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Hypothetical question: 32 hole hub, 16 hole rim(6 posts)

Hypothetical question: 32 hole hub, 16 hole rimwilsonc
Nov 3, 2002 8:41 PM
Hypothetically, if a front wheel like this were to be built with 16 spokes radial laced, then the drillings of the hub dont line up correctly. Therefore, onced laced up, one flange would be 'twisting' against the other flange. Is this a problem (assuming a strong rim and hub)? Have people built wheels up like this, and what are your experiences? How do you calculate spoke length?

and what about 2 cross and 3 cross?

thanks,
wilson
re: Hypothetical question: 32 hole hub, 16 hole rimGregR
Nov 4, 2002 4:10 AM
No, as long as one skips a flange hole between spokes, everything will line up. Spoke legnth calculation is the same as you would do for other wheels.

The only twisting going on is in the logic of the person who decideds to build a wheel like this. The disadvantages heavily outweigh the advantages (unless of course, you really do like the taste of pavement).

G
I'm pretty sure that everything wont line upwilsonc
Nov 4, 2002 6:14 AM
I'm not convinced that everthing will line up correctly. Here is why:

Imagine a hub drilled for 8 spokes (this is just for illustration) and you wanted to lace it up with 4 spokes. Put the hub in a position where the
Left flange has holes at 0, 90, 180, and 270 degrees
Right flange has holes at 45, 135, 225, 315

Lets say you skipped every other hole on the hub. well, that would leave holes at
Left flange using holes at 0, 180 degrees
Right flange using holes at 45 and 225 degrees, or 135 and 315.

Well this isnt 'lined up' because you would want the right flange to use holes at 90 and 180, but there arent holes on the right side drilled for that.

Now, this effect is less pronounced with a higher spoke count, but it is still present.

I will take your advice and not build a wheel without matching rim, hub drill counts. I just had some spare parts and was considering building one.

wilson
I see what you mean...but...GregR
Nov 4, 2002 4:51 PM
The spoke hole offset in opposing hub flanges is for facilitation of inserting the spokes and is determined by the spoke hole and flange diameter. Not an arbitrary 50%. On low flange hubs, it may be centered between the holes on the opposite flange, but that is because of necessity rather than a calculation.

If you look closely at a high flange hub, you will notice that the offset is about the diamteter of the spoke head itself.

G
re: Hypothetical question: 32 hole hub, 16 hole rimFilm No More
Nov 4, 2002 5:24 AM
Back in the day before Rolfs, I raced (tri's) on a 36 hole rim and hub laced with 18 bladed spokes. I still recall how the front wheel used to do some strange things while cruising down the hill at 40mph.

Ahh, now that I am older and a bit wiser, I gotta agree with Greg, don't do it.

Save some money and buy some wheels designed to for the purpose.
Well, the holes WILL line up, but...brider
Nov 4, 2002 9:55 AM
it's still not something I'd want to do. Radial laced is a fairly easy build, but having all those open holes on a radial lacing just gives me the willies. The problem really is that you're placing a lot of radial load (spoke tension needs to be higher than if it were laced 32) on relatively little material at the hub. If you DO decide to go with this, check the hub often for cracks coming out of the spoke holes, even if you're a lightweight. It's not YOUR weight that really determines the fatigue on the hub, it's the spoke tension.

I've got a 36 hole hub that I laced to a 32 hole rim. Open holes at 90 and 270 on one side, 0 and 180 on the other. Works fine.