Wheelbuilding questions tips and ponderations

[JoeH]

The hub does not have conventional spoke holes. If you search Sachs HR 90V, you'll see what I mean. The inner spoke is the one you see the spoke head.

Stick a couple of pics up

 

[EightBallFlyer]

I have a problem. I have been attempting to build a rear wheel for a one off bike with 4 saddles. It has a 36 hole Sachs HR-V coaster hub. They were used on swedish military bikes, in the 50's and 60's. The rim is for a 23" moped/light motorcycle. I've used the 3× pattern and tried crossing the spokes to reduce spoke length. I have an opening in between the spokes for the valve. After my latest attempt it seems that the outer spokes are too long and the inner ones too short, but i'm not 100% sure that's the case for all of them. What am I doing wrong/mässing?

Wow! That's an amazing looking bike. I've never seen anything bigger than a tandem in the UK, and occasionally a tricycle.
Sorry I can't help.
Good luck.

 

[Dicky71]

Wow! That's an amazing looking bike. I've never seen anything bigger than a tandem in the UK, and occasionally a tricycle.
Sorry I can't help.
Good luck.

It's one off, built for members of a student union in Gothenburgs technical college, in the late 50's. It was built by Monark cycles and yes It's pretty impressive but a bit of a PIA to work on. It has kept my son occupied while he was studying. He's had more fun with the student union than the actual studying. SURPRISE SURPRISE

 

[bikeworkshop]

The hub does not have conventional spoke holes. If you search Sachs HR 90V, you'll see what I mean. The inner spoke is the one you see the spoke head.

I've built a few similar wheels.

Those slotted spoke "holes" have some benefit - in some instances a spoke head doesn't have to be pushed through from the opposite side.
Other hubs lika s-a dynamo have them - it's a pita to lace because the spokes can just fall out

Leading and trailing spokes will be the same length.

If the hub flanges are equidistant from the centre, then both left and right flange (nds/ds) spokes will be the same length.

Consequently if some of your spokes appear short, then something isn't in the right place.
It could be a spoke head not at the end of the slot, or one spoke in the wrong hole, or a nipple hung up in the rim, or the hub is laced wrong, the hub spoke holes are out of phase with the rim.
(This is possibly it - it seems totally confusing until you realise. The wheel almost looks correct.)

Post a picture and it should be clear.

 

[JoeH]

My thoughts, prompted by bike workshop is if the out head spokes are too long and inner head too short, that means they are going in the wrong holes, but the length is close enough.
Therefore:

Leave the lacing as is, BUT move the outer/longer to a further rim hole, and move the inner/shorter to a closer rim hole.