reasons for integrated bottom brackets?

Chris Esposito said:

A number of cranksets are advertising that they have integrated bottom brackets, and list reduced weight and increased stiffness as advantages of doing so. Do these claims hold? Are they really lighter and stiffer than a pair of separate components?

Any downsides to doing this sort of integration? It would seem that if either the crankset or bottom bracket had a problem, you would have to replace both.

Chris

See the thread on Crankset BB technology I started about 3 weeks ago.

The answer seems to be that the jury is still out on whether this is
an improvement for the rider or just the marketing people.

I recently bought one of these integrated crankset/BB thingies but
haven't yet installed it. It sure looks nice.

<< A number of cranksets are advertising that they have integrated bottom =
brackets, and list reduced weight and increased stiffness as advantages =
of doing so. Do these claims hold? Are they really lighter and stiffer =
than a pair of separate components? >><BR><BR>

Yes they are 'stiffer and lighter' but imply that the older stuff is 'heavy and
flexy' which is crappola.

Stiffness is measured by some gorilla sized machine that proiduces way more
force than any human.

Remember they are way more expensive as well.

AND the ultegra one is heavier than Centaur crank/BB, but $100 more expensive.

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

Chris Esposito said:

A number of cranksets are advertising that they have integrated bottom
brackets, and list reduced weight and increased stiffness as advantages
of doing so. Do these claims hold? Are they really lighter and stiffer
than a pair of separate components?

yes. see dianne1234's posting a few weeks back. she posted a scanned
article from a french mag that did extensive testing on the subject.

Quoted message said:

Any downsides to doing this sort of integration? It would seem that if
either the crankset or bottom bracket had a problem, you would have to
replace both.

there's no down side. the only reason to replace a separate bb is
because the bearings have failed. and as bearings are separately
replaceable on integrated crank/bb combo's, that's not a problem. the
average crank arm outlives the average bb bearing many times so the
reverse argument about needing to replace the crank before the bearings
doesn't present a problem in reality either.

Quoted message said:

Chris

On Wed, 2 Feb 2005 20:15:07 -0800, "Chris Esposito"

may have said:

A number of cranksets are advertising that they have integrated
bottom brackets, and list reduced weight and increased stiffness
as advantages of doing so. Do these claims hold? Are they really
lighter and stiffer than a pair of separate components?

Yes, they're stiffer than the typical previous designs used on road
bikes, and yes, they're lighter than most conventional BB and crank
assemblies.

Quoted message said:

Any downsides to doing this sort of integration?

Aside from the revolting cost, the scarcity of service parts in the
field, and the limited range of frames that they will fit? Not
really, and with the exception of cost (which isn't an objection to
everyone), the issues are relatively trivial; I doubt that anyone is
going to try to retrofit a DA or Ultegra crank to an old bike with a
wierd BB shell, and the parts issue should be a moot point for most
riders for quite some time yet.

Quoted message said:

It would seem that if either the crankset or bottom bracket had
a problem, you would have to replace both.

Well, the bearings in these are serviced separately, so the most
common wear part can be replaced without trashing the whole assembly
(yes, the sprockets should wear out first, but that's not part of the
BB), so the main objection would seem to be that if the crank is
damaged, you may have to buy a complete assembly including a new BB.
(Presumably, the right-crank-and-shaft unit could be supplied
separately, but there is some suspicion that as a spare part, it might
cost more than the market price of a complete crank and BB assembly.)
Until such designs start appearing on bikes in the $600 class,
however, the added incremental cost of the BB in the assembly is not
going to present much of an objection; if you can afford the DA tax to
begin with, you can probably afford the added cost of the BB if you
manage to tear up the cranks.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

"Chris Esposito" asked:

Quoted message said:

Quoted message said:

A number of cranksets are advertising that they have integrated
bottom brackets, and list reduced weight and increased stiffness
as advantages of doing so. Do these claims hold? Are they really
lighter and stiffer than a pair of separate components?

Werehatrack answered:

Quoted message said:

Yes, they're stiffer than the typical previous designs used on road
bikes, and yes, they're lighter than most conventional BB and crank
assemblies.

Quoted message said:

Any downsides to doing this sort of integration?

Aside from the revolting cost,

Cost is related to other things than the bottom bracket type. Ever
since the failure of Positron and the success of Dura-Ace SIS, Shimano
has followed a "trickle-down" strategy, where new features are generally
introduced into the top of the line, then work their way down the line
as time goes by.

This system is not inherently expensive.

Quoted message said:

the scarcity of service parts in the
field,

Anything new and hot is gonna be scarce at first. One of the cool
things Shimano has done is that the bearing modules (one screws into
each side of the BB shell) are interchangeable all up and down the line
with other Hollowtech II. Same parts for Dura-Ace, Ultegra, Saint, Hone
so far, more to come no doubt.

Quoted message said:

and the limited range of frames that they will fit?

Not sure what you mean by that. They'll fit any ISO/English 68 mm BB
shell, and I believe they also do Italian thread, so pretty much any
bike made in the last 20 years can be fitted, aside from those which use
oddball proprietary shells, such as some older Gary Fishers, early
Merlins and the like.

Quoted message said:

...and with the exception of cost (which isn't an objection to
everyone), the issues are relatively trivial; I doubt that anyone is
going to try to retrofit a DA or Ultegra crank to an old bike with a
wierd BB shell, and the parts issue should be a moot point for most
riders for quite some time yet.

Quoted message said:

It would seem that if either the crankset or bottom bracket had
a problem, you would have to replace both.

Not at all.

Quoted message said:

Well, the bearings in these are serviced separately, so the most
common wear part can be replaced without trashing the whole assembly
(yes, the sprockets should wear out first, but that's not part of the
BB), so the main objection would seem to be that if the crank is
damaged, you may have to buy a complete assembly including a new BB.
(Presumably, the right-crank-and-shaft unit could be supplied
separately,

Right.

Quoted message said:

but there is some suspicion that as a spare part, it might
cost more than the market price of a complete crank and BB assembly.)

I doubt that.

Quoted message said:

Until such designs start appearing on bikes in the $600 class,
however, the added incremental cost of the BB in the assembly is not
going to present much of an objection; if you can afford the DA tax to
begin with, you can probably afford the added cost of the BB if you
manage to tear up the cranks.

Yep.

Sheldon "Give 'Em Time" Brown
+------------------------------------------------------------+
| "Shimano's policy was that ten percent of their work |
| force must be graduate engineers...By the mid-1970's, |
| Shimano probably had more people working on research and |
| development than all of their competitors combined... |
| the (1985) SIS Dura-Ace was the first computer-optimized |
| rear derailleur...In 1985, Shimano had about 40 percent
| of the U.S. market...By 1994, Shimano had more than 90 |
| percent of the U.S. market." |
| --Frank Berto: "The Dancing Chain" |
+------------------------------------------------------------+
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

Quoted message said:

Aside from the revolting cost,

They're ridiculously cheap! 😉

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7128029844

--
Phil, Squid-in-Training

On Thu, 03 Feb 2005 16:30:30 GMT, "Phil, Squid-in-Training"

may have said:

Quoted message said:

Aside from the revolting cost,

They're ridiculously cheap! 😉

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7128029844

Qty: 0 available.

The sale has ended.

(I think sombody forgot a little-bitty dot and a couple of round
things when they were putting in the starting bid price for that.)

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

"Sheldon Brown" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

"Chris Esposito" asked:

Quoted message said:

Quoted message said:

A number of cranksets are advertising that they have

integrated

Quoted message said:

Quoted message said:

Quoted message said:

bottom brackets, and list reduced weight and increased

stiffness

Quoted message said:

Quoted message said:

Quoted message said:

as advantages of doing so. Do these claims hold? Are they

really

Quoted message said:

Quoted message said:

Quoted message said:

lighter and stiffer than a pair of separate components?

Werehatrack answered:

Quoted message said:

Yes, they're stiffer than the typical previous designs used

on road

Quoted message said:

Quoted message said:

bikes, and yes, they're lighter than most conventional BB and

crank

Quoted message said:

Quoted message said:

assemblies.

Quoted message said:

Any downsides to doing this sort of integration?

Aside from the revolting cost,

Cost is related to other things than the bottom bracket type.

Ever

Quoted message said:

since the failure of Positron and the success of Dura-Ace SIS,

Shimano

Quoted message said:

has followed a "trickle-down" strategy, where new features are

generally

Quoted message said:

introduced into the top of the line, then work their way down

the line

Quoted message said:

as time goes by.

This system is not inherently expensive.

Quoted message said:

the scarcity of service parts in the
field,

Anything new and hot is gonna be scarce at first. One of the

cool

Quoted message said:

things Shimano has done is that the bearing modules (one screws

into

Quoted message said:

each side of the BB shell) are interchangeable all up and down

the line

Quoted message said:

with other Hollowtech II. Same parts for Dura-Ace, Ultegra,

Saint, Hone

Quoted message said:

so far, more to come no doubt.

Quoted message said:

and the limited range of frames that they will fit?

Not sure what you mean by that. They'll fit any ISO/English 68

mm BB

Quoted message said:

shell, and I believe they also do Italian thread, so pretty

much any

Quoted message said:

bike made in the last 20 years can be fitted, aside from those

which use

Quoted message said:

oddball proprietary shells, such as some older Gary Fishers,

early

Quoted message said:

Merlins and the like.

Quoted message said:

...and with the exception of cost (which isn't an objection

to

Quoted message said:

Quoted message said:

everyone), the issues are relatively trivial; I doubt that

anyone is

Quoted message said:

Quoted message said:

going to try to retrofit a DA or Ultegra crank to an old bike

with a

Quoted message said:

Quoted message said:

wierd BB shell, and the parts issue should be a moot point

for most

Quoted message said:

Quoted message said:

riders for quite some time yet.

Quoted message said:

It would seem that if either the crankset or bottom bracket

had

Quoted message said:

Quoted message said:

Quoted message said:

a problem, you would have to replace both.

Not at all.

Quoted message said:

Well, the bearings in these are serviced separately, so the

most

Quoted message said:

Quoted message said:

common wear part can be replaced without trashing the whole

assembly

Quoted message said:

Quoted message said:

(yes, the sprockets should wear out first, but that's not

part of the

Quoted message said:

Quoted message said:

BB), so the main objection would seem to be that if the crank

is

Quoted message said:

Quoted message said:

damaged, you may have to buy a complete assembly including a

new BB.

Quoted message said:

Quoted message said:

(Presumably, the right-crank-and-shaft unit could be supplied
separately,

Right.

Quoted message said:

but there is some suspicion that as a spare part, it might
cost more than the market price of a complete crank and BB

assembly.)

Quoted message said:

I doubt that.

Quoted message said:

Until such designs start appearing on bikes in the $600

class,

Quoted message said:

Quoted message said:

however, the added incremental cost of the BB in the assembly

is not

Quoted message said:

Quoted message said:

going to present much of an objection; if you can afford the

DA tax to

Quoted message said:

Quoted message said:

begin with, you can probably afford the added cost of the BB

if you

Quoted message said:

Quoted message said:

manage to tear up the cranks.

Yep.

If this means the end of conventional bottom brackets, I am going
to end up with a large box of useless cranks -- which I will have
to stack on my box of useless hubs, freewheels and non-indexing
derailleurs. -- Jay Beattie.

On Thu, 3 Feb 2005 14:56:42 -0800, "Jay Beattie"

may have said:

If this means the end of conventional bottom brackets, I am going
to end up with a large box of useless cranks -- which I will have
to stack on my box of useless hubs, freewheels and non-indexing
derailleurs. -- Jay Beattie.

The square taper will probably outlive all of us.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

"Werehatrack" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

On Thu, 03 Feb 2005 16:30:30 GMT, "Phil, Squid-in-Training"

may have said:

Quoted message said:

Aside from the revolting cost,

They're ridiculously cheap! 😉

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7128029844

Qty: 0 available.

The sale has ended.

(I think sombody forgot a little-bitty dot and a couple of round
things when they were putting in the starting bid price for that.)

Not to mention the 20-minute window for buying before the seller noticed...
How nice would that be to get a 2-piece carbon crankset/BB for $16? I'd
probably tell the seller that he or she has to sell it at that price because
it's a legally binding contract. 😉

--
Phil, Squid-in-Training

Chris Esposito said:

Are they really lighter and stiffer than a pair of separate

components?

Don't forget that the weight savings are fairly modest given the
radical redesign. For a DA crank and BB, you drop around 30-40 grams
from 7700 to 7800.

Jay Beattie said:

...
If this means the end of conventional bottom brackets, I am going
to end up with a large box of useless cranks....

Quit stuffing rec.bicycles.tech regulars in a box, Mr. Beattie!

--
Tom Sherman - Earth

If the marketing people have their way we'll have integrated bicycles
where everything is riveted together in one piece, and when the first
piece wears out, you discard the entire bicycle.

don't let them have their way !! BOYCOTT INTEGRATED COMPONENTRY !!!

- Don Gillies
San Diego, CA

Donald Gillies said:

If the marketing people have their way we'll have integrated bicycles
where everything is riveted together in one piece, and when the first
piece wears out, you discard the entire bicycle.

It's not just bicycles - it is EVERYTHING that is manufactured for
profit today!

Quoted message said:

don't let them have their way !! BOYCOTT INTEGRATED COMPONENTRY !!!

Oh, I wish we could

Brian

Sheldon answers-<< Sheldon "Give 'Em Time" Brown >><BR><BR>

Sorry Sheldon but another new 'standard' by shimano, that may or may not be
supported in the future?

How is this or SPD-R or Octalink or DA double only, or.....serve the cycling
public? How do things like the hollowtechII do anything but make things more
expensive and harder to service?

I look for something 'cycling' that actually helps to put more people on
bicycles and keep them there. shimano's new standard does not do that. It
answers no question, solves no problem. It is the stuff of marketing and
nothing else.

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

On 3 Feb 2005 21:13:44 -0800, [email hidden] (Donald Gillies)

Quoted message said:

If the marketing people have their way we'll have integrated bicycles
where everything is riveted together in one piece, and when the first
piece wears out, you discard the entire bicycle.

don't let them have their way !! BOYCOTT INTEGRATED COMPONENTRY !!!

- Don Gillies
San Diego, CA

Yeah, like this silly fork with INTEGRATED brakes!
http://www.mindspring.com/~heine/bikesite/bikesite/images/SINGERTRIALS.jpg
Probably not interchangeable with anything else, either.

Qui si parla Campagnolo said:

Sheldon answers-<< Sheldon "Give 'Em Time" Brown >><BR><BR>

Sorry Sheldon but another new 'standard' by shimano, that may or may not be
supported in the future?

How is this or SPD-R or Octalink or DA double only, or.....serve the cycling
public? How do things like the hollowtechII do anything but make things more
expensive and harder to service?

I look for something 'cycling' that actually helps to put more people on
bicycles and keep them there. shimano's new standard does not do that. It
answers no question, solves no problem. It is the stuff of marketing and
nothing else.

peter, with respect, new ideas & innovation are good. bad designs fail,
good ones survive. hence we have indexed shifting, 10 speeds, cassette
hubs, "compressionless" cable, bushingless chain, slanted parallelogram
derailleurs, clipless pedals... etc. i believe campy were late to
market in all the above innovations which have made both racing &
recreational cyclists lives much much better.

if integrated bb's turn out to be failures, so be it. if they
successfully address a design purpose of maximizing the performance of
their given materials, reduce weight & improve reliability [eg. where
traditional cranks regularly work loose because they're not assembled
correctly], _and_ they are accepted in their target markets, they will
survive. saying they "solve no problem" is like hearkening back to
carburettors & contact breaker ignition. a competent tech can set those
up to perform excellently, on & off the track, but reality is that
injection/electronic ignition are much more reliable in the real world
because they provide less scope for the unskilled to foul them up.
similarly, /you/ may never see a problem with tapered cranks because by
all accounts, you /are/ skilled & competent. my opinion, as "repairer
of last resort" for many many friends bikes that were serviced by
"reputable" [& expensive] lbs's, is that the vast majority of bike mechs
are neither, and the evidence is in the loose, broken, badly adjusted,
seized, scratched, stripped, torn, worn, dented, squeaky pieces of
garbage i have lying around my garage.

even ferrari have gotten reliable these days peter. time to move on.

Quoted message said:

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

Peter Chisholm said:

Sheldon answers-<< Sheldon "Give 'Em Time" Brown >><BR><BR>

Sorry Sheldon but another new 'standard' by shimano, that may or may not be
supported in the future?

How is this or SPD-R or Octalink or DA double only, or.....serve the cycling
public? How do things like the hollowtechII do anything but make things more
expensive and harder to service?

So, I guess you think Shimano should lay off all of their engineers and
shut down the R & D department, since the stuff they already make is
good enough? They can just keep pumping out the current designs ad nauseam?

That's the strategy that put Cyclo, Huret and Simplex where they are today!

Quoted message said:

I look for something 'cycling' that actually helps to put more people on
bicycles and keep them there.

Shimano is also seeking that, mainly with their Nexus and Nexave stuff.
If you're talking about putting "more people on bicycles" you're
talking about entry level stuff by definition.

Quoted message said:

shimano's new standard does not do that.

That's not what the high-end stuff is intended to do, it's not targeted
at beginners.

Quoted message said:

It answers no question, solves no problem. It is the stuff of marketing and
nothing else.

That's not true. It is lighter and easier to service. May also turn
out to be more durable...time will tell on that score.

Sheldon "Shimano Fan" Brown
+-------------------------------------------------+
| To stay young requires unceasing cultivation |
| of the ability to unlearn old falsehoods. |
| --Robert A. Heinlein |
+-------------------------------------------------+
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

"Qui si parla Campagnolo " <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

Sheldon answers-<< Sheldon "Give 'Em Time" Brown >><BR><BR>

Sorry Sheldon but another new 'standard' by shimano, that may

or may not be

Quoted message said:

supported in the future?

How is this or SPD-R or Octalink or DA double only,

or.....serve the cycling

Quoted message said:

public? How do things like the hollowtechII do anything but

make things more

Quoted message said:

expensive and harder to service?

I look for something 'cycling' that actually helps to put more

people on

Quoted message said:

bicycles and keep them there. shimano's new standard does not

do that. It

Quoted message said:

answers no question, solves no problem. It is the stuff of

marketing and

Quoted message said:

nothing else.

This design does appear to be an improvement over the standard
square-taper or even Octalink crank/BB interface. Not that
square taper was ever a problem for me, but it was for some -- as
you know from the frequent threads on this NG. -- Jay Beattie.