wheel-building expert advice sought

[Cyckelgalen]

If I may jump in with another wheel building question, I want to build a 20" rim with 74 mm OLD hub and 20 spokes. I am correct in assuming that smaller diameter wheels are sturdier and require fewer spokes and spoke crossings?
How many crossings would you recommend for a front wheel ?

[Brucey]

If I may jump in with another wheel building question, I want to build a 20" rim with 74 mm OLD hub and 20 spokes. I am correct in assuming that smaller diameter wheels are sturdier and require fewer spokes and spoke crossings?
How many crossings would you recommend for a front wheel ?

'yes' and 'depends on the hub really' respectively

[drossall]

Two-cross seems quite common. There are some Dahon wheels here with a picture that blows up well so you can see detail. But I've got at least one pair with a front built radial, and they are fine too, even though I'm not the lightest of riders. Here's the bike concerned. Obviously your hub will dictate the number of spokes anyway, but 36 on a 20" wheel would make it almost into a disc, they'd be so close together

[531colin]

If I may jump in with another wheel building question, I want to build a 20" rim with 74 mm OLD hub and 20 spokes. I am correct in assuming that smaller diameter wheels are sturdier and require fewer spokes and spoke crossings?
How many crossings would you recommend for a front wheel ?

Is there any torque load from hub brake or drive?
Is there any side load eg. Cornering a trike?

[Cyckelgalen]

Hi 531Colin, no, there is no torque or unusual lateral loads. It is for a Dahon folder that came originally with radial lacing, probably adequate for a front rim-brake wheel, but I assume that a crossing pattern will be an improvement.
The hub has narrow flanges (47 mm diameter) but they are only 44 mm apart. It is Dahon rebranded hub, 74 mm OLD instead of the standard 100 mm for front wheels.
We are talking 20 spokes, so should I go for a X2 cross lacing?

[Cyckelgalen]

Actually, the hub may well be the same pictured in dossall's link. X2 lacing if I'm not mistaken.

[Brucey]

if rebuilding a wheel/hub that had already been built radial I'd probably go with radial spoking again

[Cyckelgalen]

Hi Brucey, well, the rim was built radially, the hub is brand new. I just wanted to discard the original mediocre Sanyo hub dynamo that I hardly use and is extremely draggy, awkward and inefficient.

[531colin]

Radial spoking is fine with no torque load, and it means spokes will hit the rim at 90 degrees, and you can put all the spokes outside the spoke flange giving a (bit) better bracing angle… but any improvement is welcome with a narrow hub.
Spoke crossing is necessary if you are transferring torque between hub and rim. For a small flange hub you used to aim for spokes to be fully tangential to the hub, 4cross 40 spoke for example; big hubs like hub gears can use less than fully tangential.