Eccentric BB

Phil Holman said:

The chain on my newly acquired Canondale tandem is a tad on the slack side. There is a single bolt
that goes through the eccentric part that is easily removed. Now what? I don't want to reef on it
until I know how the mechanism works. Any help appreciated.

Just loosen the bolt a bit, insert a pin or hook spanner (depending on the design of your
eccentric), and turn the eccentric until you get the desired chain tension. Don't make it TOO
tight - I have had the best luck when I can get about 1/2" (1.2cm) of movement out of the chain
at midspan.

Mark Hickey Habanero Cycles habcycles.comhabcycles.comOpen ↗ Home of the $695 ti frame

"Mark Hickey" <[email hidden]> wrote in message
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Quoted message said:

Phil Holman said:

The chain on my newly acquired Canondale tandem is a tad on the slack side. There is a single
bolt that goes through the eccentric part

that

Quoted message said:

Quoted message said:

is easily removed. Now what? I don't want to reef on it until I know

how

Quoted message said:

Quoted message said:

the mechanism works. Any help appreciated.

Just loosen the bolt a bit, insert a pin or hook spanner (depending on the design of your
eccentric)

This is the part I'm not getting. How does a through bolt parallel to the BB axle keep the eccentric
from turning?

Quoted message said:

and turn the eccentric until you get the desired chain tension. Don't make it TOO tight - I have
had the best luck when I can get about 1/2" (1.2cm) of movement out of the chain at midspan.

I ride track so this part I'm familiar with. Phil Holman

Quoted message said:

Mark Hickey Habanero Cycles habcycles.comhabcycles.comOpen ↗ Home of the $695 ti frame

Quoted message said:

Just loosen the bolt a bit, insert a pin or hook spanner (depending on the design of your
eccentric), and turn the eccentric until you get the desired chain tension. Don't make it TOO
tight - I have had the best luck when I can get about 1/2" (1.2cm) of movement out of the chain
at midspan.

In my experience not that simple. The Cannondale uses a wedge to tighten the eccentric and it often
becomes stuck. Loosen the bolt a bit and tap it to loosen the wedge. If the bike's pretty new that
may work. If it's older it may be stuck in which case more force may have to be used. Don't use the
Allen, replace it with a hex head to beat on. Good luck. Phil brown

Phil Holman said:

"Mark Hickey" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Phil Holman said:

The chain on my newly acquired Canondale tandem is a tad on the slack side. There is a single
bolt that goes through the eccentric part

that

Quoted message said:

Quoted message said:

is easily removed. Now what? I don't want to reef on it until I know

how

Quoted message said:

Quoted message said:

the mechanism works. Any help appreciated.

Just loosen the bolt a bit, insert a pin or hook spanner (depending on the design of your
eccentric)

This is the part I'm not getting. How does a through bolt parallel to the BB axle keep the
eccentric from turning?

Sorry - you have a different eccentric than I do.

Quoted message said:

Quoted message said:

and turn the eccentric until you get the desired chain tension. Don't make it TOO tight - I have
had the best luck when I can get about 1/2" (1.2cm) of movement out of the chain at midspan.

I ride track so this part I'm familiar with. Phil Holman

Just remember the chain is a LOT longer than your track bike when you're checking the deflection.

Mark Hickey Habanero Cycles habcycles.comhabcycles.comOpen ↗ Home of the $695 ti frame

"Phil Brown" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Quoted message said:

Just loosen the bolt a bit, insert a pin or hook spanner (depending

on

Quoted message said:

Quoted message said:

the design of your eccentric), and turn the eccentric until you get the desired chain tension.
Don't make it TOO tight - I have had the best luck when I can get about 1/2" (1.2cm) of movement
out of the chain at midspan.

In my experience not that simple. The Cannondale uses a wedge to

tighten the

Quoted message said:

eccentric and it often becomes stuck. Loosen the bolt a bit and tap it

to

Quoted message said:

loosen the wedge. If the bike's pretty new that may work. If it's

older it may

Quoted message said:

be stuck in which case more force may have to be used. Don't use the

Allen,

Quoted message said:

replace it with a hex head to beat on. Good luck.

The tandem is a couple of years old but has less than 100miles on it. It has indications of grease
oozing out of the joint so I'm thinking it will loosen up easily enough. Thanks for the info.

Phil Holman

"Mark Hickey" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Phil Holman said:

"Mark Hickey" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

"Phil Holman" <[email hidden]> wrote:

>The chain on my newly acquired Canondale tandem is a tad on the

slack

Quoted message said:

Quoted message said:

Quoted message said:

>side. There is a single bolt that goes through the eccentric part

that

Quoted message said:

>is easily removed. Now what? I don't want to reef on it until I

know

Quoted message said:

Quoted message said:

how

Quoted message said:

>the mechanism works. Any help appreciated.

Just loosen the bolt a bit, insert a pin or hook spanner (depending

on

Quoted message said:

Quoted message said:

Quoted message said:

the design of your eccentric)

This is the part I'm not getting. How does a through bolt parallel to the BB axle keep the
eccentric from turning?

Sorry - you have a different eccentric than I do.

Quoted message said:

Quoted message said:

and turn the eccentric until you get the desired chain tension. Don't make it TOO tight - I
have had the best luck when I can get about 1/2" (1.2cm) of movement out of the chain at
midspan.

I ride track so this part I'm familiar with. Phil Holman

Just remember the chain is a LOT longer than your track bike when you're checking the deflection.

Good point and I'm looking at an inch of deflection at midspan. Like I said it's a tad too much.
Phil Brown's post identifies the right kind of eccentric so I'm off to the hardware store to find a
longer bolt. Thanks for your input.

Phil Holman

Quoted message said:

Mark Hickey Habanero Cycles habcycles.comhabcycles.comOpen ↗ Home of the $695 ti frame