Bicycle Mechanics - Tamden front wheel: 40 hole, lacing four cross not ok?

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Batavus
11-06-07, 02:03 PM
I've just completed the above mentioned build. It's a 40 hole XT tandem hub to Velocity Fusion using Dt Swiss db spokes. It is for a racing-style tandem. I laced it four cross because we didn't have the length for three cross in stock. Now someone has mentioned that would be a bad idea, since the four cross lacing makes the wheel weaker laterally and with the extra forces involved, seeing as this will be a racing tandem, the wheel could buckle. At least sooner than were it a three cross lacing.

What do you think?

Ps excuse the typo in the thread title


zonatandem
11-06-07, 02:13 PM
With 40 spokes . . . don't think it will buckle.
But a racing tandem with 40 spoke front wheel? Heck, we don't race and use 32 spokes up front . . .
Rijd te Zamen!
Rudy and Kay/zonatandem

urbanknight
11-06-07, 02:25 PM
4x should be fine. Whoever told you it would buckle must not have seen any velodrome track sprints in the 70s or 80s.


wroomwroomoops
11-06-07, 03:03 PM
I recently (ok, a couple of months ago) asked a similar question. It was a 48H front wheel - 26" - for a tandem, and I was wondering if I could do a 5x lacing. Got a few intelligent responses confirming that 5x will be perfectly ok, so I did it. And posted pics of the artifact.

Do you want to see my little artifact?

Batavus
11-06-07, 03:11 PM
I recently (ok, a couple of months ago) asked a similar question. It was a 48H front wheel - 26" - for a tandem, and I was wondering if I could do a 5x lacing. Got a few intelligent responses confirming that 5x will be perfectly ok, so I did it. And posted pics of the artifact.

Do you want to see my little artifact?


Please show me! Oh and I should have mentioned that it is 700c, but I think you all would have guessed that. Thanks!

wroomwroomoops
11-06-07, 03:21 PM
http://i120.photobucket.com/albums/o197/old_fool/bikeparts/DSCN2694.jpg
http://i120.photobucket.com/albums/o197/old_fool/bikeparts/DSCN2687.jpg
http://i120.photobucket.com/albums/o197/old_fool/bikeparts/DSCN2696.jpg

Batavus
11-06-07, 03:41 PM
http://i120.photobucket.com/albums/o197/old_fool/bikeparts/DSCN2694.jpg
http://i120.photobucket.com/albums/o197/old_fool/bikeparts/DSCN2687.jpg
http://i120.photobucket.com/albums/o197/old_fool/bikeparts/DSCN2696.jpg

Wow! That looks amazing! It places the spokes at an even more acute angle to the hub than four cross. Was it very difficult to build?

wroomwroomoops
11-06-07, 03:50 PM
Wow! That looks amazing! It places the spokes at an even more acute angle to the hub than four cross. Was it very difficult to build?

It was one of the simplest wheelbuilds. For me, at least. Everything just fell into place much easier than with the other wheels.

Rev.Chuck
11-06-07, 06:04 PM
Four cross, as a problem, is more dependent on the size of the hub and the rim.What you do not want is for the spokes to cross over the heads of the opposite spokes. This can cause a stress riser and premature failure. If you have a large flange hub it will not be an issue, but with a small flange hub it can be a problem and there is little enough gain to try it, better to keep three cross.

HillRider
11-06-07, 06:07 PM
Four cross, as a problem, is more dependent on the size of the hub and the rim.What you do not want is for the spokes to cross over the heads of the opposite spokes. This can cause a stress riser and premature failure. If you have a large flange hub it will not be an issue, but with a small flange hub it can be a problem and there is little enough gain to try it, better to keep three cross.

I don't think this is an issue with a 40 hole rim and hub. It might be with a 36H.

Sheldon Brown
11-06-07, 06:51 PM
I've just completed the above mentioned build. It's a 40 hole XT tandem hub to Velocity Fusion using Dt Swiss db spokes. It is for a racing-style tandem. I laced it four cross because we didn't have the length for three cross in stock. Now someone has mentioned that would be a bad idea, since the four cross lacing makes the wheel weaker laterally and with the extra forces involved, seeing as this will be a racing tandem, the wheel could buckle. At least sooner than were it a three cross lacing.Cross 4 is the normal pattern for full-sized 40 spoke wheels with normal-sized hubs.

Sheldon "Not A Problem" Brown

Batavus
11-07-07, 04:00 AM
Well, thank you all, especially notable gurus rev.chuck and of course mr. Brown!

This is a large flange hub and the spokes do not rest on the crossing spoke heads at all. So, as I thought before I put the problem before you: this will not be a problem.

Thanks again!

Deanster04
11-07-07, 04:29 AM
Thank you Mr. Brown! Your comments are always settling to controversay.
WOW, 5X Low wind up in those puppies...thanks for the photos.
I raced 36H Large Flange Campy hubs and Fiamme Reds with the spokes tied and soldered for years on both road and track wheels...Had few broken spokes (and that was when the spoke technology of SS spokes was pretty bad). 4X was better than 3X for 36 holes.
I have a cross bike with 4X on 36H Small Flange Campy Hubs (I know it was wrong to do) but have had no broken spokes after 7 years and over 8K miles mostly off road. Have only put the spoke wrench to the wheels twice for a small tweek. Road bikes are all 32H 3X with many, many more miles. I haven't broken a spoke since??? Oh yes, I run the spoke tension on the higher side of the recommended range for the rims I build.