24" KH Schlumpf spoke length and pattern

Unicycles and Equipment
1

I’m trying to determine which spokes to order for a KH 24 rim and a Schlumpf.

First, I assumed a 3 cross pattern, because I thought that was normally used.
It’s implied in the Schlumpf manual: “Some approximate lengths (for triple crossing)”
Though on the UDC spoke page it says “We recommend 4 cross pattern for 20 and 24 inch wheels, 3 cross for 26 and 28 inch wheels”

Triple cross IS the way to go for a 24" Schlumpf muni wheel… right?
And don’t KH24 unicycles come with a triple cross wheel?

Triple cross is also implied by all the suggested spoke sizes, being close to 230mm. (online calculator shows 4 cross being more like 245mm)

Varying sources show different lengths, but these forums and KH’s site suggest 227mm. So I’d go with that unless someone can change my mind.

227mm

http://www.krisholm.com/khu/kh-schlumpf
227mm

http://www.krisholm.com/khu/rims
227 mm

http://www.schlumpf.ch/uni_engl_einbau.htm
226 mm

http://www.krisholm.com/khu/rims ERD of 24" KH rim = 496 mm
http://www.schlumpf.ch/uni_engl_einbau.htm: “92mm for flange diameter and 67mm for flange”
The Schlumpf site links to this “spokulator” and using the above values I get 229.7 mm.
This is a bit strange because it conflicts with the 226mm suggestion which is on the Schlumpf site, from where the “spokulator” link is found!

“triple cross” = “about 230mm”

Also, is there any reason I should/not go with “USA brand” spokes at UDC?
I’m going to have my LBS put it all together, but I want to be able to get them the right parts.

2

Since the hub has such large flanges I would go with either 3x or even 2x so the angle of the spoke going to the rim is not so severe. I would not bother getting spokes from UDC and just let the bike shop use their own spokes. They will choose the right length and it will probably be cheeper.

3

3-cross 227mm worked perfectly for me.
Your LBS may be cheaper for the spokes but tell them the correct length to use - they won’t have a clue about the Schlumpf hub dimensions (and probably the KHU 24" rim too) as it won’t be on their bike wheel calculators.
The best calculator for unicycle wheel sizes on the internet is on Unicycle.com UK.

4

Using that calculator, I choose KHU/Schlumpf hub and 24" Kris Holm Freeride 24 - 09.

I get 229mm.

I told my LBS I need 227. He said he can get 226mm and the 1mm difference is no problem. But if 229 is the real measurement, now we’re talking 3mm shorter.

I don’t know how much wiggle room I have to work with… and in which direction.

Should I get the 226’s from my LBS or fine 227’s online?

5

there is a way to calculate spoke length for any hub on a spoke calculator. You need to know some dimensions though. I know you need to know the exact rim size, exact distance between spoke hole, distance between flanges and another thing or 2. I just took a course at a local bike shop on wheel building. This probably doesn’t help much but you could easily figure it out if you had schlumpf dimensions using a googled site

6

it’s up to you, the LBS should have in stock a variety of nipple lengths to make up the difference. A mm here or there won’t cause too much a problem.

if the spokes are too long you won’t get the tension, too short and you won’t get the strength.

7

The calculator you suggested uses a different ERD for the pre-2009 rim (494mm) versus 2009 (496mm).

This makes the pre-2009 spoke length 228mm, and the 2009 length 229mm.

Which rim did you use?
If you were to use a 2010 rim, and had a choice between 226mm or 228mm spokes, which size would you pick? Why?

8

I used the pre-2009 rim and I would pick 228mm spokes.

However there was a significant price difference I would go for 226mm with longer nipples: standard is 12mm but 14 and 16mm are also available.

It really doesn’t matter that much, I’ve spent hours pondering the same dilemma and gone with what I thought wouldn’t work well as they were too short. Once built it’s easier (and cheaper) to switch in longer nipples than replace spokes that are too long.

Relax and take the plunge, it’s very satisfying!