CXP21 Effective Rim Diameter



Status
Not open for further replies.
A

Andrew Martin

Guest
Hey all - just wanted to see if any of you had access to the Wheelsmith builders guide that might
have the ERD for the CXP21 rim. I'm trying to replace a velocity Aerohead that's a 601mm. They look
rather close in design.

From http://www.branfordbike.com/wheels/wheel1.html:

For spoke calculation purposes, the effective rim diameter (ERD) is 601 mm.

The CXP33 is 596mm, so I'm hoping it's close (by my math (596 + ((33x2) - (31x2) ) = 600?). I
assume that a diameter difference of 1 mil is good enough? I've always been told that +/- 1mm
isn't an issue.

Any input is appreciated.

Thanks - a (note - being a cheap ******* here and don't want to fork out $60 for a Velocity when I
can get a CXP31 for $20).
 
Andrew Martin wrote:
>
> Hey all - just wanted to see if any of you had access to the Wheelsmith builders guide that might
> have the ERD for the CXP21 rim. I'm trying to replace a velocity Aerohead that's a 601mm. They
> look rather close in design.
>
> From http://www.branfordbike.com/wheels/wheel1.html:
>
> For spoke calculation purposes, the effective rim diameter (ERD) is 601 mm.
>
> The CXP33 is 596mm, so I'm hoping it's close (by my math (596 + ((33x2) - (31x2) ) = 600?). I
> assume that a diameter difference of 1 mil is good enough? I've always been told that +/- 1mm
> isn't an issue.
>
> Any input is appreciated.
>
> Thanks - a (note - being a cheap ******* here and don't want to fork out $60 for a Velocity when I
> can get a CXP31 for $20).

http://www.tech-mavic.com/uk/sources/Produits/ROUTE/Jantes/99RoadRimRange/ClincherRoadRim99.pdf

There it is listed as 598.5 mm.
 
I believe that both the CXP21 and newer Aerohead rims have ERD of 602. You should be fine.

On 17 Feb 2003 17:36:03 -0800, [email protected] (Andrew Martin) wrote:

>Hey all - just wanted to see if any of you had access to the Wheelsmith builders guide that might
>have the ERD for the CXP21 rim. I'm trying to replace a velocity Aerohead that's a 601mm. They look
>rather close in design.
 
"Andrew Martin" <[email protected]> wrote in message
news:[email protected]...
> Hey all - just wanted to see if any of you had access to the Wheelsmith builders guide that might
> have the ERD for the CXP21 rim. I'm trying to replace a velocity Aerohead that's a 601mm. They
> look rather close in design.
>
> From http://www.branfordbike.com/wheels/wheel1.html:
>
> For spoke calculation purposes, the effective rim diameter (ERD) is 601 mm.
>
> The CXP33 is 596mm, so I'm hoping it's close (by my math (596 + ((33x2) - (31x2) ) = 600?). I
> assume that a diameter difference of 1 mil is good enough? I've always been told that +/- 1mm
> isn't an issue.
>
> Any input is appreciated.
>
> Thanks - a (note - being a cheap ******* here and don't want to fork out $60 for a Velocity when I
> can get a CXP31 for $20).

This site: http://www.fa-technik.adfc.de/Komponenten/Felge/Felge622.html (an excellent one to
bookmark) gives it as 601.5.
 
Paul Kopit <[email protected]> wrote in message
news:<[email protected]>...
> I believe that both the CXP21 and newer Aerohead rims have ERD of 602. You should be fine.
>
> On 17 Feb 2003 17:36:03 -0800, [email protected] (Andrew Martin) wrote:
>
> >Hey all - just wanted to see if any of you had access to the Wheelsmith builders guide that might
> >have the ERD for the CXP21 rim. I'm trying to replace a velocity Aerohead that's a 601mm. They
> >look rather close in design.

After some more searching on sheldon's page (should have started there, not google) I found
references with all the ERD's. Looks like I'm in the right ballpark - thanks for your help.

Spoke Calculators with Common Hub and Rim data (Effective Rim Diameter)
http://www.sheldonbrown.com/wheelbuild.html#length
 
Status
Not open for further replies.

Similar threads

A
Replies
1
Views
626
D
A
Replies
0
Views
1K
A