Shimano BB / Sugino XD compatibility
Joel
currently has shimano 600 bb and crankset (8 speed square taper). The
lowest cost soultion seems to be Sugino XD cranks which seem to come in
a variery of double or triple configurations. I found a Sugino XD2
double which recommends using a 110 mm BB. I think my BB is 113 mm but
not sure. Can I just shift the BB by 1 or 2 mm to make up the
difference or do i really need a 110 mm BB. What size BB would I need
for a triple Sugino XD, I think they are less expensive.
Thanks - Joel
David L. Johnson
Probably the 113mm bottom bracket would give you not such a great
chainline. Getting the 110 would probably be better. Going to a triple
in order to avoid the $20 expense of a bottom bracket does not strike me
as a great decision. If you want the triple, get it, but if the only
reason you are getting it is to avoid replacing the old bottom bracket,
that is, frankly, silly.
Expense aside, a triple will be somewhat fussier to shift. Setting up the
front shifter will take considerably more care with the triple, or you
will find yourself downshifting too far (from the big to the granny,
skipping the middle ring), which can be awkward.
--
David L. Johnson
__o | As far as the laws of mathematics refer to reality, they are not
_`\(,_ | certain, and as far as they are certain, they do not refer to
(_)/ (_) | reality. -- Albert Einstein
Joel
The XD2 double appears to have pins on chianrings ala Shimano which
would likely improve shifting. I have a Shimano compact double on my
race bike and it works great.
Joel
David L. Johnson
If you are going to do something like that, you should more seriously
worry about chainline and BB width. I use a MTB compact crank (94/58mm)
on my road bike, using only the outer two positions. It is also a Sugino.
I undersized the bottom bracket since most of the time I would not be
using a granny - though I have used it for loaded touring, and it shifts
fine as a very-compact double.
What I said still applies: don't buy the triple just to use a longer
bottom bracket. To use the triple as a double (using the outer two
positions), you will want a shorter bb. If you use the inner two
positions, you might even want a longer bb than specified, but I would
try the 113 you have first.
--
David L. Johnson
__o | When you are up to your ass in alligators, it's hard to remember
_`\(,_ | that your initial objective was to drain the swamp. -- LBJ
(_)/ (_) |
Nate Knutson
If the XD2 gets good chainline with a 110 (which it certainly might,
but it's not the most common crank so you likely won't be able to know
until you try), then using a 113 with it is slightly less than optimal
but basically okay. If XD2s get chainline that's a bit out with a 110,
meaning Sugino just specced 110 to avoid clearance issues at the cost
of more mediocre chainline for anyone who doesn't second-guess them,
then you may very well run into issues if you use a 113. Sugino does
exactly that on some of their cranks.
The only type of BB's that will let you "shift" the spindle left like
you mention are cartridge BB's with shouldered left cups or no
shouldered cups, which I'm almost positive excludes your 600.
XD300s and XD600s spec a 113 but chainline for the 135-based setups
they're made for is usually better if you can get away with a 110,
which will work fine clearance-wise on some frames but not all. This
means that if your bike is 126 or 130 in back, then the chainline is
going to be quite far from optimal even using a 113 spindle.
If the XD2 sounds like what you want, and you want to be pretty sure
everything is going to go smoothly the first time around, you should
probably just get it and a 110 to go with it.
Qui si parla Campagnolo
Just put it on...1.5mm or so difference or at the most 3mm on one
side..not a big deal, tapers are the same.
wayne...@gmail.com
>What size BB would I need
> for a triple Sugino XD, I think they are less expensive.
Keep your BB, 2-3mm would be no big deal. I use an XD triple crank
with 113 BB and 130 rear spacing. Middle ring is dead in the middle of
cassette. Use it as double or triple - great crank.
wayne...@gmail.com
>What size BB would I need
> for a triple Sugino XD, I think they are less expensive.
Keep your BB, 2-3mm would be no big deal. I use an XD triple crank
Booker C. Bense
In article <C6mdndhz_8I...@ptd.net>,
David L. Johnson <david....@lehigh.edu> wrote:
>On Tue, 24 Oct 2006 19:56:19 -0700, Joel wrote:
>
>> I would like to switch to a compact crankset on my commuter bike which
>> currently has shimano 600 bb and crankset (8 speed square taper). The
>> lowest cost soultion seems to be Sugino XD cranks which seem to come in
>> a variery of double or triple configurations. I found a Sugino XD2
>> double which recommends using a 110 mm BB. I think my BB is 113 mm but
>> not sure. Can I just shift the BB by 1 or 2 mm to make up the
>> difference or do i really need a 110 mm BB. What size BB would I need
>> for a triple Sugino XD, I think they are less expensive.
>
>Probably the 113mm bottom bracket would give you not such a great
>chainline.
3mm/2 = 1.5mm (i.e. exactly the difference between a road triple
and double chainline 43.5 vs 45mm )
I'd worry about 1.5mm for a fixed gear bike, but not for a bike
with a derailler. Get the XD and try it, if it doesn't work well
then maybe get a new BB.
The only posssible worry would be if you have Shimano Brifters on
the bike and a triple crank. The indexing for the shimano front
shifting is a bit finicky and really wants everything aligned.
However if you stick to the compact setup, then it should not
be that much of a problem. If you have friction shifters or
Campagnolo then it's no worries.
As far as I can tell the only difference between the XD triple
and doubles is that the doubles have had the fittings for the
inner triple ring machined off. If you get the triple and just
leave the inner chainring off, you keep all your options open
at the cost of just a bit of added weight.
_ Booker C. Bense
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Stephen Greenwood
I use a setup similar to what you're proposing on a road bike I built
up. It's a Sugino XD2 110mm BCD crank, a 107mm Shimano UN-52 bottom
bracket, and an 8-speed cassette (130mm rear hub spacing). The crank is
a triple, but I removed the smallest ring. It works well like this.
Without knowledge of the specifics of your frame, it's hard to say
whether this would work for you; I'd guess not, but there could be
clearance problems.
I chose the triple for two reasons. First, the stock chainwheels on
this crank were (are?) 46/36/24. Using only 46/36 gives me two rings
that are effectively in the spaces between the 52/42/30 of many modern
"road triples". I used a 52/42/30 for a year or two, but never needed
the extreme ends of the gearing range. These two rings with a 12-28
cassette give me all the range I need. Second, having a triple allows
you to use it as a double, but you can change your mind and use it as a
triple later. You might need a different bottom bracket, but those are
cheap, and if your shifter is not indexed, you won't need a new one of
those.