Spacer on DA7800 bb/crankset

Jens wrote:
Mike,

It's actually a new P3 Carbon with a DA SRM crankset. The problem is
that the SRM has a plastic cover over the electronics on the inside of
the
driveside crank. It protrudes inward maybe a millimeter. This is the
part
that rubs.

Here's a picture of one that has a spacer added:

http://i21.photobucket.com/albums/b2...0/DSC00262.jpg

I've heard that the CSC and Rabobank teams have had
to deal with this problem too. It sounds like they've opted for the
spacer solution.

cheers, Jens

ride it foir a bit and then take the left arm off and see if there is
any rubbage. If not-bob's yer uncle.

I've heard that the CSC and Rabobank teams have had
to deal with this problem too. It sounds like they've opted for the
spacer solution.

cheers, Jens

ride it foir a bit and then take the left arm off and see if there is
any rubbage. If not-bob's yer uncle.

I'm with you on this one; any slight flex in the BB isn't going to affect it
too much, since the diameter is pretty small. Plus, you don't have to worry
about anything moving in over time, because the crank arm location is
absolutely fixed.

But I'm missing out on the "bob's yer uncle" part. Is that a red state
expression? :)

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


"Qui si parla Campagnolo" wrote in message
oups.com...

Jens wrote:
Mike,

It's actually a new P3 Carbon with a DA SRM crankset. The problem is
that the SRM has a plastic cover over the electronics on the inside of
the
driveside crank. It protrudes inward maybe a millimeter. This is the
part
that rubs.

Here's a picture of one that has a spacer added:

http://i21.photobucket.com/albums/b2...0/DSC00262.jpg

I've heard that the CSC and Rabobank teams have had
to deal with this problem too. It sounds like they've opted for the
spacer solution.

cheers, Jens

ride it foir a bit and then take the left arm off and see if there is
any rubbage. If not-bob's yer uncle.

Mike Jacoubowsky wrote:


But I'm missing out on the "bob's yer uncle" part. Is that a red state
expression? :)

--Mike-- Chain Reaction Bicycles


If it works, great, go ride it. -'bob's yer uncle'. Not sure where it
came from, heard it first here on this NG-

Mike Jacoubowsky wrote:
ride it foir a bit and then take the left arm off and see if there is
any rubbage. If not-bob's yer uncle.

But I'm missing out on the "bob's yer uncle" part. Is that a red state
expression? :)

Maybe a redcoat expression...

http://alt-usage-english.org/excerpts/fxbobsyo.html

Well, OK, the saying seems to have come about after the US Revolutionary
war. I like the phrase, but I don't know why.

--
Dave

dvt wrote:
Mike Jacoubowsky wrote:
ride it foir a bit and then take the left arm off and see if there
is any rubbage. If not-bob's yer uncle.

But I'm missing out on the "bob's yer uncle" part. Is that a red
state expression? :)

Maybe a redcoat expression...

http://alt-usage-english.org/excerpts/fxbobsyo.html

Well, OK, the saying seems to have come about after the US
Revolutionary war. I like the phrase, but I don't know why.

Didn't it make it into an Austin Powers movie?

That sent me to Google, which in turn produced:
http://www.effingpot.com/slang.shtml

HAND! BS!

On 4 Nov 2005 05:35:29 -0800, "Qui si parla Campagnolo"
wrote:


John Dacey wrote:
On 2 Nov 2005 18:32:23 -0800, "Jens" wrote:

I need to move the drive side of my Dura-ace 7800 crankset
about a mm out from my frame, due to rubbing problems.
Doing searches, I don't see any references to spacers for
the 7800. Do they exist? Any foreseeable problems with putting
one on the drive side?

Put a 1mm spacer (the sort used for shimming fixed cups and freewheels
for ages) between the right bearing cup and the bottom bracket shell.


As I mentioned, that will effectively make the BB shell 69MM(thanks
Phil)...and when tightening the left arm, it will rub onto the left
cup. On the 7800 crank it's essential that the crank arm go onto the
'spindle'' and then stop at the spline ends. Otherwise, it will drag on
the cup.

I don't understand what you're trying to say here. Proper installation
of the crank mandates that the left crank be tightened against the
plastic bearing cover in the left cup. (There's even a tightening spec
for the cap for those trying to get maximum value from their
torque-wrench investments). If you limit how far the left arm is
pushed onto the spindle as you describe above, you'll likely have
lateral play in the crank together with the creaks, groans and other
noises associated with a sloppy fit. The "rubbing" you're trying so
hard to avoid isn't a bad thing--it's essential!

-------------------------------
John Dacey
Business Cycles, Miami, Florida
Since 1983
Comprehensive catalogue of track equipment: online since 1996
http://www.businesscycles.com
-------------------------------

John Dacey wrote:
On 4 Nov 2005 05:35:29 -0800, "Qui si parla Campagnolo"
wrote:


John Dacey wrote:
On 2 Nov 2005 18:32:23 -0800, "Jens" wrote:

I need to move the drive side of my Dura-ace 7800 crankset
about a mm out from my frame, due to rubbing problems.
Doing searches, I don't see any references to spacers for
the 7800. Do they exist? Any foreseeable problems with putting
one on the drive side?

Put a 1mm spacer (the sort used for shimming fixed cups and freewheels
for ages) between the right bearing cup and the bottom bracket shell.


As I mentioned, that will effectively make the BB shell 69MM(thanks
Phil)...and when tightening the left arm, it will rub onto the left
cup. On the 7800 crank it's essential that the crank arm go onto the
'spindle'' and then stop at the spline ends. Otherwise, it will drag on
the cup.

I don't understand what you're trying to say here. Proper installation
of the crank mandates that the left crank be tightened against the
plastic bearing cover in the left cup. (There's even a tightening spec
for the cap for those trying to get maximum value from their
torque-wrench investments). If you limit how far the left arm is
pushed onto the spindle as you describe above, you'll likely have
lateral play in the crank together with the creaks, groans and other
noises associated with a sloppy fit. The "rubbing" you're trying so
hard to avoid isn't a bad thing--it's essential!

Hardly essential. If you install onto a 66mm shell, and push the left
arm onto the spindle with the plastic cap, the crank will barely turn.


-------------------------------
John Dacey
Business Cycles, Miami, Florida
Since 1983
Comprehensive catalogue of track equipment: online since 1996
http://www.businesscycles.com
-------------------------------

On 8 Nov 2005 06:03:31 -0800, "Qui si parla Campagnolo"
wrote:


cup. On the 7800 crank it's essential that the crank arm go onto the
'spindle'' and then stop at the spline ends. Otherwise, it will drag on
the cup.

I don't understand what you're trying to say here. Proper installation
of the crank mandates that the left crank be tightened against the
plastic bearing cover in the left cup. (There's even a tightening spec
for the cap for those trying to get maximum value from their
torque-wrench investments). If you limit how far the left arm is
pushed onto the spindle as you describe above, you'll likely have
lateral play in the crank together with the creaks, groans and other
noises associated with a sloppy fit. The "rubbing" you're trying so
hard to avoid isn't a bad thing--it's essential!

Hardly essential. If you install onto a 66mm shell, and push the left
arm onto the spindle with the plastic cap, the crank will barely turn.

I am struck by the incidence of bottom bracket shells that you seem to
encounter that're over/under their nominal width. It's a statistical
anomaly that easily rivals the record of broken cranks and
crankbearing spindles that Jobst B has suffered. It's even more
astonishing to think that all the ones you reference in this thread
are limited to those in which Shimano 10 cranks are installed!

Even so, I'm further perplexed over the reason that the crank wouldn't
turn in the installation you mention. Perhaps the plastic bearing
shield deformed when compressed between two cups that were unusually
closely spaced such that the shield then pressed directly on the crank
spindle and caused sluggish rotation. Otherwise, I can't identify any
reason for the bearings to bind unless the cap tightening the left
crank on the spindle were grossly overtorqued.

-------------------------------
John Dacey
Business Cycles, Miami, Florida
Since 1983
Comprehensive catalogue of track equipment: online since 1996.
http://www.businesscycles.com

John Dacey wrote:


I am struck by the incidence of bottom bracket shells that you seem to
encounter that're over/under their nominal width. It's a statistical
anomaly that easily rivals the record of broken cranks and
crankbearing spindles that Jobst B has suffered. It's even more
astonishing to think that all the ones you reference in this thread
are limited to those in which Shimano 10 cranks are installed!

Since we start with framesets, not complete bicyclkes, we see a lot of
frames that are not prepped and many are not the 68mm you seem to see.
Fetish, Empella come to mind,, both of which were 70mm before
facing(BSC BBs). NOT limited to shimano cranks but to any external BB
crank, like FDA and Truvativ...

Even so, I'm further perplexed over the reason that the crank wouldn't
turn in the installation you mention. Perhaps the plastic bearing
shield deformed when compressed between two cups that were unusually
closely spaced such that the shield then pressed directly on the crank
spindle and caused sluggish rotation. Otherwise, I can't identify any
reason for the bearings to bind unless the cap tightening the left
crank on the spindle were grossly overtorqued.

I have no answer as to why you are perplexed....

-------------------------------
John Dacey
Business Cycles, Miami, Florida
Since 1983
Comprehensive catalogue of track equipment: online since 1996.
http://www.businesscycles.com