FSA SL cranks

On Sunday, May 23, 2021 at 12:58:00 PM UTC-7, Tom Kunich wrote:
On Sunday, May 23, 2021 at 12:43:55 PM UTC-7, jbeattie wrote:
On Sunday, May 23, 2021 at 10:41:10 AM UTC-7, AMuzi wrote:
On 5/23/2021 11:17 AM, jbeattie wrote:
On Sunday, May 23, 2021 at 8:26:24 AM UTC-7, wrote:
On Sunday, May 23, 2021 at 7:01:53 AM UTC-7, AMuzi wrote:
On 5/22/2021 5:13 PM, Tom Kunich wrote:
On Saturday, May 22, 2021 at 2:15:04 PM UTC-7, AMuzi wrote:
On 5/22/2021 2:37 PM, Tom Kunich wrote:
On Saturday, May 22, 2021 at 12:15:39 PM UTC-7, jbeattie wrote:
On Saturday, May 22, 2021 at 11:47:18 AM UTC-7, wrote:
On Saturday, May 22, 2021 at 9:04:08 AM UTC-7, jbeattie wrote:
On Saturday, May 22, 2021 at 7:59:15 AM UTC-7, AMuzi wrote:
On 5/22/2021 9:42 AM, Tom Kunich wrote:
I have an FSA SL crank and it has a shaft with 24 mm bearing surfaces. Now I don't know of any FSA bottom bracket with 24 mm shafts. MegaEvo is 30 mm if I understand them correct and MegaExo is 19 mm. Since I measured this with a micrometer I know that I can use Shimano bearing cups. But why would this have a shaft so dramatically different than the rest of the FSA stuff?

FSA says:

https://www.fullspeedahead.com/en/technology

(click the crankset image)

Further discussion:
https://accidentalrandonneur.wordpre...ga-bb86-crank/

from that page:
"All of Shimano’s Hollowtech II two-piece road bike
cranksets have a steel spindle 24 mm in diameter. The Omega
BB86 crank, very strangely, has a 19 mm spindle. You can see
both cranksets’ spindles and the difference between them. It
is this that makes the Omega BB86 crankset a bit of a
dead-end product..."
Luckily, the pedal-thread inserts on my FSA ISIS crank broke loose from the surrounding CF before the entire system went obsolete. What a piece of junk. I would criticize FSA for its multitude of standards, but after the demise of square drive, all the manufacturers cycled through a bunch of now-discarded standards. Praxis got a big chunk of the market making OE cranks for Specialized, and its cranks still have weird 28mm/30mm -- and SRAM has 22mm/24mm. It's hard to tell what is not a dead end product.
What I think is strange about this FSA SL crank is that it is 24 mm unless I'm making a conversion error - 0.9521 (two lowest digits i may not be remembering accurately)
Why is that strange? 24mm is the (or one of the) MegaExo standard. This is the BB you need. https://tinyurl.com/465769nf I wouldn't try using a Shimano since FSA used narrower bearings, and a Shimano BB may bind -- at least according to the interweb.

Well this all confuses me because Omega is a 19 mm shaft. Maybe I'm missing something there. Is the Omega a square taper or ISIS bearing?

I linked general information above. Here's the FSA technical
fro Omega:

https://shop.fullspeedahead.com/en/f...506.1621695207
--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971
OK, that says that the Omega is 19 mm.

So apparently MegaExo was different even though it looks the same. (or for that matter the MegaEvo)

And a regular Campagnolo UT crank is not a PT design.
Andrew, as far as I can tell the only difference is that PT uses different clearances in the PT cups. With an interference fit shaft of the power side and a interference fit in the cup of the non-power side. The UT has shaft interference fits on both sides. The Shimano uses interference fits in the cups on both sides. Is there any reason to chose one over the other? Or is it simply an engineering choice?

The Campagnolo design requires more tools, which is always a plus. The criticism of the much simpler Shimano design is that the slip-fit bearings can fret/wear the spindle, which doesn't happen with the press-fit bearings on he Campagnolo. As Lou said, the Campagnolo design is superior from an engineering standpoint.

I have not had a spindle fretting problem with Shimano cranks, but if I wore the spindle that badly, then I've probably worn the chainrings, too, and if I have to replace the chainrings, then might as well buy a crank.. If people want to whine and complain, they should whine and complain about chainring prices.

-- Jay Beattie.

[raises hand]
Been bitching for about 50 years now.

Cranksets are zero duty, chainrings are taxed as 'bicycle
parts'.
Which is odd because we have as many domestic crank manufacturers as we do chainring manufacturers. https://oldglorymtb.com/mountain-bik...de-in-america/ I wonder why we protect one and not the other.

It appears that the duty on chainrings is only 10% -- unless there is some China add-on that is not apparent from the harmonized tariff schedule. I should check Alibaba for knock-off.

-- Jay Beattie.
Well, a Dean titanium seatpost is $300 while the Chinese version which has a better seat attachment mechanism (to my mind) is $78.
And Yee Gods, the cost of American products seem to have absolutely no connection to reality. A Lightning crankset is about a grand of more than twice what a Campy costs. It does appear that the Lightning made every attempt to copy the Campy Record Ultra Torque except for the bearing interface. They use a lot cruder Herth central attachment.

On Sunday, May 23, 2021 at 11:51:04 AM UTC-7, Frank Krygowski wrote:
On 5/23/2021 11:21 AM, Tom Kunich wrote:
On Saturday, May 22, 2021 at 7:42:44 PM UTC-7, John B. wrote:
On Sat, 22 May 2021 11:47:16 -0700 (PDT), Tom Kunich
wrote:

On Saturday, May 22, 2021 at 9:04:08 AM UTC-7, jbeattie wrote:
On Saturday, May 22, 2021 at 7:59:15 AM UTC-7, AMuzi wrote:
On 5/22/2021 9:42 AM, Tom Kunich wrote:
I have an FSA SL crank and it has a shaft with 24 mm bearing surfaces. Now I don't know of any FSA bottom bracket with 24 mm shafts. MegaEvo is 30 mm if I understand them correct and MegaExo is 19 mm. Since I measured this with a micrometer I know that I can use Shimano bearing cups. But why would this have a shaft so dramatically different than the rest of the FSA stuff?

FSA says:

https://www.fullspeedahead.com/en/technology

(click the crankset image)

Further discussion:
https://accidentalrandonneur.wordpre...ga-bb86-crank/

from that page:
"All of Shimano’s Hollowtech II two-piece road bike
cranksets have a steel spindle 24 mm in diameter. The Omega
BB86 crank, very strangely, has a 19 mm spindle. You can see
both cranksets’ spindles and the difference between them. It
is this that makes the Omega BB86 crankset a bit of a
dead-end product..."
Luckily, the pedal-thread inserts on my FSA ISIS crank broke loose from the surrounding CF before the entire system went obsolete. What a piece of junk. I would criticize FSA for its multitude of standards, but after the demise of square drive, all the manufacturers cycled through a bunch of now-discarded standards. Praxis got a big chunk of the market making OE cranks for Specialized, and its cranks still have weird 28mm/30mm -- and SRAM has 22mm/24mm. It's hard to tell what is not a dead end product.

What I think is strange about this FSA SL crank is that it is 24 mm unless I'm making a conversion error - 0.9521 (two lowest digits i may not be remembering accurately)
0.94488189 I believe is the correct number
0.03937008" = 1 mm
Now we have some moron telling me what I measured with a micrometer. Tell us what the clearance is supposed to be to slide a shaft through a bearing moron.
Tom, you're wrong yet again. John is correct, yet again.

We have a moron who somehow doesn't remember that 1" is defined as
25.4mm. That's been the case since the 1950s, Tom. It's time you caught up.

By the way Frank, since looking at the cost of American made components I would probably like to talk to you about the designing some shift levers which we could prototype on a 3D printer. I have a somewhat unique design that initially could operate Shimano derailleurs. But it would require mechanical design that I'm not up to relearning. The levers could be set to shift 8..9,10 or 11 speed with a single small screw like the derailleur limit screws. By this time everyone knows my email is . In fact, too many people since 80% of my emails are asking for donations.

On Sunday, May 23, 2021 at 1:58:51 PM UTC-7, Tom Kunich wrote:
On Sunday, May 23, 2021 at 11:51:04 AM UTC-7, Frank Krygowski wrote:
On 5/23/2021 11:21 AM, Tom Kunich wrote:
On Saturday, May 22, 2021 at 7:42:44 PM UTC-7, John B. wrote:
On Sat, 22 May 2021 11:47:16 -0700 (PDT), Tom Kunich
wrote:

On Saturday, May 22, 2021 at 9:04:08 AM UTC-7, jbeattie wrote:
On Saturday, May 22, 2021 at 7:59:15 AM UTC-7, AMuzi wrote:
On 5/22/2021 9:42 AM, Tom Kunich wrote:
I have an FSA SL crank and it has a shaft with 24 mm bearing surfaces. Now I don't know of any FSA bottom bracket with 24 mm shafts. MegaEvo is 30 mm if I understand them correct and MegaExo is 19 mm. Since I measured this with a micrometer I know that I can use Shimano bearing cups. But why would this have a shaft so dramatically different than the rest of the FSA stuff?

FSA says:

https://www.fullspeedahead.com/en/technology

(click the crankset image)

Further discussion:
https://accidentalrandonneur.wordpre...ga-bb86-crank/

from that page:
"All of Shimano’s Hollowtech II two-piece road bike
cranksets have a steel spindle 24 mm in diameter. The Omega
BB86 crank, very strangely, has a 19 mm spindle. You can see
both cranksets’ spindles and the difference between them. It
is this that makes the Omega BB86 crankset a bit of a
dead-end product..."
Luckily, the pedal-thread inserts on my FSA ISIS crank broke loose from the surrounding CF before the entire system went obsolete. What a piece of junk. I would criticize FSA for its multitude of standards, but after the demise of square drive, all the manufacturers cycled through a bunch of now-discarded standards. Praxis got a big chunk of the market making OE cranks for Specialized, and its cranks still have weird 28mm/30mm -- and SRAM has 22mm/24mm. It's hard to tell what is not a dead end product.

What I think is strange about this FSA SL crank is that it is 24 mm unless I'm making a conversion error - 0.9521 (two lowest digits i may not be remembering accurately)
0.94488189 I believe is the correct number
0.03937008" = 1 mm
Now we have some moron telling me what I measured with a micrometer. Tell us what the clearance is supposed to be to slide a shaft through a bearing moron.
Tom, you're wrong yet again. John is correct, yet again.

We have a moron who somehow doesn't remember that 1" is defined as
25.4mm. That's been the case since the 1950s, Tom. It's time you caught up.
By the way Frank, since looking at the cost of American made components I would probably like to talk to you about the designing some shift levers which we could prototype on a 3D printer. I have a somewhat unique design that initially could operate Shimano derailleurs. But it would require mechanical design that I'm not up to relearning. The levers could be set to shift 8.9,10 or 11 speed with a single small screw like the derailleur limit screws. By this time everyone knows my email is . In fact, too many people since 80% of my emails are asking for donations.

After looking up Shimano road derailleur pull it would only work for 6-10 speed road derailleurs.

On Sun, 23 May 2021 08:21:29 -0700 (PDT), Tom Kunich
wrote:

Tell us what the clearance is supposed to be to slide a shaft through a bearing moron.

There's no single number that works for all bearing sizes.

First, you need to determine what type of fit you want per ISO 286.
https://www.engineersedge.com/manufacturing/preferred_mechanical_tolerances_metric_iso_286_131 66.htm

Next, you calculate the required clearance or interference fit for
your specific disaster in progress by using one of several online
calculators:
https://www.tribology-abc.com/calculators/e3_8.htm
https://www.gmnbt.com/shaft-housing-tolerance-calculator/
https://amesweb.info/press-fit/interference-fit-calculator.aspx
https://www.engineersedge.com/calculators/machine-design/press-fit/press-fit-calculator.htm
Mo
https://www.google.com/search?q=bearing+interference+fit+calculator
The hard part is finding all the required numbers. The bearing
manufacturers web pages and data sheets are usually required. If the
shaft "slides" through the bearing, it's probably too loose. If you
have to beat on it with a metal hammer or use an arbor press, it's
probably too tight. If you can tap it in place with a plastic hammer,
you win.

You could measure your shaft and bearing dimensions, but that doesn't
give you the manufacturers tolerances. I suggest you use the vendors
published min/max sizes and calculate the size required for your
desired fit.


--
Jeff Liebermann
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

On 5/23/2021 2:43 PM, jbeattie wrote:
On Sunday, May 23, 2021 at 10:41:10 AM UTC-7, AMuzi wrote:
On 5/23/2021 11:17 AM, jbeattie wrote:
On Sunday, May 23, 2021 at 8:26:24 AM UTC-7, wrote:
On Sunday, May 23, 2021 at 7:01:53 AM UTC-7, AMuzi wrote:
On 5/22/2021 5:13 PM, Tom Kunich wrote:
On Saturday, May 22, 2021 at 2:15:04 PM UTC-7, AMuzi wrote:
On 5/22/2021 2:37 PM, Tom Kunich wrote:
On Saturday, May 22, 2021 at 12:15:39 PM UTC-7, jbeattie wrote:
On Saturday, May 22, 2021 at 11:47:18 AM UTC-7, wrote:
On Saturday, May 22, 2021 at 9:04:08 AM UTC-7, jbeattie wrote:
On Saturday, May 22, 2021 at 7:59:15 AM UTC-7, AMuzi wrote:
On 5/22/2021 9:42 AM, Tom Kunich wrote:
I have an FSA SL crank and it has a shaft with 24 mm bearing surfaces. Now I don't know of any FSA bottom bracket with 24 mm shafts. MegaEvo is 30 mm if I understand them correct and MegaExo is 19 mm. Since I measured this with a micrometer I know that I can use Shimano bearing cups. But why would this have a shaft so dramatically different than the rest of the FSA stuff?

FSA says:

https://www.fullspeedahead.com/en/technology

(click the crankset image)

Further discussion:
https://accidentalrandonneur.wordpre...ga-bb86-crank/

from that page:
"All of Shimano’s Hollowtech II two-piece road bike
cranksets have a steel spindle 24 mm in diameter. The Omega
BB86 crank, very strangely, has a 19 mm spindle. You can see
both cranksets’ spindles and the difference between them. It
is this that makes the Omega BB86 crankset a bit of a
dead-end product..."
Luckily, the pedal-thread inserts on my FSA ISIS crank broke loose from the surrounding CF before the entire system went obsolete. What a piece of junk. I would criticize FSA for its multitude of standards, but after the demise of square drive, all the manufacturers cycled through a bunch of now-discarded standards. Praxis got a big chunk of the market making OE cranks for Specialized, and its cranks still have weird 28mm/30mm -- and SRAM has 22mm/24mm. It's hard to tell what is not a dead end product.
What I think is strange about this FSA SL crank is that it is 24 mm unless I'm making a conversion error - 0.9521 (two lowest digits i may not be remembering accurately)
Why is that strange? 24mm is the (or one of the) MegaExo standard. This is the BB you need. https://tinyurl.com/465769nf I wouldn't try using a Shimano since FSA used narrower bearings, and a Shimano BB may bind -- at least according to the interweb.

Well this all confuses me because Omega is a 19 mm shaft. Maybe I'm missing something there. Is the Omega a square taper or ISIS bearing?

I linked general information above. Here's the FSA technical
fro Omega:

https://shop.fullspeedahead.com/en/f...506.1621695207
--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971
OK, that says that the Omega is 19 mm.

So apparently MegaExo was different even though it looks the same. (or for that matter the MegaEvo)

And a regular Campagnolo UT crank is not a PT design.
Andrew, as far as I can tell the only difference is that PT uses different clearances in the PT cups. With an interference fit shaft of the power side and a interference fit in the cup of the non-power side. The UT has shaft interference fits on both sides. The Shimano uses interference fits in the cups on both sides. Is there any reason to chose one over the other? Or is it simply an engineering choice?

The Campagnolo design requires more tools, which is always a plus. The criticism of the much simpler Shimano design is that the slip-fit bearings can fret/wear the spindle, which doesn't happen with the press-fit bearings on he Campagnolo. As Lou said, the Campagnolo design is superior from an engineering standpoint.

I have not had a spindle fretting problem with Shimano cranks, but if I wore the spindle that badly, then I've probably worn the chainrings, too, and if I have to replace the chainrings, then might as well buy a crank. If people want to whine and complain, they should whine and complain about chainring prices.

-- Jay Beattie.

[raises hand]
Been bitching for about 50 years now.

Cranksets are zero duty, chainrings are taxed as 'bicycle
parts'.

Which is odd because we have as many domestic crank manufacturers as we do chainring manufacturers. https://oldglorymtb.com/mountain-bik...de-in-america/ I wonder why we protect one and not the other.

It appears that the duty on chainrings is only 10% -- unless there is some China add-on that is not apparent from the harmonized tariff schedule. I should check Alibaba for knock-off.

-- Jay Beattie.


Yes, 10%, used to be 14.5%

Which may not seem logical to normal people, but... Congress!

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

On Sunday, May 23, 2021 at 2:12:55 PM UTC-7, wrote:
On Sun, 23 May 2021 08:21:29 -0700 (PDT), Tom Kunich
wrote:

Tell us what the clearance is supposed to be to slide a shaft through a bearing moron.
There's no single number that works for all bearing sizes.

First, you need to determine what type of fit you want per ISO 286.
https://www.engineersedge.com/manufacturing/preferred_mechanical_tolerances_metric_iso_286_131 66.htm

Next, you calculate the required clearance or interference fit for
your specific disaster in progress by using one of several online
calculators:
https://www.tribology-abc.com/calculators/e3_8.htm
https://www.gmnbt.com/shaft-housing-tolerance-calculator/
https://amesweb.info/press-fit/interference-fit-calculator.aspx
https://www.engineersedge.com/calculators/machine-design/press-fit/press-fit-calculator.htm
Mo
https://www.google.com/search?q=bearing+interference+fit+calculator
The hard part is finding all the required numbers. The bearing
manufacturers web pages and data sheets are usually required. If the
shaft "slides" through the bearing, it's probably too loose. If you
have to beat on it with a metal hammer or use an arbor press, it's
probably too tight. If you can tap it in place with a plastic hammer,
you win.

You could measure your shaft and bearing dimensions, but that doesn't
give you the manufacturers tolerances. I suggest you use the vendors
published min/max sizes and calculate the size required for your
desired fit.
You should at least read you own citations. "The value of the diametrical interference is typically about δ/d=0.001"

On 5/23/2021 4:58 PM, Tom Kunich wrote:
On Sunday, May 23, 2021 at 11:51:04 AM UTC-7, Frank Krygowski wrote:
On 5/23/2021 11:21 AM, Tom Kunich wrote:
On Saturday, May 22, 2021 at 7:42:44 PM UTC-7, John B. wrote:
On Sat, 22 May 2021 11:47:16 -0700 (PDT), Tom Kunich
wrote:

On Saturday, May 22, 2021 at 9:04:08 AM UTC-7, jbeattie wrote:
On Saturday, May 22, 2021 at 7:59:15 AM UTC-7, AMuzi wrote:
On 5/22/2021 9:42 AM, Tom Kunich wrote:
I have an FSA SL crank and it has a shaft with 24 mm bearing surfaces. Now I don't know of any FSA bottom bracket with 24 mm shafts. MegaEvo is 30 mm if I understand them correct and MegaExo is 19 mm. Since I measured this with a micrometer I know that I can use Shimano bearing cups. But why would this have a shaft so dramatically different than the rest of the FSA stuff?

FSA says:

https://www.fullspeedahead.com/en/technology

(click the crankset image)

Further discussion:
https://accidentalrandonneur.wordpre...ga-bb86-crank/

from that page:
"All of Shimano’s Hollowtech II two-piece road bike
cranksets have a steel spindle 24 mm in diameter. The Omega
BB86 crank, very strangely, has a 19 mm spindle. You can see
both cranksets’ spindles and the difference between them. It
is this that makes the Omega BB86 crankset a bit of a
dead-end product..."
Luckily, the pedal-thread inserts on my FSA ISIS crank broke loose from the surrounding CF before the entire system went obsolete. What a piece of junk. I would criticize FSA for its multitude of standards, but after the demise of square drive, all the manufacturers cycled through a bunch of now-discarded standards. Praxis got a big chunk of the market making OE cranks for Specialized, and its cranks still have weird 28mm/30mm -- and SRAM has 22mm/24mm. It's hard to tell what is not a dead end product.

What I think is strange about this FSA SL crank is that it is 24 mm unless I'm making a conversion error - 0.9521 (two lowest digits i may not be remembering accurately)
0.94488189 I believe is the correct number
0.03937008" = 1 mm
Now we have some moron telling me what I measured with a micrometer. Tell us what the clearance is supposed to be to slide a shaft through a bearing moron.
Tom, you're wrong yet again. John is correct, yet again.

We have a moron who somehow doesn't remember that 1" is defined as
25.4mm. That's been the case since the 1950s, Tom. It's time you caught up.

By the way Frank, since looking at the cost of American made components I would probably like to talk to you about the designing some shift levers which we could prototype on a 3D printer. I have a somewhat unique design that initially could operate Shimano derailleurs. But it would require mechanical design that I'm not up to relearning. The levers could be set to shift 8.9,10 or 11 speed with a single small screw like the derailleur limit screws. By this time everyone knows my email is . In fact, too many people since 80% of my emails are asking for donations.

I'm not interested in the project. But given your reputation here, I'm
sure you'll soon have dozens of engineers asking to work with you! Good
luck!

--
- Frank Krygowski

On Sun, 23 May 2021 14:50:57 -0400, Frank Krygowski
wrote:

On 5/23/2021 11:21 AM, Tom Kunich wrote:
On Saturday, May 22, 2021 at 7:42:44 PM UTC-7, John B. wrote:
On Sat, 22 May 2021 11:47:16 -0700 (PDT), Tom Kunich
wrote:

On Saturday, May 22, 2021 at 9:04:08 AM UTC-7, jbeattie wrote:
On Saturday, May 22, 2021 at 7:59:15 AM UTC-7, AMuzi wrote:
On 5/22/2021 9:42 AM, Tom Kunich wrote:
I have an FSA SL crank and it has a shaft with 24 mm bearing surfaces. Now I don't know of any FSA bottom bracket with 24 mm shafts. MegaEvo is 30 mm if I understand them correct and MegaExo is 19 mm. Since I measured this with a micrometer I know that I can use Shimano bearing cups. But why would this have a shaft so dramatically different than the rest of the FSA stuff?

FSA says:

https://www.fullspeedahead.com/en/technology

(click the crankset image)

Further discussion:
https://accidentalrandonneur.wordpre...ga-bb86-crank/

from that page:
"All of Shimano’s Hollowtech II two-piece road bike
cranksets have a steel spindle 24 mm in diameter. The Omega
BB86 crank, very strangely, has a 19 mm spindle. You can see
both cranksets’ spindles and the difference between them. It
is this that makes the Omega BB86 crankset a bit of a
dead-end product..."
Luckily, the pedal-thread inserts on my FSA ISIS crank broke loose from the surrounding CF before the entire system went obsolete. What a piece of junk. I would criticize FSA for its multitude of standards, but after the demise of square drive, all the manufacturers cycled through a bunch of now-discarded standards. Praxis got a big chunk of the market making OE cranks for Specialized, and its cranks still have weird 28mm/30mm -- and SRAM has 22mm/24mm. It's hard to tell what is not a dead end product.

What I think is strange about this FSA SL crank is that it is 24 mm unless I'm making a conversion error - 0.9521 (two lowest digits i may not be remembering accurately)
0.94488189 I believe is the correct number
0.03937008" = 1 mm
Now we have some moron telling me what I measured with a micrometer. Tell us what the clearance is supposed to be to slide a shaft through a bearing moron.

Tom, you're wrong yet again. John is correct, yet again.

We have a moron who somehow doesn't remember that 1" is defined as
25.4mm. That's been the case since the 1950s, Tom. It's time you caught up.

Lord! It is so grand to be so right, all the time...

(or perhaps to be more exact, take the time to look up the correct
answer before commenting :-)
--
Cheers,

John B.

On Sun, 23 May 2021 08:21:29 -0700 (PDT), Tom Kunich
wrote:

On Saturday, May 22, 2021 at 7:42:44 PM UTC-7, John B. wrote:
On Sat, 22 May 2021 11:47:16 -0700 (PDT), Tom Kunich
wrote:

On Saturday, May 22, 2021 at 9:04:08 AM UTC-7, jbeattie wrote:
On Saturday, May 22, 2021 at 7:59:15 AM UTC-7, AMuzi wrote:
On 5/22/2021 9:42 AM, Tom Kunich wrote:
I have an FSA SL crank and it has a shaft with 24 mm bearing surfaces. Now I don't know of any FSA bottom bracket with 24 mm shafts. MegaEvo is 30 mm if I understand them correct and MegaExo is 19 mm. Since I measured this with a micrometer I know that I can use Shimano bearing cups. But why would this have a shaft so dramatically different than the rest of the FSA stuff?

FSA says:

https://www.fullspeedahead.com/en/technology

(click the crankset image)

Further discussion:
https://accidentalrandonneur.wordpre...ga-bb86-crank/

from that page:
"All of Shimano’s Hollowtech II two-piece road bike
cranksets have a steel spindle 24 mm in diameter. The Omega
BB86 crank, very strangely, has a 19 mm spindle. You can see
both cranksets’ spindles and the difference between them. It
is this that makes the Omega BB86 crankset a bit of a
dead-end product..."
Luckily, the pedal-thread inserts on my FSA ISIS crank broke loose from the surrounding CF before the entire system went obsolete. What a piece of junk. I would criticize FSA for its multitude of standards, but after the demise of square drive, all the manufacturers cycled through a bunch of now-discarded standards. Praxis got a big chunk of the market making OE cranks for Specialized, and its cranks still have weird 28mm/30mm -- and SRAM has 22mm/24mm. It's hard to tell what is not a dead end product.

What I think is strange about this FSA SL crank is that it is 24 mm unless I'm making a conversion error - 0.9521 (two lowest digits i may not be remembering accurately)
0.94488189 I believe is the correct number
0.03937008" = 1 mm
Now we have some moron telling me what I measured with a micrometer. Tell us what the clearance is supposed to be to slide a shaft through a bearing moron.

Tommy you said "it is 24 mm unless I'm making a conversion error -
0.9521" I simply pointed out that 0.9521 is not 24mm.

As to clearance to slide a shaft into a bearing, well, it is sort of
"whatever you want" within some limits. I've seen some shafts sized
so that the could be pushed into the bearing by hand and I've seen
some that required a press to mount.
--
Cheers,

John B.

On Sun, 23 May 2021 12:17:44 -0700 (PDT), Tom Kunich
wrote:

On Sunday, May 23, 2021 at 11:51:04 AM UTC-7, Frank Krygowski wrote:
On 5/23/2021 11:21 AM, Tom Kunich wrote:
On Saturday, May 22, 2021 at 7:42:44 PM UTC-7, John B. wrote:
On Sat, 22 May 2021 11:47:16 -0700 (PDT), Tom Kunich
wrote:

On Saturday, May 22, 2021 at 9:04:08 AM UTC-7, jbeattie wrote:
On Saturday, May 22, 2021 at 7:59:15 AM UTC-7, AMuzi wrote:
On 5/22/2021 9:42 AM, Tom Kunich wrote:
I have an FSA SL crank and it has a shaft with 24 mm bearing surfaces. Now I don't know of any FSA bottom bracket with 24 mm shafts. MegaEvo is 30 mm if I understand them correct and MegaExo is 19 mm. Since I measured this with a micrometer I know that I can use Shimano bearing cups. But why would this have a shaft so dramatically different than the rest of the FSA stuff?

FSA says:

https://www.fullspeedahead.com/en/technology

(click the crankset image)

Further discussion:
https://accidentalrandonneur.wordpre...ga-bb86-crank/

from that page:
"All of Shimano’s Hollowtech II two-piece road bike
cranksets have a steel spindle 24 mm in diameter. The Omega
BB86 crank, very strangely, has a 19 mm spindle. You can see
both cranksets’ spindles and the difference between them. It
is this that makes the Omega BB86 crankset a bit of a
dead-end product..."
Luckily, the pedal-thread inserts on my FSA ISIS crank broke loose from the surrounding CF before the entire system went obsolete. What a piece of junk. I would criticize FSA for its multitude of standards, but after the demise of square drive, all the manufacturers cycled through a bunch of now-discarded standards. Praxis got a big chunk of the market making OE cranks for Specialized, and its cranks still have weird 28mm/30mm -- and SRAM has 22mm/24mm. It's hard to tell what is not a dead end product.

What I think is strange about this FSA SL crank is that it is 24 mm unless I'm making a conversion error - 0.9521 (two lowest digits i may not be remembering accurately)
0.94488189 I believe is the correct number
0.03937008" = 1 mm
Now we have some moron telling me what I measured with a micrometer. Tell us what the clearance is supposed to be to slide a shaft through a bearing moron.
Tom, you're wrong yet again. John is correct, yet again.

We have a moron who somehow doesn't remember that 1" is defined as
25.4mm. That's been the case since the 1950s, Tom. It's time you caught up.

Frank, do you even have a clue what is being said? Explain to me what the measurement of 1" in the metric units has to do with the ****ing conversation you moronic ass?

I was MEASURING the shaft of the FSA SL crankset and it measured 24 mm with a little clearance. So explain to everyone here why you are making your usual ****ing preposterous statements and pretending as if John is even smarter than you are. Indeed, it appears that John IS smarter than you are since you don't even know what the conversation was about and John was repeating his usual hyperbole.

" it measured 24 mm with a little clearance."

That is probably the stupidest statement I ever heard anyone who
purports to be a mechanic say. If you measure something then you
measure it. What you are doing is saying, "well, it isn't really 24 mm
but I'll just call it that."
--
Cheers,

John B.