I decided to convert my Trek 5900 from a Triple to a Double.
So I got a Double crankset, double front & rear derailleurs,
and an Ultegra double bottom bracket (109.5).

After setting it up I've found that the 39-11 combination
causes the chain to rub on the inside of the big chainring.
I assume this is a chainline issue. Do I need to go back to
using a Ultegra triple BB (118.5) even though the crankset
is a double? Can I simply avoid this combination and
be OK, or I'm I going to always have extra drivetrain
friction because of a poor chainline?



thanks in advance,

Jens

"Jens Kurt Heycke" > wrote in message
et...
> I decided to convert my Trek 5900 from a Triple to a Double.
> So I got a Double crankset, double front & rear derailleurs,
> and an Ultegra double bottom bracket (109.5).
>
> After setting it up I've found that the 39-11 combination
> causes the chain to rub on the inside of the big chainring.
> I assume this is a chainline issue. Do I need to go back to
> using a Ultegra triple BB (118.5) even though the crankset
> is a double? Can I simply avoid this combination and
> be OK, or I'm I going to always have extra drivetrain
> friction because of a poor chainline?


The small/small or big/big combos are a BAD thing. If you avoid these
gears, you'll be OK.

The 39/53 combo sees a bit of chain rubbing on the outer ring from about the
third cog from smallest down. If you MUST ride in these gears, there's
usually a trim click in the left lever.

If you go to either Sheldon's site, or www.fixedgearfever.com you can find a
gear inch or progression chart to show you where the overlap is. That way,
you avoid funky chainlines while maintaining the same gear.

Mike

Mike S. <mikeshaw2@coxDOTnet> wrote:

> The small/small or big/big combos are a BAD thing. If you avoid these
> gears, you'll be OK.

> The 39/53 combo sees a bit of chain rubbing on the outer ring from about the
> third cog from smallest down. If you MUST ride in these gears, there's
> usually a trim click in the left lever.

The trim click won't help the situation of the chain rubbing the big ring
when in the 39/11. That rubbing is normal and, that combination should be
avoided. The trim keeps the chain from rubbing on the FD.

Art Harris

"Harris" > wrote in message
...
> Mike S. <mikeshaw2@coxDOTnet> wrote:
>
> > The small/small or big/big combos are a BAD thing. If you avoid these
> > gears, you'll be OK.
>
> > The 39/53 combo sees a bit of chain rubbing on the outer ring from about
the
> > third cog from smallest down. If you MUST ride in these gears, there's
> > usually a trim click in the left lever.
>
> The trim click won't help the situation of the chain rubbing the big ring
> when in the 39/11. That rubbing is normal and, that combination should be
> avoided. The trim keeps the chain from rubbing on the FD.
>
Interesting, do you really need an 11t?

Jens: You *do* have correct chainline, and that's why it's scraping.
You're running in as heavily crossed-over gear combo as you can get, with
the chain describing a diagonal line between the small front and small rear
cogs. Trimming the front derailleur probably won't help, because the chain
is most likely scraping against the large chainring as it heads towards the
rear of the bike.

If you move the chainline out (using a longer spindle), you're going to have
a very noisy drivetrain when in your larger chainring and, worse yet, you'll
find the chain falling off the inside of the crank when you shift from the
large to the small front chainring. That can be serious bad news and wreck
your day if it happens at the wrong time!

More than likely you'll find that 11/39 combo is close to something
available when you're on your 53t.

--Mike--
Chain Reaction Bicycles
www.ChainReaction.com

"Jens Kurt Heycke" > wrote in message
et...
> I decided to convert my Trek 5900 from a Triple to a Double.
> So I got a Double crankset, double front & rear derailleurs,
> and an Ultegra double bottom bracket (109.5).
>
> After setting it up I've found that the 39-11 combination
> causes the chain to rub on the inside of the big chainring.
> I assume this is a chainline issue. Do I need to go back to
> using a Ultegra triple BB (118.5) even though the crankset
> is a double? Can I simply avoid this combination and
> be OK, or I'm I going to always have extra drivetrain
> friction because of a poor chainline?
>
>
>
> thanks in advance,
>
> Jens
>
>
>

In article et>,
says...
>
> "Harris" > wrote in message
> ...
> > Mike S. <mikeshaw2@coxDOTnet> wrote:
> >
> > > The small/small or big/big combos are a BAD thing. If you avoid these
> > > gears, you'll be OK.
> >
> > > The 39/53 combo sees a bit of chain rubbing on the outer ring from about
> the
> > > third cog from smallest down. If you MUST ride in these gears, there's
> > > usually a trim click in the left lever.
> >
> > The trim click won't help the situation of the chain rubbing the big ring
> > when in the 39/11. That rubbing is normal and, that combination should be
> > avoided. The trim keeps the chain from rubbing on the FD.
> >
> Interesting, do you really need an 11t?

Yes. I use my 52x11 a lot more than I do my 30x32 granny. Neither
one is used much, but the 30x32 is "practically never", while the
52x11 is "occasionally".

--
Dave Kerber
Fight spam: remove the ns_ from the return address before replying!

REAL programmers write self-modifying code.

Thanks Mike! I was curious about this because the symptoms of
extreme combinations with the triple were much different, i.e. the rubbing
was on the cassette, not the chainring. I was concerned
it might be symptomatic of a more general drivetrain alignment
problem.

I never use the extreme combinations in actual pedaling, but they're
useful for quick chain length checking.


thanks again,

Jens


"Mike Jacoubowsky/Chain Reaction Bicycles" > wrote
in message .. .
> Jens: You *do* have correct chainline, and that's why it's scraping.
> You're running in as heavily crossed-over gear combo as you can get, with
> the chain describing a diagonal line between the small front and small
rear
> cogs. Trimming the front derailleur probably won't help, because the
chain
> is most likely scraping against the large chainring as it heads towards
the
> rear of the bike.
>
> If you move the chainline out (using a longer spindle), you're going to
have
> a very noisy drivetrain when in your larger chainring and, worse yet,
you'll
> find the chain falling off the inside of the crank when you shift from the
> large to the small front chainring. That can be serious bad news and
wreck
> your day if it happens at the wrong time!
>
> More than likely you'll find that 11/39 combo is close to something
> available when you're on your 53t.
>
> --Mike--
> Chain Reaction Bicycles
> www.ChainReaction.com
>
> "Jens Kurt Heycke" > wrote in message
> et...
> > I decided to convert my Trek 5900 from a Triple to a Double.
> > So I got a Double crankset, double front & rear derailleurs,
> > and an Ultegra double bottom bracket (109.5).
> >
> > After setting it up I've found that the 39-11 combination
> > causes the chain to rub on the inside of the big chainring.
> > I assume this is a chainline issue. Do I need to go back to
> > using a Ultegra triple BB (118.5) even though the crankset
> > is a double? Can I simply avoid this combination and
> > be OK, or I'm I going to always have extra drivetrain
> > friction because of a poor chainline?
> >
> >
> >
> > thanks in advance,
> >
> > Jens
> >
> >
> >
>
>

> > > The small/small or big/big combos are a BAD thing. If you avoid these
> > > gears, you'll be OK.
> >
> > > The 39/53 combo sees a bit of chain rubbing on the outer ring from
about
> the
> > > third cog from smallest down. If you MUST ride in these gears,
there's
> > > usually a trim click in the left lever.
> >
> > The trim click won't help the situation of the chain rubbing the big
ring
> > when in the 39/11. That rubbing is normal and, that combination should
be
> > avoided. The trim keeps the chain from rubbing on the FD.
> >
> Interesting, do you really need an 11t?
>
Its going to rub a first position 12t or 13t too, so what difference does it
make?

Mike

"Jens Kurt Heycke" > wrote in message
et...
>
> Thanks Mike! I was curious about this because the symptoms of
> extreme combinations with the triple were much different, i.e. the rubbing
> was on the cassette, not the chainring. I was concerned
> it might be symptomatic of a more general drivetrain alignment
> problem.
>
> I never use the extreme combinations in actual pedaling, but they're
> useful for quick chain length checking.
>
That the are...

Mike




> thanks again,
>
> Jens
>
>
> "Mike Jacoubowsky/Chain Reaction Bicycles" > wrote
> in message .. .
> > Jens: You *do* have correct chainline, and that's why it's scraping.
> > You're running in as heavily crossed-over gear combo as you can get,
with
> > the chain describing a diagonal line between the small front and small
> rear
> > cogs. Trimming the front derailleur probably won't help, because the
> chain
> > is most likely scraping against the large chainring as it heads towards
> the
> > rear of the bike.
> >
> > If you move the chainline out (using a longer spindle), you're going to
> have
> > a very noisy drivetrain when in your larger chainring and, worse yet,
> you'll
> > find the chain falling off the inside of the crank when you shift from
the
> > large to the small front chainring. That can be serious bad news and
> wreck
> > your day if it happens at the wrong time!
> >
> > More than likely you'll find that 11/39 combo is close to something
> > available when you're on your 53t.
> >
> > --Mike--
> > Chain Reaction Bicycles
> > www.ChainReaction.com
> >
> > "Jens Kurt Heycke" > wrote in message
> > et...
> > > I decided to convert my Trek 5900 from a Triple to a Double.
> > > So I got a Double crankset, double front & rear derailleurs,
> > > and an Ultegra double bottom bracket (109.5).
> > >
> > > After setting it up I've found that the 39-11 combination
> > > causes the chain to rub on the inside of the big chainring.
> > > I assume this is a chainline issue. Do I need to go back to
> > > using a Ultegra triple BB (118.5) even though the crankset
> > > is a double? Can I simply avoid this combination and
> > > be OK, or I'm I going to always have extra drivetrain
> > > friction because of a poor chainline?
> > >
> > >
> > >
> > > thanks in advance,
> > >
> > > Jens
> > >
> > >
> > >
> >
> >
>
>

"bfd" > wrote in message
ink.net...
>
> "Harris" > wrote in message
> ...
> > Mike S. <mikeshaw2@coxDOTnet> wrote:
> >
> > > The small/small or big/big combos are a BAD thing. If you avoid these
> > > gears, you'll be OK.
> >
> > > The 39/53 combo sees a bit of chain rubbing on the outer ring from
about
> the
> > > third cog from smallest down. If you MUST ride in these gears,
there's
> > > usually a trim click in the left lever.
> >
> > The trim click won't help the situation of the chain rubbing the big
ring
> > when in the 39/11. That rubbing is normal and, that combination should
be
> > avoided. The trim keeps the chain from rubbing on the FD.
> >
> Interesting, do you really need an 11t?
>
>

Yes. Riding buddies call me "Torque-mada"

I didn't expect the Spanish Inquisition. ;-)

--Jens

"Jens Kurt Heycke" > wrote in message >...
> "bfd" > wrote in message
> ink.net...
> >
> > "Harris" > wrote in message
> > ...
> > > Mike S. <mikeshaw2@coxDOTnet> wrote:
> > >
> > > > The small/small or big/big combos are a BAD thing. If you avoid these
> > > > gears, you'll be OK.
>
> > > > The 39/53 combo sees a bit of chain rubbing on the outer ring from
> about
> the
> > > > third cog from smallest down. If you MUST ride in these gears,
> there's
> > > > usually a trim click in the left lever.
> > >
> > > The trim click won't help the situation of the chain rubbing the big
> ring
> > > when in the 39/11. That rubbing is normal and, that combination should
> be
> > > avoided. The trim keeps the chain from rubbing on the FD.
> > >
> > Interesting, do you really need an 11t?
> >
> >
>
> Yes. Riding buddies call me "Torque-mada"
>
> I didn't expect the Spanish Inquisition. ;-)
>
> --Jens

Dear Jens,

Like you, I run a stately 53 x 11. Pay no attention
to those hamsters frantically scampering around
and spinning wildly.

Carl Fogel

"Carl Fogel" > wrote in message
om...
> "Jens Kurt Heycke" > wrote in message
news:<86bvb.6085> > > Interesting, do you
> >
> > Yes. Riding buddies call me "Torque-mada"
> >
> > I didn't expect the Spanish Inquisition. ;-)
> >
> > --Jens
>
> Dear Jens,
>
> Like you, I run a stately 53 x 11. Pay no attention
> to those hamsters frantically scampering around
> and spinning wildly.
>
> Carl Fogel

You only get so many pedal spins in a lifetime... then you're finished
So you need to be economical with them.

Incidentally, I've had a problem with the Dura-ace 11-23 cassettes.
The 3rd and 4th smallest gears seem to have a very slight grind to them.
It seems to happen once per revolution like a bent tooth or something.
I first noticed it when I started using it on the trainer indoor. I tried
a brand new chain and a brand new cassette and had the same
problem. I even tried a different wheel in case it was a hub or axle
issue, but the grind was still there.

No amount of tweaking barrel adjusters makes it go away.
This does not happen with the DA 12-25 & 12-27 cassettes.
Have you noticed this? I'm wondering if Shimano hasn't made some defective
cassetes.


-j

Jens-<< I decided to convert my Trek 5900 from a Triple to a Double.
So I got a Double crankset, double front & rear derailleurs,
and an Ultegra double bottom bracket (109.5).

After setting it up I've found that the 39-11 combination
causes the chain to rub on the inside of the big chainring.
I assume this is a chainline issue. >><BR><BR>


IT IS NOT A PROBLEM...with 9 cogs and little doodads on the big ring, you will
experience this when in small ring and smallish cogs. It is NOT a problem that
needs any solution othert than not riding cross chained.

Jens-
<< Do I need to go back to
using a Ultegra triple BB (118.5) even though the crankset
is a double? >><BR><BR>

Ya do and your chainline will be awful...front der may not work at all, or at
least poorly.

Jens-
<< Can I simply avoid this combination and
be OK, or I'm I going to always have extra drivetrain
friction because of a poor chainline? >><BR><BR>

bing, bing, bing, we have a winner. Check your chainline , a line from the
center of the crank to the 5th cog up, it will be an amazing straight line,
parallel to the top tube.

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

"Jens Kurt Heycke" > wrote in message >...
> "Carl Fogel" > wrote in message
> om...
> > "Jens Kurt Heycke" > wrote in message
> news:<86bvb.6085> > > Interesting, do you
> > >
> > > Yes. Riding buddies call me "Torque-mada"
> > >
> > > I didn't expect the Spanish Inquisition. ;-)
> > >
> > > --Jens
> >
> > Dear Jens,
> >
> > Like you, I run a stately 53 x 11. Pay no attention
> > to those hamsters frantically scampering around
> > and spinning wildly.
> >
> > Carl Fogel
>
> You only get so many pedal spins in a lifetime... then you're finished
> So you need to be economical with them.
>
> Incidentally, I've had a problem with the Dura-ace 11-23 cassettes.
> The 3rd and 4th smallest gears seem to have a very slight grind to them.
> It seems to happen once per revolution like a bent tooth or something.
> I first noticed it when I started using it on the trainer indoor. I tried
> a brand new chain and a brand new cassette and had the same
> problem. I even tried a different wheel in case it was a hub or axle
> issue, but the grind was still there.
>
> No amount of tweaking barrel adjusters makes it go away.
> This does not happen with the DA 12-25 & 12-27 cassettes.
> Have you noticed this? I'm wondering if Shimano hasn't made some defective
> cassetes.
>
>
> -j


Dear Jens,

No, I haven't noticed any odd gear-tooth
problems, but my opinion on the matter is
probably worthless. I use ancient friction
shifters and only a few gears. Even worse,
they're 7-speed cassettes, of which I have
a fair number of spares.

Probably 80% of my riding is done in 53 x 11.
Most of the rest is done in 39 x whatever the
second largest rear cog is, sometimes the third.
My daily 15-mile ride is, from what I gather,
peculiar, but extremely pleasant.

I do notice, however, that Shimano rear cogs
have various indents, scallops, and minor
carvings intended to help the chain shift.
Possibly you have some kind of chain mis-match?
I don't know enough about this to say anything
helpful, but luckily there are an awful lot of
remarkably knowledgeable and helpful fellows
just aching to see questions like this.

Good luck,

Carl Fogel