Track cranks/bb question - Page 2 - Cycling Mob: Road Cycling, Mountain Biking and More

08-05-2004, 10:19 PM

On 5 Aug 2004 13:59:58 -0700, [Only registered and activated users can see links. ] (supabonbon)
wrote:

>What is the major difference between track cranks and regular road
>cranks when it comes to chainline issues? I know the spindle length of
>the bb is typically shorter, and it seems like track cranks typically
>have a larger chainwheel diameter. And maybe track cranks are a little
>more built-up.

Contemporary track cranks generally conform to the common chainline
standard of 42.5 mm., plus or minus .5 mm. It's a specification shared
with premium track hub models for compatibility.

As part of our online track catalogue, there's a reference page that
addresses many track-specific issues, including chainline, which you
may find helpful. The link direct to the page is
[Only registered and activated users can see links. ]

-------------------------------
John Dacey
Business Cycles, Miami, Florida
[Only registered and activated users can see links. ]
Since 1983
Our catalog of track equipment: online since 1996
-------------------------------

08-06-2004, 12:15 AM

Sheldon Brown <[Only registered and activated users can see links. ]> writes:

> supabonbon wrote:
>
> > What is the major difference between track cranks and regular road
> > cranks when it comes to chainline issues?
>
> Track cranks generally have about a 42 mm chainline, sometimes a bit
> less. See: [Only registered and activated users can see links. ]
>

Does it make sense to speak of chainline for a crank alone?
I had thought that it really only made sense for a BB and crank
combination. At least for square taper cranks, whose BBs are
available in so many sizes that one can adapt them to most any
chainline. Or am I missing something?

08-06-2004, 12:15 AM

Sheldon Brown <[Only registered and activated users can see links. ]> writes:

> supabonbon wrote:
>
> > What is the major difference between track cranks and regular road
> > cranks when it comes to chainline issues?
>
> Track cranks generally have about a 42 mm chainline, sometimes a bit
> less. See: [Only registered and activated users can see links. ]
>

Does it make sense to speak of chainline for a crank alone?
I had thought that it really only made sense for a BB and crank
combination. At least for square taper cranks, whose BBs are
available in so many sizes that one can adapt them to most any
chainline. Or am I missing something?

08-06-2004, 12:15 AM

Sheldon Brown <[Only registered and activated users can see links. ]> writes:

> supabonbon wrote:
>
> > What is the major difference between track cranks and regular road
> > cranks when it comes to chainline issues?
>
> Track cranks generally have about a 42 mm chainline, sometimes a bit
> less. See: [Only registered and activated users can see links. ]
>

Does it make sense to speak of chainline for a crank alone?
I had thought that it really only made sense for a BB and crank
combination. At least for square taper cranks, whose BBs are
available in so many sizes that one can adapt them to most any
chainline. Or am I missing something?

08-06-2004, 12:15 AM

Sheldon Brown <[Only registered and activated users can see links. ]> writes:

> supabonbon wrote:
>
> > What is the major difference between track cranks and regular road
> > cranks when it comes to chainline issues?
>
> Track cranks generally have about a 42 mm chainline, sometimes a bit
> less. See: [Only registered and activated users can see links. ]
>

Does it make sense to speak of chainline for a crank alone?
I had thought that it really only made sense for a BB and crank
combination. At least for square taper cranks, whose BBs are
available in so many sizes that one can adapt them to most any
chainline. Or am I missing something?

08-06-2004, 12:15 AM

Sheldon Brown <[Only registered and activated users can see links. ]> writes:

> supabonbon wrote:
>
> > What is the major difference between track cranks and regular road
> > cranks when it comes to chainline issues?
>
> Track cranks generally have about a 42 mm chainline, sometimes a bit
> less. See: [Only registered and activated users can see links. ]
>

Does it make sense to speak of chainline for a crank alone?
I had thought that it really only made sense for a BB and crank
combination. At least for square taper cranks, whose BBs are
available in so many sizes that one can adapt them to most any
chainline. Or am I missing something?

08-06-2004, 09:27 AM

supabonbon wrote:
>>
>>>What is the major difference between track cranks and regular road
>>>cranks when it comes to chainline issues?

I replied, in part:

>>Track cranks generally have about a 42 mm chainline, sometimes a bit
>>less. See: [Only registered and activated users can see links. ]
>>
Jim Smith wrote:
>
> Does it make sense to speak of chainline for a crank alone?
> I had thought that it really only made sense for a BB and crank
> combination. At least for square taper cranks, whose BBs are
> available in so many sizes that one can adapt them to most any
> chainline. Or am I missing something?

My assumption was that the mysterious "supabonbon" was referring to
standard installations, where the manufacturer's recommended bottom
bracket would be used.

Otherwise, the original question would have been meaningless.

Indeed, if you mix and match bottom brackets, you can do all kinds of
non-standard things with chainline.

Sheldon "http://sheldonbrown.com/chainline" Brown
+--------------------------------------------------------+
| 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 |
+--------------------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
[Only registered and activated users can see links. ]
Hard-to-find parts shipped Worldwide
[Only registered and activated users can see links. ] [Only registered and activated users can see links. ]

08-06-2004, 09:27 AM

supabonbon wrote:
>>
>>>What is the major difference between track cranks and regular road
>>>cranks when it comes to chainline issues?

I replied, in part:

>>Track cranks generally have about a 42 mm chainline, sometimes a bit
>>less. See: [Only registered and activated users can see links. ]
>>
Jim Smith wrote:
>
> Does it make sense to speak of chainline for a crank alone?
> I had thought that it really only made sense for a BB and crank
> combination. At least for square taper cranks, whose BBs are
> available in so many sizes that one can adapt them to most any
> chainline. Or am I missing something?

My assumption was that the mysterious "supabonbon" was referring to
standard installations, where the manufacturer's recommended bottom
bracket would be used.

Otherwise, the original question would have been meaningless.

Indeed, if you mix and match bottom brackets, you can do all kinds of
non-standard things with chainline.

Sheldon "http://sheldonbrown.com/chainline" Brown
+--------------------------------------------------------+
| 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 |
+--------------------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
[Only registered and activated users can see links. ]
Hard-to-find parts shipped Worldwide
[Only registered and activated users can see links. ] [Only registered and activated users can see links. ]

08-06-2004, 09:27 AM

supabonbon wrote:
>>
>>>What is the major difference between track cranks and regular road
>>>cranks when it comes to chainline issues?

I replied, in part:

>>Track cranks generally have about a 42 mm chainline, sometimes a bit
>>less. See: [Only registered and activated users can see links. ]
>>
Jim Smith wrote:
>
> Does it make sense to speak of chainline for a crank alone?
> I had thought that it really only made sense for a BB and crank
> combination. At least for square taper cranks, whose BBs are
> available in so many sizes that one can adapt them to most any
> chainline. Or am I missing something?

My assumption was that the mysterious "supabonbon" was referring to
standard installations, where the manufacturer's recommended bottom
bracket would be used.

Otherwise, the original question would have been meaningless.

Indeed, if you mix and match bottom brackets, you can do all kinds of
non-standard things with chainline.

Sheldon "http://sheldonbrown.com/chainline" Brown
+--------------------------------------------------------+
| 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 |
+--------------------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
[Only registered and activated users can see links. ]
Hard-to-find parts shipped Worldwide
[Only registered and activated users can see links. ] [Only registered and activated users can see links. ]

08-06-2004, 09:27 AM

supabonbon wrote:
>>
>>>What is the major difference between track cranks and regular road
>>>cranks when it comes to chainline issues?

I replied, in part:

>>Track cranks generally have about a 42 mm chainline, sometimes a bit
>>less. See: [Only registered and activated users can see links. ]
>>
Jim Smith wrote:
>
> Does it make sense to speak of chainline for a crank alone?
> I had thought that it really only made sense for a BB and crank
> combination. At least for square taper cranks, whose BBs are
> available in so many sizes that one can adapt them to most any
> chainline. Or am I missing something?

My assumption was that the mysterious "supabonbon" was referring to
standard installations, where the manufacturer's recommended bottom
bracket would be used.

Otherwise, the original question would have been meaningless.

Indeed, if you mix and match bottom brackets, you can do all kinds of
non-standard things with chainline.

Sheldon "http://sheldonbrown.com/chainline" Brown
+--------------------------------------------------------+
| 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 |
+--------------------------------------------------------+
Harris Cyclery, West Newton, Massachusetts
Phone 617-244-9772 FAX 617-244-1041
[Only registered and activated users can see links. ]
Hard-to-find parts shipped Worldwide
[Only registered and activated users can see links. ] [Only registered and activated users can see links. ]