Ultegra double crankset on a 105 triple bottom bracket?

I would like to upgrade my triple 'Cannondale Ex' cranks with a new
crankset.
I don't need a triple, and can get an Ultegra double for a decent
price. I currently have a 105 Octalink BB.

My question is can I install the Ultegra double on the triple (118?)
bracket, and just reset the derailleur limit screw?....or will I need
a new (double/ 109?) BB ?

I intend to eventually switch the front derailleur from a Tri to Dbl
but realize it is not essential.

(a while ago the crankbolt worked loose, and stripped the end of the
left crank a bit. I now have to retighten it every so often. It works
OK, but is my excuse to upgrade!)

Thanks all,
-Karl Roberts

2002 Cannondale R700Warrior Roadie

Urban Sherpa wrote:

I would like to upgrade my triple 'Cannondale Ex' cranks with a new
crankset.
I don't need a triple, and can get an Ultegra double for a decent
price. I currently have a 105 Octalink BB.

My question is can I install the Ultegra double on the triple (118?)
bracket, and just reset the derailleur limit screw?....or will I need
a new (double/ 109?) BB ?

You can do it, but the chainline will be sub-optimal. Actually the
chainline will be the same as if you just removed the inner chainring
from your triple crank. If you can tolerate this chainline, no reason
to change the BB.

I intend to eventually switch the front derailleur from a Tri to Dbl
but realize it is not essential.

(a while ago the crankbolt worked loose, and stripped the end of the
left crank a bit. I now have to retighten it every so often. It works
OK, but is my excuse to upgrade!)

It would be a lot cheaper to just buy a new left arm.

Sheldon "Sounds Like A 'Downgrade' To Me" Brown
+-----------------------------------------------+
| Who has deceived thee as often as thyself? |
| -- Benjamin Franklin |
+-----------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
http://harriscyclery.com
Hard-to-find parts shipped Worldwide
http://captainbike.com http://sheldonbrown.com

(Urban Sherpa) wrote in message . com...
I would like to upgrade my triple 'Cannondale Ex' cranks with a new
crankset.
I don't need a triple, and can get an Ultegra double for a decent
price. I currently have a 105 Octalink BB.

My question is can I install the Ultegra double on the triple (118?)
bracket, and just reset the derailleur limit screw?....or will I need
a new (double/ 109?) BB ?

I intend to eventually switch the front derailleur from a Tri to Dbl
but realize it is not essential.

(a while ago the crankbolt worked loose, and stripped the end of the
left crank a bit. I now have to retighten it every so often. It works
OK, but is my excuse to upgrade!)

Thanks all,
-Karl Roberts

2002 Cannondale R700Warrior Roadie

Of course you CAN mount the cranks on your current BB, but you don't
want to. The double cranks are designed to fit the 109mm BB spindle,
and putting them on a 118mm spindle means that each crank is 4.5mm
further out than it should be, which means that your pedals (and
therefore your feet) are further out. This will probably lead to
significant knee problems. Not to mention that you'll end up more
bow-legged than a pro bull rider! ;-

Spend the extra money, get the right BB.

urbansherpa-and can get an Ultegra double for a decent
price. I currently have a 105 Octalink BB.

My question is can I install the Ultegra double on the triple (118?)
bracket, and just reset the derailleur limit screw?....or will I need
a new (double/ 109?) BB ?

You can install the double onto the triple, 118.5mm BB but your chainline will
be horrible. You 'can' get the front der to work also, but again, the 109.5mm
is the peoper one...about $40 or so.



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

On 27 Sep 2004 15:14:21 -0700, (Scott Hendricks)
wrote:

(Urban Sherpa) wrote in message . com...
I would like to upgrade my triple 'Cannondale Ex' cranks with a new
crankset.
I don't need a triple, and can get an Ultegra double for a decent
price. I currently have a 105 Octalink BB.

My question is can I install the Ultegra double on the triple (118?)
bracket, and just reset the derailleur limit screw?....or will I need
a new (double/ 109?) BB ?

I intend to eventually switch the front derailleur from a Tri to Dbl
but realize it is not essential.

(a while ago the crankbolt worked loose, and stripped the end of the
left crank a bit. I now have to retighten it every so often. It works
OK, but is my excuse to upgrade!)

Thanks all,
-Karl Roberts

2002 Cannondale R700Warrior Roadie

Of course you CAN mount the cranks on your current BB, but you don't
want to. The double cranks are designed to fit the 109mm BB spindle,
and putting them on a 118mm spindle means that each crank is 4.5mm
further out than it should be, which means that your pedals (and
therefore your feet) are further out. This will probably lead to
significant knee problems. Not to mention that you'll end up more
bow-legged than a pro bull rider! ;-

Spend the extra money, get the right BB.

Why would this hurt him with a double but didn't hurt him back when he had the
triple on there? Should produce the same overall width as before.

I'll agree that narrower is generally better, but he's no more at risk for
injury with the double than before.

Then again, maybe your winkie applied to more than just the last sentence.

Ron

RonSonic wrote in message . ..
On 27 Sep 2004 15:14:21 -0700, (Scott Hendricks)
wrote:

(Urban Sherpa) wrote in message . com...
I would like to upgrade my triple 'Cannondale Ex' cranks with a new
crankset.
I don't need a triple, and can get an Ultegra double for a decent
price. I currently have a 105 Octalink BB.

My question is can I install the Ultegra double on the triple (118?)
bracket, and just reset the derailleur limit screw?....or will I need
a new (double/ 109?) BB ?

I intend to eventually switch the front derailleur from a Tri to Dbl
but realize it is not essential.

(a while ago the crankbolt worked loose, and stripped the end of the
left crank a bit. I now have to retighten it every so often. It works
OK, but is my excuse to upgrade!)

Thanks all,
-Karl Roberts

2002 Cannondale R700Warrior Roadie

Of course you CAN mount the cranks on your current BB, but you don't
want to. The double cranks are designed to fit the 109mm BB spindle,
and putting them on a 118mm spindle means that each crank is 4.5mm
further out than it should be, which means that your pedals (and
therefore your feet) are further out. This will probably lead to
significant knee problems. Not to mention that you'll end up more
bow-legged than a pro bull rider! ;-

Spend the extra money, get the right BB.

Why would this hurt him with a double but didn't hurt him back when he had the
triple on there? Should produce the same overall width as before.

I'll agree that narrower is generally better, but he's no more at risk for
injury with the double than before.

Then again, maybe your winkie applied to more than just the last sentence.

Ron

I'm assuming (key word: assuming) that the two cranks are designed for
the same Q factor, but not designed for the same BB. Mounting the
double on the triple BB would increase the Q factor greater than it,
or the triple, was designed for.

If in fact the Q factor of the triple is already 4.5mm wider, then
just disregard everything I said, as mounting the double crank on the
triple BB would result in the same Q factor.

RonSonic wrote in message . ..
On 27 Sep 2004 15:14:21 -0700, (Scott Hendricks)
wrote:

(Urban Sherpa) wrote in message . com...
I would like to upgrade my triple 'Cannondale Ex' cranks with a new
crankset.
I don't need a triple, and can get an Ultegra double for a decent
price. I currently have a 105 Octalink BB.

My question is can I install the Ultegra double on the triple (118?)
bracket, and just reset the derailleur limit screw?....or will I need
a new (double/ 109?) BB ?

I intend to eventually switch the front derailleur from a Tri to Dbl
but realize it is not essential.

(a while ago the crankbolt worked loose, and stripped the end of the
left crank a bit. I now have to retighten it every so often. It works
OK, but is my excuse to upgrade!)

Thanks all,
-Karl Roberts

2002 Cannondale R700Warrior Roadie

Of course you CAN mount the cranks on your current BB, but you don't
want to. The double cranks are designed to fit the 109mm BB spindle,
and putting them on a 118mm spindle means that each crank is 4.5mm
further out than it should be, which means that your pedals (and
therefore your feet) are further out. This will probably lead to
significant knee problems. Not to mention that you'll end up more
bow-legged than a pro bull rider! ;-

Spend the extra money, get the right BB.

Why would this hurt him with a double but didn't hurt him back when he had the
triple on there? Should produce the same overall width as before.

I'll agree that narrower is generally better, but he's no more at risk for
injury with the double than before.

Then again, maybe your winkie applied to more than just the last sentence.

Ron

I'm assuming (key word: assuming) that the two cranks are designed for
the same Q factor, but not designed for the same BB. Mounting the
double on the triple BB would increase the Q factor greater than it,
or the triple, was designed for.

If in fact the Q factor of the triple is already 4.5mm wider, then
just disregard everything I said, as mounting the double crank on the
triple BB would result in the same Q factor.

Urban Sherpa wrote:
I would like to upgrade my triple 'Cannondale Ex' cranks with a new
crankset.
I don't need a triple, and can get an Ultegra double for a decent
price. I currently have a 105 Octalink BB.

My question is can I install the Ultegra double on the triple (118?)
bracket, and just reset the derailleur limit screw?....or will I need
a new (double/ 109?) BB ?

I intend to eventually switch the front derailleur from a Tri to Dbl
but realize it is not essential.

(a while ago the crankbolt worked loose, and stripped the end of the
left crank a bit. I now have to retighten it every so often. It works
OK, but is my excuse to upgrade!)

How are you tightening it? Shimano recommends 50Nm on the crank bolts,
which I think is around 37 Ft lbs. You will not get that with an alan
wrench. Use a torque wrench, and you will find it probably won't loosen
up any more.


--
Mark Wolfe Lakeside, ca http://www.wolfenet.org
gpg fingerprint = 42B6 EFEB 5414 AA18 01B7 64AC EF46 F7E6 82F6 8C71
"I hate Windows NT because everytime I wear my Blu-Blockers the
dang monitor disappears!"

Urban Sherpa wrote:
I would like to upgrade my triple 'Cannondale Ex' cranks with a new
crankset.
I don't need a triple, and can get an Ultegra double for a decent
price. I currently have a 105 Octalink BB.

My question is can I install the Ultegra double on the triple (118?)
bracket, and just reset the derailleur limit screw?....or will I need
a new (double/ 109?) BB ?

I intend to eventually switch the front derailleur from a Tri to Dbl
but realize it is not essential.

(a while ago the crankbolt worked loose, and stripped the end of the
left crank a bit. I now have to retighten it every so often. It works
OK, but is my excuse to upgrade!)

How are you tightening it? Shimano recommends 50Nm on the crank bolts,
which I think is around 37 Ft lbs. You will not get that with an alan
wrench. Use a torque wrench, and you will find it probably won't loosen
up any more.


--
Mark Wolfe Lakeside, ca http://www.wolfenet.org
gpg fingerprint = 42B6 EFEB 5414 AA18 01B7 64AC EF46 F7E6 82F6 8C71
"I hate Windows NT because everytime I wear my Blu-Blockers the
dang monitor disappears!"