tyrion

Front wheel (for commuting 220# Clyde, easy trails, maybe touring):

* VELOCITY DYAD 700c 36 spokes
* Shutter Precision PV8 dynamo hub
* SAPIM RACE J BEND SILVER DOUBLE BUTTED 14 X 15 X 14G OR 2.0 X 1.8 X 2.0MM SPOKES
* 4 cross lacing pattern

I arrived at this build by the prowheelbuilder.com building guide tool that walks you through component selection (pick a rim, pick a hub, pick spokes, pick lacing pattern). The tool seems well thought out and seems to limit component selections to things that work together.

The recommended Sapim spokes were the Race (2.0 - 1.8 - 2.0), the Leader (straight 2.0), and the Strong (2.3 - 2.0). (The Sapim Force (2.18 - 1.8 - 2.0) seems like it might be the best choice here but prowheelbuilder.com doesn't offer it.)

So my main questions are

1) Sapim Race spokes or Sapim Strong spokes? (I'm assuming the Race spokes would provide a slight flex/comfort over the Strong spokes, for which I'd sacrifice maximum strength)

2) 4-cross lacing was recommended over 3-cross - does this make sense?

fietsbob

well, a 36 hole 4 cross , the chance the spoke will pull out thru the hub flange is pretty much Zero..


I doubt you will feel any difference riding , 1 spoke vs the other.. DT alpine has offered the 13-15-14 spoke for a long time..
I have been fine with straight 14 / 2.0.... but you all sweat 'Best' over adequate..

seeking comfort.. there your tire choice is that factor .. fatter=lower pressure.





.....

tyrion

Yeah from internet reading my impression was that there were these issues with 4 cross, but the wheel building guide recommended 4 cross. 3 cross was "approved" but not "recommended". 2 cross and 1 cross and radial were "not approved".

Bill Kapaun

For a front wheel, 32 spokes should be plenty.
That hub has rather large (2.7mm) spoke holes. For that reason, I would use the Strong to help better "fill the hole".
3X is more than strong enough and would save about the weight of 1 spoke.

My next front wheel will be a 32 X2 and I have 20 lbs. on you.

tyrion

Good tip, thanks.

fietsbob

4 x the spoke path, at a tangent ..1st cross is the opposing spoke, to the opposite side of the rim..

I have 3 Schmidt.. 2, 32 hole 3 cross 26, 1, 20".. 1, 28 spoke radial but its a Hub designed to be no other way, brompton rim..

& 1 shimano brompton wheel .. they used 1 cross. the 2 28 spoke wheels are 16"..




have several other bikes , i built the wheels .... you are jobbing it out.

FBinNY 

There's very little material difference between 4x and 3x on a 36h wheel.

However, whatever benefits or drawbacks one might factor, argue for 3x over 4x on a front wheel.

The logic is simple and straight forward. 4x offers more torsional rigidity, but that's moot for a front wheel. Of course it might matter a bit for a disc brake wheel, but, even there we're back to how much we're talking about.

On the flip side, the longer spokes and shallower bracing angle of 4x work to reduce lateral rigidity, which is highly desirable in front wheels.

The difference though small argues for 3x, but keep in mind that it's probably not material enough to fret over in the real world.

BTW and FWIW, the historic rational for 4x 36h wasn't mechanical, it was economic. Full tangent (4x/36h, 3x/28h) minimizes the effect of flange size on spoke length. In practice the difference for front and rear hubs with typical differences in flange diameter is near zero. This saves time and money by allowing manufacturers to use the same spokes in front and rear wheels. This may be a consideration for a bicycle tourist, because it means that he has emergency spokes in the other wheel in case a situation arises.

Bill Kapaun

I'm ignorant about dynamo hubs, but is 2.4W enough?
My question is basically- do you have to "overdrive" your headlight in order to produce enough power to have a headlight?

ThermionicScott 

Dyno-driven headlights are usually 2.4W, and hubs are usually 3.0W, so that they can also power a 0.6W taillight. 2.4W hubs are becoming more popular for those of us who don't mind sticking to a battery taillight.

P.S. These hubs do produce a full 3.0W when used on small-wheeled bikes, their original purpose.

tyrion

I'm just learning this stuff but I think the new LED lights need less power than the older incandescent lights. And the PV8 dynamo is "StVZO approved" FWIW.