Misaligned eyelets

[Frank]

Misaligned eyelets

I'm building a set of wheels with Bontrager Mustang Rims (all parts new). For the rear wheel I'm
using the OSB (Offset spoke bed) version. I have a problem getting this wheel true with an even
spoke tension. Upon a closer investigation I found that the eyelets are not aligned properly. For
the drive side I found the eyelets vary within .8mm measured from one side of the rim. The non-drive
side varies about .6mm.

If I keep an even spoke tension the rim is almost 2mm out of lateral true. To bring the lateral true
within a half a mm. I need to loosen some spokes one full turn while the two spokes next to need an
extra half turn.

I started over twice to see if I could do any better but the results are the same.

I already exchanged the rim for another one once but the new one is no different. My question is,
what is an acceptable tolerance for the variation of the eyelets? Would you accept this rim and live
with a more uneven spoke tension?

The front wheel with a symmetrical rim has perfectly aligned eyelets and came out perfectly true.

Thank you for your reply Frank

 

[David Kunz]

Frank wrote:
> Misaligned eyelets
>
> I'm building a set of wheels with Bontrager Mustang Rims (all parts new). For the rear wheel I'm
> using the OSB (Offset spoke bed) version. I have a problem getting this wheel true with an even
> spoke tension. Upon a closer investigation I found that the eyelets are not aligned properly. For
> the drive side I found the eyelets vary within .8mm measured from one side of the rim. The
> non-drive side varies about .6mm.
>
> If I keep an even spoke tension the rim is almost 2mm out of lateral true. To bring the lateral
> true within a half a mm. I need to loosen some spokes one full turn while the two spokes next to
> need an extra half turn.
>
> I started over twice to see if I could do any better but the results are the same.
>
> I already exchanged the rim for another one once but the new one is no different. My question is,
> what is an acceptable tolerance for the variation of the eyelets? Would you accept this rim and
> live with a more uneven spoke tension?
>
> The front wheel with a symmetrical rim has perfectly aligned eyelets and came out perfectly true.
>
> Thank you for your reply Frank

I built 2 wheels recently using that rim and had no problems.

Are you sure that you have the correct side in the correct spoke holes? Are you sure that you're
balancing the spoke tension (spokes contribute to trueness from many spokes away from the out of
true spot).

David

 

[Nigel Grinter]

[email protected] (Frank) wrote in message news:<[email protected]>...
> Misaligned eyelets
>
> I'm building a set of wheels with Bontrager Mustang Rims (all parts new). For the rear wheel I'm
> using the OSB (Offset spoke bed) version. I have a problem getting this wheel true with an even
> spoke tension. Upon a closer investigation I found that the eyelets are not aligned properly. For
> the drive side I found the eyelets vary within .8mm measured from one side of the rim. The
> non-drive side varies about .6mm.
>
> If I keep an even spoke tension the rim is almost 2mm out of lateral true. To bring the lateral
> true within a half a mm. I need to loosen some spokes one full turn while the two spokes next to
> need an extra half turn.
>
> I started over twice to see if I could do any better but the results are the same.
>
> I already exchanged the rim for another one once but the new one is no different. My question is,
> what is an acceptable tolerance for the variation of the eyelets? Would you accept this rim and
> live with a more uneven spoke tension?
>
> The front wheel with a symmetrical rim has perfectly aligned eyelets and came out perfectly true.
>
> Thank you for your reply Frank

I very much doubt that the alignment variation is the cause of your troubles. If you read 'The
Bicycle Wheel' by Jobst Brandt, he tells how to achieve even spoke tension after you have laterally
and radially trued the wheel. Basically, you loosen a tight spoke and tighten the two spokes on
either side of it (the two on the same side of the wheel as the tight one). Vice versa with a loose
spoke. This allows the tensions to be equalized without much affecting lateral trueness. Don't
expect to get it absolutely perfect, but the spokes should not sound very different when plucked (or
not differ by more than 5-10% when measured with a tensionmeter).

Nigel Grinter

 

[Frank]

David Kunz <[email protected]> wrote in message
news:<[email protected]>...
>
> I built 2 wheels recently using that rim and had no problems.
>
> Are you sure that you have the correct side in the correct spoke holes?

Yes, I checked this more than once.

> Are you sure that you're balancing the spoke tension (spokes contribute to trueness from many
> spokes away from the out of true spot).

I may not do this right. I guess I need to get Jobst wheel book. I have been using Sheldon Browns
guide lines for several wheels and never had any problems.

My point is really if the .8mm variation in eyelets is something you should be able to work around.

>
> David

Thanks