Bottom bracket replacement fitting

[trg]

I am replacing the bottom bracket on my 1990 Trek MTB (Deore LX triple
crankset). The BB measures 68mm and the spindle 133mm in length. I want to
replace the BB with a cartridge, but I haven't found any that are 68/133.
The closest I've seen is 68/127. Does a 68/133 cartridge BB exist? If not,
can I use the 68/127 BB?

Thanks

-trg

[JeffWills]

trg wrote:
> I am replacing the bottom bracket on my 1990 Trek MTB (Deore LX triple
> crankset). The BB measures 68mm and the spindle 133mm in length. I want to
> replace the BB with a cartridge, but I haven't found any that are 68/133.
> The closest I've seen is 68/127. Does a 68/133 cartridge BB exist? If not,
> can I use the 68/127 BB?
>
> Thanks
>
> -trg

122 or 122.5mm would be what I'd expect for that era bike. A 127mm
might be needed to clear fat chainstays- something I wouldn't expect on
your Trek.

How did you measure the spindle length?

Jeff

[trg]

"JeffWills" > a écrit dans le message de news:
om...
>
> trg wrote:
>> I am replacing the bottom bracket on my 1990 Trek MTB (Deore LX triple
>> crankset). The BB measures 68mm and the spindle 133mm in length. I want
>> to
>> replace the BB with a cartridge, but I haven't found any that are 68/133.
>> The closest I've seen is 68/127. Does a 68/133 cartridge BB exist? If
>> not,
>> can I use the 68/127 BB?
>>
>> Thanks
>>
>> -trg
>
> 122 or 122.5mm would be what I'd expect for that era bike. A 127mm
> might be needed to clear fat chainstays- something I wouldn't expect on
> your Trek.
>
> How did you measure the spindle length?
>
> Jeff
>

From end to end as shown in D in Sheldon's picture (measurement D)-
http://www.sheldonbrown.com/harris/images/spindle.jpg

In addition, the other measurements (A,B,C) also conform to this spindle-
Part Number CR4205
Size Code 3TR-B
Shell Width 68
D Length Overall 133
A Length Left End 42
B Length Middle 52
C LengthRight End 39
http://www.sheldonbrown.com/harris/bottombrackets.html



Sheldon agrees with you. According to
http://www.sheldonbrown.com/bbsize.html#deore , the spindle should be
122.5mm.

I bought the bike used around '92. I suppose it's possible that someone had
replaced the BB with too long a spindle. I didn't measure the chainline
before taking apart the BB, but I've never had a problem shifting, Although
I always had the impression that the left crank looked like it stuck out a
bit too much.

[Qui si parla Campagnolo]

trg wrote:
> I am replacing the bottom bracket on my 1990 Trek MTB (Deore LX triple
> crankset). The BB measures 68mm and the spindle 133mm in length. I want to
> replace the BB with a cartridge, but I haven't found any that are 68/133.
> The closest I've seen is 68/127. Does a 68/133 cartridge BB exist? If not,
> can I use the 68/127 BB?
>
> Thanks
>
> -trg

Sure, use a shimano 127mmby68 cart bearing BB-it will work fine.

[Nate Knutson]

trg wrote:
> I am replacing the bottom bracket on my 1990 Trek MTB (Deore LX triple
> crankset). The BB measures 68mm and the spindle 133mm in length. I want to
> replace the BB with a cartridge, but I haven't found any that are 68/133.
> The closest I've seen is 68/127. Does a 68/133 cartridge BB exist? If not,
> can I use the 68/127 BB?
>
> Thanks
>
> -trg

How well or if 127 will work depends on chainline and clearance issues,
both of which can only be checked by you. It will probably work.

Phil makes 130 and 135 but it's probably not worth it.

[John Henderson]

trg wrote:

> Does a 68/133 cartridge BB exist?

If you need that size, yes, St John Street Cycles (UK) sells
them. See http://www.sjscycles.com/store/vIndex.htm Under BB,
taper square sealed, look for "Budget sealed bearing tapered
bottom bracket with steel shimano splined cups".

I used one once on a SRAM/Sachs Spectro S7 hub with an unusual
chainwheel setup.

John

[A Muzi]

>>trg wrote:
>>>I am replacing the bottom bracket on my 1990 Trek MTB (Deore LX triple
>>>crankset). The BB measures 68mm and the spindle 133mm in length. I want
>>>to
>>>replace the BB with a cartridge, but I haven't found any that are 68/133.
>>>The closest I've seen is 68/127. Does a 68/133 cartridge BB exist? If
>>>not,
>>>can I use the 68/127 BB?

> "JeffWills" >
>>122 or 122.5mm would be what I'd expect for that era bike. A 127mm
>>might be needed to clear fat chainstays- something I wouldn't expect on
>>your Trek.
>>How did you measure the spindle length?

trg wrote:
> From end to end as shown in D in Sheldon's picture (measurement D)-
> http://www.sheldonbrown.com/harris/images/spindle.jpg
> In addition, the other measurements (A,B,C) also conform to this spindle-
> Part Number CR4205 Size Code 3TR-B Shell Width 68
> D Length Overall 133
> A Length Left End 42
> B Length Middle 52
> C LengthRight End 39
> http://www.sheldonbrown.com/harris/bottombrackets.html
> Sheldon agrees with you. According to
> http://www.sheldonbrown.com/bbsize.html#deore , the spindle should be
> 122.5mm.
>
> I bought the bike used around '92. I suppose it's possible that someone had
> replaced the BB with too long a spindle. I didn't measure the chainline
> before taking apart the BB, but I've never had a problem shifting, Although
> I always had the impression that the left crank looked like it stuck out a
> bit too much.

Normally the right side is longer.
When one does not have the correct spindle it's common to
flip one over.

If your spindle was truly set up with the 39 on the right,
your left crank will be outboard more than necessary, as you
noted. A shorter spindle, say a more common 3T or 3M with a
39 right would do it, just as Jeff Wills suggested.

Write back with your crank model and we'll advise on the
recommended spindle - yours does not seem original. The most
likley is a 3-S, 122.5mm with 37.5 right.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

[A Muzi]

> trg wrote:
>>I am replacing the bottom bracket on my 1990 Trek MTB (Deore LX triple
>>crankset). The BB measures 68mm and the spindle 133mm in length. I want to
>>replace the BB with a cartridge, but I haven't found any that are 68/133.
>>The closest I've seen is 68/127. Does a 68/133 cartridge BB exist? If not,
>>can I use the 68/127 BB?

Qui si parla Campagnolo wrote:
> Sure, use a shimano 127mmby68 cart bearing BB-it will work fine.

He mentioned that the 133 spindle was in backwards, 39mm
right. Maybe a standard 122.5 as the early LX is spec'd with.

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

[A Muzi]

-snip much all through-
>>>>trg wrote:
>>>>>I am replacing the bottom bracket on my 1990 Trek MTB (Deore LX triple
>>>>>crankset).

>>>"JeffWills" >
>>>>122 or 122.5mm would be what I'd expect for that era bike.

>>trg wrote:
>>>According to
>>>http://www.sheldonbrown.com/bbsize.html#deore , the spindle should be
>>>122.5mm.
>>>
>>>I bought the bike used around '92.

> "A Muzi" >
>>Normally the right side is longer.
>>When one does not have the correct spindle it's common to flip one over.

>>spindle - yours does not seem original. The most likley is a 3-S, 122.5mm
>>with 37.5 right.

trg wrote:> It was 39 right and 42 left. As I indicated, the
crank is a Deore LX Triple
> (175mm) circa 1990, so I guess the 68/122.5 is the way to go.

I'm sorry I skipped past your crank description the first
time. An LX of that era is a 3-S certainly. Not to worry.

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971

[trg]

"A Muzi" > a écrit dans le message de news:
...
>> trg wrote:
>>>I am replacing the bottom bracket on my 1990 Trek MTB (Deore LX triple
>>>crankset). The BB measures 68mm and the spindle 133mm in length. I want
>>>to
>>>replace the BB with a cartridge, but I haven't found any that are 68/133.
>>>The closest I've seen is 68/127. Does a 68/133 cartridge BB exist? If
>>>not,
>>>can I use the 68/127 BB?
>
> Qui si parla Campagnolo wrote:
>> Sure, use a shimano 127mmby68 cart bearing BB-it will work fine.
>
> He mentioned that the 133 spindle was in backwards, 39mm right. Maybe a
> standard 122.5 as the early LX is spec'd with.
>

According to the info I quoted above from Sheldon's page, 39 right is not
backwards for that BB. If I use a standard122.5 with 37.5 right, that will
bring in the left crank 9mm, won't it?

[A Muzi]

>>>trg wrote:
>>>>I am replacing the bottom bracket on my 1990 Trek MTB (Deore LX triple
>>>>crankset). The BB measures 68mm and the spindle 133mm in length. I want
>>>>to
>>>>replace the BB with a cartridge, but I haven't found any that are 68/133.
>>>>The closest I've seen is 68/127. Does a 68/133 cartridge BB exist? If
>>>>not,
>>>>can I use the 68/127 BB?

>>Qui si parla Campagnolo wrote:
>>>Sure, use a shimano 127mmby68 cart bearing BB-it will work fine.

> "A Muzi" >
>>He mentioned that the 133 spindle was in backwards, 39mm right. Maybe a
>>standard 122.5 as the early LX is spec'd with.

trg wrote:
> According to the info I quoted above from Sheldon's page, 39 right is not
> backwards for that BB. If I use a standard122.5 with 37.5 right, that will
> bring in the left crank 9mm, won't it?

Yes it will. A 3-S is 37.5 right and 35 left.

(The next spindle, with kickstand clearance, is a 3T at 39
and 35)

And my comment about 'backwards' stems from your report of
the spindle you found with the long side left. IMHO some
mechanic didn't have a 3S handy and made a common and
reasonable swap , keeping the chain side about 37~39mm.

That said, modern a cartridge type BBs are symmetric. A
current 122.5 will be too short on the right for your
classic LX crank. Add a spacer to your 122.5 or run a 127
cartridge if you decide not to use a 3-S spindle with new
retainers.

p.s. fitting loose spindles with uncertainty, we slip the BB
in the bike dry. to check chainline.

--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971