9 x 4 (Cluster) Spoke Length calc

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Dr pepper
Posts: 6
Joined: 29 Jul 2020, 11:41pm

9 x 4 (Cluster) Spoke Length calc

Postby Dr pepper » 29 Jul 2020, 11:45pm

Hello I'm new here.
I've built a few wheels for myself, 32 & 36 spoke.
I just got a couple of rims with 36 spoke holes in a 9x4 pattern.
I've never built a cluster arrangement before, can anyone point me to a spoke calc so I can work out my lengths.
Plus lloking at some pics it looks like they are built in a 2x formation.
An help appreciated.

Brucey
Posts: 39884
Joined: 4 Jan 2012, 6:25pm

Re: 9 x 4 (Cluster) Spoke Length calc

Postby Brucey » 30 Jul 2020, 7:47am

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Dr pepper
Posts: 6
Joined: 29 Jul 2020, 11:41pm

Re: 9 x 4 (Cluster) Spoke Length calc

Postby Dr pepper » 30 Jul 2020, 11:59am

Thanks Brucey, I'm a lot wiser for that.
My rims are per the pic, batavus (rodi), so its an X cluster.
On the front I have a shimano alfine dynohub with disc, and on the back its a shimano deore cassette, the bike is a old banger trek from the 90s.

I dont completely get fractional crossings, obviously you cant have 2.5 physical crossings, is this just a means of compensating when calcing spoke lengths.
I have calced spoke lengths, 248 and 251mm for the dynohub.
The only thing I'm not 100% with now is the lacing pattern, presumably the same as a non cluster wheel, but where do I put the hole gaps.
Might search for a photo so I canwork it out, thanks for your help.

Brucey
Posts: 39884
Joined: 4 Jan 2012, 6:25pm

Re: 9 x 4 (Cluster) Spoke Length calc

Postby Brucey » 30 Jul 2020, 12:36pm

Dr pepper wrote: is this just a means of compensating when calcing spoke lengths.
.


yes

Image

this 'X-pattern' wheel is laced x3 in the normal way , but the clustering makes all the spoke lengths shorter than normal. This pattern is most appropriate if the valve hole is between clusters.

cheers
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Dr pepper
Posts: 6
Joined: 29 Jul 2020, 11:41pm

Re: 9 x 4 (Cluster) Spoke Length calc

Postby Dr pepper » 30 Jul 2020, 2:03pm

Thanks Brucey,
I have enough to hazard a start now.
So its just like a 36 spoke 3x, just ignore the gaps.
Now I have the spoke length and a rough idea on threading up I'll give it a go.
I dont spoe I'll need to be too mindfull of leaving a gap for the valve hole, as there already is one, this I find tricky with round wheels.
I really liked my rigida laser 400's, but I smashed one on a grid.
Do I need special nipples for a non eyelet-ed ally rim, I've only built steel or eyelet-ed rims, might not be 'proper' but one option might be to use 1 spoke length and 12/16mm nipples.

Dr pepper
Posts: 6
Joined: 29 Jul 2020, 11:41pm

Re: 9 x 4 (Cluster) Spoke Length calc

Postby Dr pepper » 6 Aug 2020, 10:35am

Made a start.
Laced up as I would a normal 36 3x wheel, starting on the end of a cluster next to the valve hole, and I laced up the side thats all the same spoke length, thats as far as I got.
Now I've done that I'm going to mark the rim holes with a dry wipe long & short, so's I know which length spoke goes in, and just shove a spoke in the 'ole, and if it falls on the wrong length hole just change it.
Doesnt seem so bad so far.