Half a MM make any difference?

I'd like to swap a 52-42-30 105 crank out for either a Sugino XD600/XD300
46-36-26 square taper or the Nashbar Trekker 48-38-28 ISIS.

The bike, a Trek 520, came factory with a 68/118.5mm BB. Hardly anything is
available in a square taper and nothing that I can find in an ISIS, but
plenty of 118mm available. Will my chainline change much by the BB being off
..5 of a milimeter?

R Brickston wrote:
I'd like to swap a 52-42-30 105 crank out for either a Sugino XD600/XD300
46-36-26 square taper or the Nashbar Trekker 48-38-28 ISIS.

The bike, a Trek 520, came factory with a 68/118.5mm BB. Hardly anything is
available in a square taper and nothing that I can find in an ISIS, but
plenty of 118mm available. Will my chainline change much by the BB being off
.5 of a milimeter?

If you were using the same crank and just using different BB's, no.

However, since you're changing cranks, you'll need to use the
appropriate BB. Some "low-profile" cranks require 110mm BB's. It
appears the Sugino cranks use 118mm BB's
(http://www.sheldonbrown.com/harris/cranks.html#11074), so they should
bolt right on.

Jeff

"R Brickston" wrote in
news:EHvcg.3817$oA6.1493@trnddc06:

I'd like to swap a 52-42-30 105 crank out for either a Sugino
XD600/XD300 46-36-26 square taper or the Nashbar Trekker 48-38-28
ISIS.

The bike, a Trek 520, came factory with a 68/118.5mm BB. Hardly
anything is available in a square taper and nothing that I can find in
an ISIS, but plenty of 118mm available. Will my chainline change much
by the BB being off .5 of a milimeter?




It'll change more by using a 118. The XD cranks call for a 113, and I've
heard of people successfully using a 107 with it.. The spindle length is
determined by the crank, not the frame.

On the bright side, there are lots and lots and lots of reasonably good,
cheap 113 square taper BBs out there.

And definitely get the Sugino. Best crank deal in the universe.

"JeffWills" wrote in
oups.com:


R Brickston wrote:
I'd like to swap a 52-42-30 105 crank out for either a Sugino
XD600/XD300 46-36-26 square taper or the Nashbar Trekker 48-38-28
ISIS.

The bike, a Trek 520, came factory with a 68/118.5mm BB. Hardly
anything is available in a square taper and nothing that I can find
in an ISIS, but plenty of 118mm available. Will my chainline change
much by the BB being off .5 of a milimeter?

If you were using the same crank and just using different BB's, no.

However, since you're changing cranks, you'll need to use the
appropriate BB. Some "low-profile" cranks require 110mm BB's. It
appears the Sugino cranks use 118mm BB's
(http://www.sheldonbrown.com/harris/cranks.html#11074), so they should
bolt right on.

Jeff



118 is only if you have a 73mm shell. 68mm should use a 113.

"Hank Wirtz" wrote in message
6...
"JeffWills" wrote in
oups.com:


R Brickston wrote:
I'd like to swap a 52-42-30 105 crank out for either a Sugino
XD600/XD300 46-36-26 square taper or the Nashbar Trekker 48-38-28
ISIS.

The bike, a Trek 520, came factory with a 68/118.5mm BB. Hardly
anything is available in a square taper and nothing that I can find
in an ISIS, but plenty of 118mm available. Will my chainline change
much by the BB being off .5 of a milimeter?

If you were using the same crank and just using different BB's, no.

However, since you're changing cranks, you'll need to use the
appropriate BB. Some "low-profile" cranks require 110mm BB's. It
appears the Sugino cranks use 118mm BB's
(http://www.sheldonbrown.com/harris/cranks.html#11074), so they should
bolt right on.

Jeff



118 is only if you have a 73mm shell. 68mm should use a 113.

The 105 crank has a 68 x 188.5 Octalink V1, so with XD I'll try the 68 x
113.

R Brickston wrote:
I'd like to swap a 52-42-30 105 crank out for either a Sugino XD600/XD300
46-36-26 square taper or the Nashbar Trekker 48-38-28 ISIS.

The bike, a Trek 520, came factory with a 68/118.5mm BB. Hardly anything is
available in a square taper and nothing that I can find in an ISIS, but
plenty of 118mm available. Will my chainline change much by the BB being off
.5 of a milimeter?

Why don't you just put a 24, 26, or 28 tooth 74mm bcd inner chainring
on the bike? $10-$15 and 5 minutes and you are done. That is what I
did back in 1992 when I bought a Trek 520. Worked very well for many,
many years. Eventually went to a 20 tooth inner ring. You have bar
end shifters on the Trek 520 so there is no problems like STI has with
small inner chainrings.

wrote in message
ups.com...
R Brickston wrote:
I'd like to swap a 52-42-30 105 crank out for either a Sugino XD600/XD300
46-36-26 square taper or the Nashbar Trekker 48-38-28 ISIS.

The bike, a Trek 520, came factory with a 68/118.5mm BB. Hardly anything
is
available in a square taper and nothing that I can find in an ISIS, but
plenty of 118mm available. Will my chainline change much by the BB being
off
.5 of a milimeter?

Why don't you just put a 24, 26, or 28 tooth 74mm bcd inner chainring
on the bike? $10-$15 and 5 minutes and you are done. That is what I
did back in 1992 when I bought a Trek 520. Worked very well for many,
many years. Eventually went to a 20 tooth inner ring. You have bar
end shifters on the Trek 520 so there is no problems like STI has with
small inner chainrings.

I think you probably had a 110/74 BCD, this is a 105 5503 triple with a
130/94 and I understand a 30 tooth is as small as you can go. In any event,
that still leaves me with a 52 on top, almost unusable.

On Tue, 23 May 2006 03:54:12 GMT, "R Brickston"
wrote:

Will my chainline change much by the BB being off
.5 of a milimeter?

I doubt that you could measure the difference repeatably. But then,
there's a good chance that two nominally same-size BBs from different
sources would produce more of a variance than .5mm anyway.

Slap it in, check your sprocket and crank arm clearances at the stays,
and ride.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

R Brickston wrote:
wrote in message
ups.com...
R Brickston wrote:
I'd like to swap a 52-42-30 105 crank out for either a Sugino XD600/XD300
46-36-26 square taper or the Nashbar Trekker 48-38-28 ISIS.

The bike, a Trek 520, came factory with a 68/118.5mm BB. Hardly anything
is
available in a square taper and nothing that I can find in an ISIS, but
plenty of 118mm available. Will my chainline change much by the BB being
off
.5 of a milimeter?

Why don't you just put a 24, 26, or 28 tooth 74mm bcd inner chainring
on the bike? $10-$15 and 5 minutes and you are done. That is what I
did back in 1992 when I bought a Trek 520. Worked very well for many,
many years. Eventually went to a 20 tooth inner ring. You have bar
end shifters on the Trek 520 so there is no problems like STI has with
small inner chainrings.

I think you probably had a 110/74 BCD, this is a 105 5503 triple with a
130/94 and I understand a 30 tooth is as small as you can go.

You need to get yourself to a competent bike shop soon before you blow
all your money. Your Shimano 105 crankset has a 130mm bcd for the two
outer chainrings and 74mm bcd for the inner chainring. You can put as
low as a 24 tooth inner chainring on a 74mm bcd crank. You can go as
low as a 38 tooth chainring for either of the two outer rings. Only
the Shimano Dura Ace triple crankset has a goofy inner chainring size
of 92mm bcd or something. It only goes down to 30 tooth. Only Dura
Ace has this, not Ultegra or 105 or anything else on earth.

Yes my crank was a 110/74. It takes the exact same size inner
chainrings as a 130/74 crankset. The Sugino mentioned by the internet
bicyclists also is a 110/74. It takes the exact same size inner
chainring as your current Shimano 105.

Spend $10 and get a 24 or 26 74mm bcd inner chainring, put it on the
bike and be done with it. Don't blow your money on a crankset that you
don't need.

In any event,
that still leaves me with a 52 on top, almost unusable.

If the 52 is unusable, then don't use it with the smallest cogs. You
do know a 52x13 is an easier gear than a 46x11? The 46 is the top ring
on the Sugino cranks mentioned on this forum. 13 is your third cog on
your 11-32 cassette.

Internet bicyclists love to waste money.

wrote:
R Brickston wrote:
wrote in message
ups.com...
R Brickston wrote:
I'd like to swap a 52-42-30 105 crank out for either a Sugino XD600/XD300
46-36-26 square taper or the Nashbar Trekker 48-38-28 ISIS.

The bike, a Trek 520, came factory with a 68/118.5mm BB. Hardly anything
is
available in a square taper and nothing that I can find in an ISIS, but
plenty of 118mm available. Will my chainline change much by the BB being
off
.5 of a milimeter?

Why don't you just put a 24, 26, or 28 tooth 74mm bcd inner chainring
on the bike? $10-$15 and 5 minutes and you are done. That is what I
did back in 1992 when I bought a Trek 520. Worked very well for many,
many years. Eventually went to a 20 tooth inner ring. You have bar
end shifters on the Trek 520 so there is no problems like STI has with
small inner chainrings.

I think you probably had a 110/74 BCD, this is a 105 5503 triple with a
130/94 and I understand a 30 tooth is as small as you can go.

You need to get yourself to a competent bike shop soon before you blow
all your money. Your Shimano 105 crankset has a 130mm bcd for the two
outer chainrings and 74mm bcd for the inner chainring. You can put as
low as a 24 tooth inner chainring on a 74mm bcd crank. You can go as
low as a 38 tooth chainring for either of the two outer rings. Only
the Shimano Dura Ace triple crankset has a goofy inner chainring size
of 92mm bcd or something. It only goes down to 30 tooth. Only Dura
Ace has this, not Ultegra or 105 or anything else on earth.

Yes my crank was a 110/74. It takes the exact same size inner
chainrings as a 130/74 crankset. The Sugino mentioned by the internet
bicyclists also is a 110/74. It takes the exact same size inner
chainring as your current Shimano 105.

Spend $10 and get a 24 or 26 74mm bcd inner chainring, put it on the
bike and be done with it. Don't blow your money on a crankset that you
don't need.


Some more good advice. But a $13 26 tooth cog from Nashbar. 74mm bcd.
Put it on your Shimano 105 crankset. So you have 52-42-26. Also buy
from Nashbar a Shimano 105 9 speed cassette. $30 for a 13-23. It will
have loose cogs held together by three bolts. Take the bolts out. You
don't need them. Take off your current 11-32 9 speed cassette on your
Trek 520. Combine the 13-23 cassette and the 11-32 cassette and get a
new cassette going from 13 to 32. You will have more usable and lower
high gears with your 52-42-26 than if you waste money on the Sugino
46-36-26 crank and keep your current 11-32 cassette. Its the
combination of the big ring and the small cog and the wheel diameter
that determines your gear. 46x11 is higher than 52x13. Nashbar has a
10% off coupon code going now. So for less than $40, not including
shipping, you will have lower lows and lower highs and better spaced
cogs on your 9 speed Trek 520. Far superior to wasting money on a
Sugino crankset.



In any event,
that still leaves me with a 52 on top, almost unusable.

If the 52 is unusable, then don't use it with the smallest cogs. You
do know a 52x13 is an easier gear than a 46x11? The 46 is the top ring
on the Sugino cranks mentioned on this forum. 13 is your third cog on
your 11-32 cassette.

Internet bicyclists love to waste money.