Author Topic: Comparison between 3 leading-3 trailing and 3 cross wheel build  (Read 1093 times)

OK, so this is a bit of an oddball thing to compare, but I built my commuting bike up with a 3 leading 3 trailing spoke pattern (as usual Sheldon has the answer if you don't know what I'm talking about http://sheldonbrown.com/org/iro/584/pages/06.htm).

This is a bit of an oddball build, but very pretty to look at. There are various variants on it. Sheldon shows no spokes crossed, I've seen all the spokes crossed. I read that with all the spokes crossed it's difficult to true. I tried to build it with no spokes crossed, but found it impossible to keep true after I de-stressed it during the build process, so compromised by crossing one set of spokes in each group like this:


This wheel held up for two years of daily commuting through all weathers, until I finally wore the rim out.

I never really worried too much about it, but I did notice that the bike handled very differently when the tyre pressure was a bit soft compared to pumped up hard.

When I rebuilt the wheel I used the same hub, rim and spokes (cheapskate!) and found that there were rub marks where the spokes crossed from the 3 leading 3 trailing pattern. So I guess the wheel had a bit of lateral flex after all.

As a conventional 3 cross wheel the ride is really noticeably harsher. The 3 cross build is definitely stiffer.

So, my guess is that 3 leading 3 trailing builds are better suited to a rear wheel than a front wheel and that this pattern might take some of the sting out of a build on deep section rims.


gordon taylor

Re: Comparison between 3 leading-3 trailing and 3 cross wheel build
« Reply #1 on: May 07, 2008, 03:48:17 AM »
I agree, up to a point.

I used that pattern on my commuter last summer, but found it really difficult to get the wheels round. I could get them true, but not round.



My spokes had several tight crossings, as you can see. I gave up when a spoke broke on the rear wheel - you virtually have to dismantle half the wheel to get a spoke replaced.

The wheels do look lovely, and it is certainly worth trying as an interesting wheelbuild, but I'm back on normal patterns for a while.

Re: Comparison between 3 leading-3 trailing and 3 cross wheel build
« Reply #2 on: May 07, 2008, 09:08:33 AM »
It used to be that you'd go to 4X for a touring wheel, where a little more compliance was required. I'm not sure it actually made a noticeable difference.

What I would say is that if there's been obvious spoke movement on your 3/3 wheel it means the spokes are under more stress and more likely to fatigue.

On the other hand, building your own means you can have fun with different ideas.

Re: Comparison between 3 leading-3 trailing and 3 cross wheel build
« Reply #3 on: May 07, 2008, 09:50:52 AM »



My spokes had several tight crossings, as you can see. I gave up when a spoke broke on the rear wheel - you virtually have to dismantle half the wheel to get a spoke replaced.

I did a bit of reading before building mine. Two things worked for me, first off I used small flange hubs, so you don't get such tight spoke corssings, secondly I'd read that crossing all the spokes, as you tried, was unnecessary and makes them difficult to true, hence my partially corssed solution.

I think that the way I built mine would have worked really well on a large flange hub. It would certainly have looked better.

Another odd thing, which I haven't yet had a chance to compare is cross wind performance.
I found that as a front wheel it got really blown around and I think that's because it's basically got big "holes" in it!

rogerzilla

  • l33t h4X0r
Re: Comparison between 3 leading-3 trailing and 3 cross wheel build
« Reply #4 on: May 12, 2008, 09:23:20 AM »
x4 was apparently proven to cause fewer spoke breakages in racing, but it's not advisable for spoke counts of less than 40 because the rim entry angle gets silly and introduces the risk of breakage at the rim end. 

Your old-school racers used to use 28 spokes front, 40 spokes rear, which is pretty much ideal to handle the weight distribution.  In fact, I wonder whether they were any heavier (with sprint rims) than the boutique wheels on new bikes?
Never tell me the odds.

border-rider

Re: Comparison between 3 leading-3 trailing and 3 cross wheel build
« Reply #5 on: May 12, 2008, 11:18:41 AM »
In fact, I wonder whether they were any heavier (with sprint rims) than the boutique wheels on new bikes?

Likely not, and even more likely the weight distribution was/is better so that there is less rotating mass toward the periphery.