Switching Shimano Triple->Double on 5900 - chainline issues

"Jens Kurt Heycke" wrote in message . net...
"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. BRBR


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? BRBR

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? BRBR

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 . net...
"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