cassette. I've backed off the B-tension screw all
>>the way but this doesn't make any difference. I'd previously checked the
>>Shimano website and the Deore mech is supposed to work up to 34 tooth rear
>>cog. Has Shimano changed the mech between 2001 and 2003? Looks the same on
>>the exploded diagramme.
>>
>>Will I have to buy an LX or XT mech now or maybe a longer mech hanger? Any
>>suggestions?
>>
>
>
> A shorter chain might help, if you can get away with it.

Actually, I would suggest an extra pair of links in the chain to make up
for the extra inch you lost going from a 32 to a 34 big sprocket at the
back, as long as you find the small-small combination doesn't cause the
derailleur to foul the sprockets. This should reduce the tension on the
chain in the large-large combination[1] back to what it was before. This
is only likely to be a working scenario if things were right before, of
course, and not being able to see your bike, its not easy to tell.

[1]which you should really avoid using, but I do it, so who am I to say!

--
Jim Price

http://www.jimprice.dsl.pipex.com

Conscientious objection is hard work in an economic war.

[Pete Biggs]

Jim Price wrote:
> Frank X wrote:
>> A shorter chain might help, if you can get away with it.
>
> Actually, I would suggest an extra pair of links in the chain to make
> up for the extra inch you lost going from a 32 to a 34 big sprocket
> at the back

Frank's right. A shorter chain will pull the mech further away from the
sprocket - the best trick in the book for solving this problem. Only
trouble is, the chain does need to be long enough for the big-big*. If
lucky, the chain would have been longer than necessary in the first place
(they usually are). But if not, shortening might not be possible and a
link may indeed have to be added (then alternative solutions will have to
be found).

And forget small-small. Doesn't matter if chain drags in that because it
shouldn't be used either. Again, as long as nothing will break, it
doesn't matter, IMO.

* This crossed-over gear shouldn't normally be used but chain still needs
to be long enough for it in case it's accidentally selected. As short as
possible for this gear without risk of breaking anything will do - doesn't
matter if performance in it is otherwise rubbish.

~PB

[Pete Biggs]

Neal Milne wrote:
> Just changed the 11-32 tooth Deore cassette on my 2001 Sub 5 to 11-34
> XT. The rear Deore mech is now fouling the cassette when the chain is
> on the biggest two cogs on the cassette.

On which chainring?

I assumed you meant inner for my first reply.

~PB

[Pete Biggs]

Jim Price wrote:

>> Frank's right. A shorter chain will pull the mech further away from
>> the sprocket
>
> Not once the cage of the derailleur nears its full travel

It only nears its full travel in the big-big. It will be nowhere near
full stretch in the small-big, regardless of cassette changes. Unless the
chain is absurdly short by a great number of links, removing links will
ALWAYS increase clearance between upper jockey wheel and large sprockets
when in the inner ring and large sprockets.

~PB

[Garry Broad]

On Sat, 19 Jul 2003 21:17:03 +0100, "Neal Milne"
> wrote:

>Just changed the 11-32 tooth Deore cassette on my 2001 Sub 5 to 11-34 XT.
>The rear Deore mech is now fouling the cassette when the chain is on the
>biggest two cogs on the cassette. I've backed off the B-tension screw all
>the way but this doesn't make any difference. I'd previously checked the
>Shimano website and the Deore mech is supposed to work up to 34 tooth rear
>cog. Has Shimano changed the mech between 2001 and 2003? Looks the same on
>the exploded diagramme.
>
>Will I have to buy an LX or XT mech now or maybe a longer mech hanger? Any
>suggestions?

I had this exact problem a while a go, but in a slghtly different
context - I put a Deore 9sp 30-11 cassette (mountain bike casstte of
course), on a Cannondale road bike! It worked fine until I got to
big-big, then I had this ugly noise from the derailleur (shimano 105)
knocking against the teeth of the casstte. Tried everything: longer
chain, shorter chain, different chain, adjusting the derailleur. In
the end I just accepted that I had a compatibility problem. Switched
the casstte to a 9 sp 11-25 and away we go, sorted. I could have
changed the derailleur of course, but that seemed kind of crazy really
seeing as though the 105 is supposed to be for this particular bike.

A different derailleur or cassette 'might' be your only way out here.

Garry

[Peter B]

"Neal Milne" > wrote in message
...
> Just changed the 11-32 tooth Deore cassette on my 2001 Sub 5 to 11-34 XT.
> The rear Deore mech is now fouling the cassette when the chain is on the
> biggest two cogs on the cassette.

I've recently experienced a similar problem on my mtb after 3.5 years even
though the mech is original and the cassette the same size as the previous
ones, 11-32.
I shortened the chain even though it had been no longe than the original and
tried the B screw. This cured things temporarily but last weekend during a
pre-ride check I found the mech had seized on the hanger pivot.
So maybe it had been tight but movable before.
It was a simple job to strip, clean and re-lube the pivot to restore it to
its former glory.

Just a thought.

(Changing to an LX or XT will make no difference, they are rated for max 34
the same as Deore).
http://www.shimano-europe.com/cycling/phpimages/product/exp_view/RD-M510.pdf

Pete

[Just zis Guy, you know?]

in article , Pete Biggs at
wrote on 19/7/2003 11:06 pm:

> Frank's right. A shorter chain will pull the mech further away from the
> sprocket - the best trick in the book for solving this problem.

I would adjust the B screw before shortening the chain, especially as the
biggest sprocket is now larger (so more chain length may be required). The
Park site and shimano.com both have details on how to adjust the B screw,
and it's not very difficult.

Guy

[Garry Broad]

opps, sorry, hadn't read your original post as well as I might have
done...seems your rear mech should work.

beer-blury eyes i guess!

Garry

>On Sat, 19 Jul 2003 21:17:03 +0100, "Neal Milne"
> wrote:
>
>>Just changed the 11-32 tooth Deore cassette on my 2001 Sub 5 to 11-34 XT.
>>The rear Deore mech is now fouling the cassette when the chain is on the
>>biggest two cogs on the cassette. I've backed off the B-tension screw all
>>the way but this doesn't make any difference. I'd previously checked the
>>Shimano website and the Deore mech is supposed to work up to 34 tooth rear
>>cog. Has Shimano changed the mech between 2001 and 2003? Looks the same on
>>the exploded diagramme.
>>
>>Will I have to buy an LX or XT mech now or maybe a longer mech hanger? Any
>>suggestions?
>
>I had this exact problem a while a go, but in a slghtly different
>context - I put a Deore 9sp 30-11 cassette (mountain bike casstte of
>course), on a Cannondale road bike! It worked fine until I got to
>big-big, then I had this ugly noise from the derailleur (shimano 105)
>knocking against the teeth of the casstte. Tried everything: longer
>chain, shorter chain, different chain, adjusting the derailleur. In
>the end I just accepted that I had a compatibility problem. Switched
>the casstte to a 9 sp 11-25 and away we go, sorted. I could have
>changed the derailleur of course, but that seemed kind of crazy really
>seeing as though the 105 is supposed to be for this particular bike.
>
>A different derailleur or cassette 'might' be your only way out here.
>
>Garry
>

[Pete Biggs]

Neal Milne wrote:
> The Shimano website seems to clearly state that the b-tension screw
> should be screwed out to drop the mech top jockey wheel.

I'm not sure what you mean by "out" but the screw needs to be turned
clockwise, no doubt about it. I would call that "in"! It's unusual to
have the problem on next sprocket and ring, so I suspect the b-screw is
all wrong.

In fact, another trick I forgot to mention is to replace the screw with a
longer one. (That's a nasty bodge though and shouldn't normally be
needed).

~PB

[Neal Milne]

I've tried the screw all the way in and all the way out and it doesn't seem
to make much diffference.

The mech needs to move backwards to clear the gears this means that it needs
to go in the opposite direction to the b-spring tension. Therefore screwing
the b-screw out taking tension off the b-spring should be the way to go a-la
the Shimano website.

[Jim Price]

Pete Biggs wrote:

> Jim Price wrote:
>
>
>>>Frank's right. A shorter chain will pull the mech further away from
>>>the sprocket
>>
>>Not once the cage of the derailleur nears its full travel
>
>
> It only nears its full travel in the big-big. It will be nowhere near
> full stretch in the small-big, regardless of cassette changes.

Read the original post. The problem is specifially stated as being in
the big-big combination. Nothing is stated about small-big.

--
Jim Price

http://www.jimprice.dsl.pipex.com

Conscientious objection is hard work in an economic war.

[Pete Biggs]

Jim Price wrote:

/snip snip snip

Ok fine ...I think! :-) Sorry for the misunderstandings.

BTW, Neal has now said that there are problems when on the small ring -
which I thought was most likely from the start.

~PB

[Just zis Guy, you know?]

in article , Pete Biggs at
wrote on 20/7/2003 1:25 pm:

> Screwing in the b-tension screw (clockwise) forces the mech body back,
> etc. I've done this many times and can assure you that this is what's
> required.

ISTR that the details are slightly different for various mechs. I have used
Acera, Deore, LX and XTR, and the XTR (from memory) had a different
procedure for setup and adjustment from other Deore series - but the service
instructions on the Shimano website are straightforward (if in very small
print).

I have switched between 25T and 32T max sprocket on my Stinger and my tourer
with no problems (I switch cassettes a few times a year since I use
wide-range ones for century rides or long hilly routes), and the B screw is
definitely crucial to proper operation. I can't remember whether you need
to screw in or out, but I can remember that you have to follow the
instructions and not rely on judgement or what looks right. I tried working
it out from engineering principles and I tried what looked right, but only
following the instructions actually resulted in a consistently clean shift
and quiet operation.

It is best if you clean the chain thoroughly first, I should have mentioned
that, and make sure the parallelogram pivots and the main mech pivot are
free and clean.

Guy

[Garry Broad]

On Sun, 20 Jul 2003 13:43:55 +0100, "Mark South"
> wrote:

>"Garry Broad" > wrote
>> I had this exact problem a while a go, but in a slightly different
>> context - I put a Deore 9sp 30-11 cassette (mountain bike cassette of
>> course), on a Cannondale road bike! It worked fine until I got to
>> big-big, then I had this ugly noise from the derailleur (shimano 105)
>> knocking against the teeth of the cassette. Tried everything: longer
>> chain, shorter chain, different chain, adjusting the derailleur. In
>> the end I just accepted that I had a compatibility problem. Switched
>> the cassette to a 9 sp 11-25 and away we go, sorted. I could have
>> changed the derailleur of course, but that seemed kind of crazy really
>> seeing as though the 105 is supposed to be for this particular bike.
>
>Is it correct that Shimano road mechs have a max sprocket rating of 27
>teeth?

ahem..<clearing thoat>...err, I think so yes, but I didn't know what I
was doing :-)
This was a Cannondale Caad4 bike I bought without wheels, so I had to
provide wheels and a casstte to get it rideble. It has a 9sp STI
system, so I just bought a 9sp 11-32 cassette for the wide gear range
possibilities. This is when I ran into problems with the big-big
combination. So I just swaped the casstte with something that should
have been on there originally..and all was well.

This is how we learn I guess :-)

Garry

[Just zis Guy, you know?]

in article , Neal Milne at
wrote on 20/7/2003 12:11 pm:

> I've tried the screw all the way in and all the way out and it doesn't seem
> to make much diffference.

I suggest you go back to first principles. Take the mech off and clean it
thoroughly, including the jockey wheels (I like the Tackx wheels myself),
clean the chain as well. Take the inner out of the gear cable and make sure
it is clean and free of grit. You could lubricate it by wiping with a
slightly oily cloth (not everybody agrees with this).

Lubricate all the pivots, and then put the mech, cable and chain back on.
Check that the chain is long enough to do big/big (the mech should cope with
the full range even if the chain path can't, I manage on my recumbent which
has no "forbidden ratios" because the chain path is so long). You may well
need to add a link when going up to a cassette this big. Check that in
small/small the chain is not rubbing on itself as it comes round the mech
(this will change as you adjust the B screw, so don't get too hung up about
it just yet).

Now slacken the B screw off and follow the service instructions for your
particular mech to get the B screw right. Hysteresis in the mech springs is
your enemy here, I find that running down the cogs and back up again after
each turn of the B screw can help a bit.

Adjusting the B screw on a mech which has seen a few miles can be a bit of a
faff, and beware of mangling the screw head, but it is generally
satisfactory if you follow the Cunning Plan.

Guy

[Mark South]

"Garry Broad" > wrote in message
...
> On Sun, 20 Jul 2003 13:43:55 +0100, "Mark South"
> > wrote:
>
> >"Garry Broad" > wrote
> >> I had this exact problem a while a go, but in a slightly different
> >> context - I put a Deore 9sp 30-11 cassette (mountain bike cassette
of
> >> course), on a Cannondale road bike! It worked fine until I got to
> >> big-big, then I had this ugly noise from the derailleur (shimano
105)
> >> knocking against the teeth of the cassette. Tried everything:
longer
> >> chain, shorter chain, different chain, adjusting the derailleur. In
> >> the end I just accepted that I had a compatibility problem.
Switched
> >> the cassette to a 9 sp 11-25 and away we go, sorted. I could have
> >> changed the derailleur of course, but that seemed kind of crazy
really
> >> seeing as though the 105 is supposed to be for this particular
bike.
> >
> >Is it correct that Shimano road mechs have a max sprocket rating of
27
> >teeth?
>
> ahem..<clearing thoat>...err, I think so yes, but I didn't know what I
> was doing :-)

Good enough explanation :-)

> This was a Cannondale Caad4 bike I bought without wheels, so I had to
> provide wheels and a casstte to get it ridable. It has a 9sp STI
> system, so I just bought a 9sp 11-32 cassette for the wide gear range
> possibilities. This is when I ran into problems with the big-big
> combination. So I just swapped the cassette with something that should
> have been on there originally..and all was well.

It's great that it's working for you now. For next time, remember that
it's normally stamped on the mech cage somewhere!

> This is how we learn I guess :-)

It's also how we acquire those huge piles of potentially useful bits
that don't quite fit any purpose that we need fulfilled right now, but
can't be thrown out in case they one day suddenly become *just* the
thing we need.

Trust me, I know what I'm talking about on this one :-)

--
Mark South: Citizen of the World, Denizen of the Net
"I wonder why so many Finnish traditions are related with booze?"
- Juha Sakkinen

[Peter B]

"Mark South" > wrote in message
...

> Is it correct that Shimano road mechs have a max sprocket rating of 27
> teeth?

Yes.

Pete

[Peter B]

"Garry Broad" > wrote in message
...
> I had this exact problem a while a go, but in a slghtly different
> context - I put a Deore 9sp 30-11 cassette (mountain bike casstte of
> course), on a Cannondale road bike! It worked fine until I got to
> big-big, then I had this ugly noise from the derailleur (shimano 105)
> knocking against the teeth of the casstte.

> A different derailleur or cassette 'might' be your only way out here.

A long cage rear mech is capable of taking up more slack chain than a short
cage thus increasing the "capacity" of the drive train, that is the
difference in the number of teeth between the smallest and biggest cogs and
rings <1>.
The greater the range of teeth the more the amount of spare chain there will
be flapping about when on the smallest chainring and smallest sprocket
whilst allowing sufficient chain to be available for use on the biggest
chainring and biggest sprocket.
Good practice is to avoid these extremes by at least 2 sprockets at either
end of the range, however accidental selection must be allowed for.

Most double clanger "racing" bikes have a short cage and most mtbs have a
long cage to suit their close ratios and wide ratios respectively. Other
bikes may have either.

MTB rear mechs have a longer parralelogram body than road mechs to increase
the distance between the main pivot and the cage pivot to help keep the
upper jockey wheel away from the bigger diameter sprockets generally used.

This is why 105 and Ultegras are rated for a maximum sprocket size of 27
whereas Deore/LX/XT are rated for a max sprocket size of 34.

You might get a road mech to work with a cog >27 teeth but who wants to dick
around trying to make one perform adequately at best when you can buy the
proper job for afew quid and have the whole thing work spot-on without
really trying?

<1> http://www.shimano-europe.com/cycling/ gives info on mech capacity along
with much else.

Pete

[Neal Milne]

I'll give the mech a clean up and start agian. I'm pretty sure I've got the
chain length right. Its working in big-big and doesn't rub on the mech when
on the small chainring until over halfway down the block.

[Dave Larrington]

Mark South wrote:

> Is it correct that Shimano road mechs have a max sprocket rating of 27
> teeth?

That's what Shimano say, however they /will/ work with a 28.

Dave Larrington - http://www.legslarry.beerdrinkers.co.uk/
================================================== =========
Editor - British Human Power Club Newsletter
http://www.bhpc.org.uk/
================================================== =========

[Robert Taylor]

Neal Milne wrote:
> Just changed the 11-32 tooth Deore cassette on my 2001 Sub 5 to 11-34
> XT. The rear Deore mech is now fouling the cassette when the chain is on
> the biggest two cogs on the cassette. I've backed off the B-tension
> screw all the way but this doesn't make any difference. I'd previously
> checked the Shimano website and the Deore mech is supposed to work up to
> 34 tooth rear cog. Has Shimano changed the mech between 2001 and 2003?
> Looks the same on the exploded diagramme.
> Will I have to buy an LX or XT mech now or maybe a longer mech hanger?
> Any suggestions?

I had this same sort of problem and I solved it by replacing the 11
tooth top jockey pulley with a 10 tooth one from a Shimano 8 speed rear
mech (the 10 tooth pulleys from pre 8 speed mechs are thicker and don't
work). Alternatively one could buy a set of 10 tooth aftermarket sealed
cartridge jockey pulleys and replace the 11 tooth top pulley with one of
them. Most of these aftermarket pulleys are supposed to float back and
forth like the standard Shimano pulleys but also end up turning on the
bushing rather than the cartridge bearing. The bushing and washers
supplied for use with the bottom pulley can be used at the top position
resulting in a pulley which rotates on it's sealed bearing but which
does not float. For me this approach worked at least as well as having
the pulley float back and forth. I never sid understand what the
floating was supposed to accomplish. It appeared on Shimano mechs before
the indexed shift era and may just be a marketing ploy from long ago.

It also helps to shorten the chain as much as possible while still
permitting the Big/Big combination.

Bob Taylor




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