Bottom bracket for Mavic 631(?) cranks?

"Memoria est thesaurus omnium rerum e custos." - Cicero
On Wed, 23 Mar 2005 07:06:39 -0700, Qui Si Parla Campagnolo
wrote:

John Dacey wrote:
I cannot recall ever having seen the taper type specified in any
official Mavic literature (why don't more manufacturers do this?), but
I believe the claim found elsewhere in this thread that it's JIS is in
error. Of the Mavic cranks I've ever seen installed on Shimano bottom
brackets, the crank did not drawn up on the spindle to the same
engagement depth as when partnered with a Mavic bottom bracket.

Well, my memory tells me that the taper was the same as UN-72, and they
did draw up and produce the samee chainline as the Mavic one.

The world of bicycles is replete with examples where the sum of
various errors either equals zero or comes close enough to be
considered to "work". Mismatching a blunter Shimano taper with its
shorter right side spindle overhang with a Mavic crank was a common
kludge where the combined cost of the apposite Mavic bottom bracket
and its installation was considered a barrier. In some cases, the
installer simply didn't have the requisite cutters to install a Mavic
610. That doesn't make it "correct", especially in the context of rbt.

Consider the photos below where a caliper is set at the end of a
Dura-Ace spindle (JIS) and then, without disturbing that caliper
setting, moved to one from Campagnolo (ISO) and finally to Mavic
(draw your own conclusion).
http://www.businesscycles.com/graphics/taper.jpg
http://www.businesscycles.com/graphics/taper2.jpg
http://www.businesscycles.com/graphics/taper3.jpg

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

In article 1111499769.5044348d752f98237789d90d56056b74@teran ews,
Qui Si Parla Campagnolo wrote:

Baird Webel wrote:
In article 1111355373.d4e41b739c67375c3294b37cc8a2d8a0@teran ews,
Qui Si Parla Campagnolo wrote:


James Thomson wrote:

I've just bought a pair of the last incarnation of Mavic's distinctive
"Starfish" cranks, date stamped 1995: the spider is slightly less
extravagant than the earlier model, and the arms are slightly 'low
profile'.

Can anybody tell me what bottom bracket lengths Mavic recommended for use
as a single, double or triple?


Single and double were 114mm, JIS taper, so any shimano one of this
length will work.


would not using the same spindle length on both single and double result
in a bad chainline for one of the applications?

Are you sure the taper is JIS? Were the older Mavic cranks JIS too?

Baird

They were JIS, we used un-72s all the time when somebody didn't want to
face the BB shell at 45 degrees for the Mavic BB.

I assumed as a 'single' you would put the single ring on the inside,
which would need a 114mm for frame clearance. I never saw a Mavic last
gen track crank that looked like the road one.

I guess this would make sense if you are using a ring smaller than would
fit because of the size of the spider and thus need the spacers.
Otherwise, I'd tend to put a shorter BB spindle and forgo the spacers.

I don't believe Mavic made a true 631 track crank, i.e. one with 144
BCD, though you could easily use a road 631 with a single ring. They
did do one that was numbered "636" but I believe it was more like the
637 MTB crank. I have what I believe is a set, pics are at:

http://homepage.mac.com/bwebel/cycli...toAlbum18.html

Baird

In article ,
"James Thomson" wrote:

"Qui Si Parla Campagnolo" wrote:

Single and double were 114mm, JIS taper, so any shimano
one of this length will work.

Thanks Peter.

I've just made a test fit on a UN72, and the taper fit doesn't look the
best. Are you certain it's JIS?


If John Dacey is correct and it is 114 with a longer right spindle, then
I wonder if a current campy Centaur BB for a triple wouldn't work well?
It is 115 with a longer right spindle, but who knows if the offset is
the same.

Another possibility might be the TA bottom bracket, though I'm not sure
if they are JIS or ISO these days, Or Phil Wood, which would let you
micro adjust the chainline a bit. I've been meaning to sit down with
the Mavic cranks I have and a bunch of BBs and try to work out the best
fit but haven't had the time. I'd be interested to hear what you end up
with.

Or, of course, troll Ebay for an actual Mavic one. Some of us still
have the tool to cut the champfer, though I haven't actually done it as
I found an old Vitus frame with it already cut. Doesn't look too hard,
though.

Baird

"Baird Webel" wrote:

I don't believe Mavic made a true 631 track crank, i.e. one
with 144 BCD, though you could easily use a road 631 with
a single ring. They did do one that was numbered "636"
but I believe it was more like the 637 MTB crank. I have what
I believe is a set, pics are at:

http://homepage.mac.com/bwebel/cycli...toAlbum18.html

The 637 arms were closer in shape to those of the 631, but the spider was a
more conventional 110/74 triple, of course.

Boardman's Lotus bike as shown here uses a crank that strongly resembles
the 637:

http://www.chrisboardman.co.uk/newpics/cbwall8.jpg

I've seen a set like yours on eBay once, but I don't know its model number.

James Thomson

"Baird Webel" wrote:

If John Dacey is correct and it is 114 with a longer right spindle,
then I wonder if a current campy Centaur BB for a triple wouldn't
work well? It is 115 with a longer right spindle, but who knows if
the offset is the same.

I understood that the Campag 115.5mm spindle was symmetrical. A 111 with a
spacer might do the trick.

Another possibility might be the TA bottom bracket, though I'm
not sure if they are JIS or ISO these days, Or Phil Wood, which
would let you micro adjust the chainline a bit. I've been meaning
to sit down with the Mavic cranks I have and a bunch of BBs
and try to work out the best fit but haven't had the time.

Stronglight still make a Mavic-style bottom bracket - the JP1000 - in
various lengths with ISO tapers:

http://www.zefal.com/stronglight/pag...keyProd=jp1000

I'd be interested to hear what you end up with.

I'll be sure to let you know.

James Thomson

John Dacey wrote:
"Memoria est thesaurus omnium rerum e custos." - Cicero
On Wed, 23 Mar 2005 07:06:39 -0700, Qui Si Parla Campagnolo
wrote:


John Dacey wrote:

I cannot recall ever having seen the taper type specified in any
official Mavic literature (why don't more manufacturers do this?), but
I believe the claim found elsewhere in this thread that it's JIS is in
error. Of the Mavic cranks I've ever seen installed on Shimano bottom
brackets, the crank did not drawn up on the spindle to the same
engagement depth as when partnered with a Mavic bottom bracket.


Well, my memory tells me that the taper was the same as UN-72, and they
did draw up and produce the samee chainline as the Mavic one.


The world of bicycles is replete with examples where the sum of
various errors either equals zero or comes close enough to be
considered to "work". Mismatching a blunter Shimano taper with its
shorter right side spindle overhang with a Mavic crank was a common
kludge where the combined cost of the apposite Mavic bottom bracket
and its installation was considered a barrier. In some cases, the
installer simply didn't have the requisite cutters to install a Mavic
610. That doesn't make it "correct", especially in the context of rbt.

Consider the photos below where a caliper is set at the end of a
Dura-Ace spindle (JIS) and then, without disturbing that caliper
setting, moved to one from Campagnolo (ISO) and finally to Mavic
(draw your own conclusion).
http://www.businesscycles.com/graphics/taper.jpg
http://www.businesscycles.com/graphics/taper2.jpg
http://www.businesscycles.com/graphics/taper3.jpg

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

I thought you said you didn't remember?

(draw your own conclusion).
http://www.businesscycles.com/graphics/taper.jpg
http://www.businesscycles.com/graphics/taper2.jpg
http://www.businesscycles.com/graphics/taper3.jpg

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

The last picture...it doesn't look like a mavic BB spindle....wonder
what it is??

John Dacey wrote:

Of the Mavic cranks I've ever seen installed on Shimano bottom
brackets, the crank did not drawn up on the spindle to the same
engagement depth as when partnered with a Mavic bottom bracket.

I can't locate any written specifics about symmetricality of the
various Mavic spindles. Working from memory (with all the attendant
caveats), I believe the 110 and 112 spindles were symmetrical, whereas

the 114, 116, 119 and 123 spindles all offered various amounts of
right side offsets.

I don't know the ins and outs, but my CRec crank seems to be happy, if
a little distant from the chainstay, on a "chamfer style" Mavic 114 BB.
I would have put Campy 111 in, but the frame is Ti, and a couple of the
local shops didn't want to chase the threads in far enough for the cups
to fit. Plus the outside edge of the BB shell is pretty thin where
chamfered... I seem to remember "some" offset on this BB, and it
comparing to the Campy Record 111 (farbon fiber cart) BB, except a few
silly millimeters longer.

Ahem, the OP... I've been told that the current (new, available for
purchase) Stronglight items "are the same thing" as the OOP Mavic BB's.
("Yeah. Sure.") Well, they look pretty close, but no idea of taper on
these:

http://www.zefal.com/stronglight/pag...keyProd=jp1000

OR (spreading the love): http://tinyurl.com/6wkwd

There's a "contact" link, which may help with tech questions. I had an
importer link, lost. "Not cheap" and neither are the used ones on
eeeebay. But you can probably use a Campy part, some styles of which
are easy to find and pay for. The experts must advise on
feasibility/selection (Centaur 115?). HTH --TP

On Thu, 24 Mar 2005 07:16:57 -0700, Qui Si Parla Campagnolo
wrote:

John Dacey wrote:
"Memoria est thesaurus omnium rerum e custos." - Cicero
On Wed, 23 Mar 2005 07:06:39 -0700, Qui Si Parla Campagnolo
wrote:


John Dacey wrote:

I cannot recall ever having seen the taper type specified in any
official Mavic literature (why don't more manufacturers do this?), but
I believe the claim found elsewhere in this thread that it's JIS is in
error. Of the Mavic cranks I've ever seen installed on Shimano bottom
brackets, the crank did not drawn up on the spindle to the same
engagement depth as when partnered with a Mavic bottom bracket.


Well, my memory tells me that the taper was the same as UN-72, and they
did draw up and produce the samee chainline as the Mavic one.


The world of bicycles is replete with examples where the sum of
various errors either equals zero or comes close enough to be
considered to "work". Mismatching a blunter Shimano taper with its
shorter right side spindle overhang with a Mavic crank was a common
kludge where the combined cost of the apposite Mavic bottom bracket
and its installation was considered a barrier. In some cases, the
installer simply didn't have the requisite cutters to install a Mavic
610. That doesn't make it "correct", especially in the context of rbt.

Consider the photos below where a caliper is set at the end of a
Dura-Ace spindle (JIS) and then, without disturbing that caliper
setting, moved to one from Campagnolo (ISO) and finally to Mavic
(draw your own conclusion).
http://www.businesscycles.com/graphics/taper.jpg
http://www.businesscycles.com/graphics/taper2.jpg
http://www.businesscycles.com/graphics/taper3.jpg


I thought you said you didn't remember?

I said I didn't recollect seeing it listed in any official spec's
published by Mavic. My _own_ memory is perhaps a millimeter or two
short of fully thesaural on the subject, but I liked the 610 bottom
brackets quite a lot when they were current models and used to do a
fair bit of work with them.

From your other follow-up post:

The last picture...it doesn't look like a mavic BB spindle....wonder
what it is??

It is, in fact, a genuine Mavic spindle.

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

On 24 Mar 2005 07:50:55 -0800, wrote:

John Dacey wrote:

Of the Mavic cranks I've ever seen installed on Shimano bottom
brackets, the crank did not drawn up on the spindle to the same
engagement depth as when partnered with a Mavic bottom bracket.

I can't locate any written specifics about symmetricality of the
various Mavic spindles. Working from memory (with all the attendant
caveats), I believe the 110 and 112 spindles were symmetrical, whereas

the 114, 116, 119 and 123 spindles all offered various amounts of
right side offsets.

I don't know the ins and outs, but my CRec crank seems to be happy, if
a little distant from the chainstay, on a "chamfer style" Mavic 114 BB.
I would have put Campy 111 in, but the frame is Ti, and a couple of the
local shops didn't want to chase the threads in far enough for the cups
to fit. Plus the outside edge of the BB shell is pretty thin where
chamfered... I seem to remember "some" offset on this BB, and it
comparing to the Campy Record 111 (farbon fiber cart) BB, except a few
silly millimeters longer.

If you're adventurous, you might try flipping the spindle's
orientation within the cartridge such that the end with the plus
offset is on the left. You'll still have an asymmetrical "stance" of
your pedals as measured from the bike's centerline, but you've got
that already now and using the spindle end with the shorter overhang
on the right might give you a better chainline.

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