says it has a 596mm erd, while the dominator2 rim is 595mm.
I see that the .doc chart gives length of 284mm spokes for dominator2 rim with nimbus isis36h hub.
The udc calculator gave me 285.36mm spoke length for velocity dyad 596mm erd.
Would I be able to use the nipples and spokes from my current wheel…? or do I need to buy new nipples and new spokes(longer spokes? round up to 286mm?)
It would be nice to not have to spend on parts that I dont need (but maybe buying a new hub and parts to make an entire different wheelset will allow mo to switch from light,pavement-purpose 29er to a muni-oriented wheelset)
Sorry…this will be my first attempt at building wheel and I’m not too sure where I’m going thus my noob questions
Luckily for you your looking at a listed unicycle rim. Mine were both mtb rims because I want to roll tubeless
Go with udcs suggested length 1 or 2mm out should be ok. Worst case for peace of mind you can take your 12mm nipples back out one by one and get some 15mm ones to take up more spoke thread. Heaps cheaper than useless length spokes…
For non uni specific rims someone posted a great unicycle website with their own calculator, dropped in all the rim and hub details and I went for it. Only had to round up half mm length. Perfect!
Just can’t remember the website… I will find it soon. But sounds like you dont need to input different rim details
I wanted to create a thread like this but since it already exists I will just add my two cents.
I’m about to build a G29 and I am hesitating between using a kh freeride rim and a nimbus dominator 2, but I’m a bit confused.
The hub is a kh schlumpf hub (M0658, not the 2016 one).
For the Kh Freeride 29" rim:
-On the .doc it says 283.
-On this kris Kris Holm pages for the same hub it says “Spoke Lengths: 227 mm (24” rim), 251 mm (26”), 282 mm (29" rim), 360 mm (36" rim)"
-If I choose the same rim on the calculator it says “The length of spokes you need based on the input values below is 279.74mm”
For the Dominator² 29 rim:
On the .doc it says 278
The calculator gives 276.7
So, What spoke length am I supposed to afford
If I choose the 29" kh 47mm freeride rim : 283, 282, 279.74 (279 or 280?) ??
If I choose the 29" D² 42mm rim :278, 277, 276??
It’s more precise than any other calculator.
(except for DT, but they don’t allow nipples of the competitor, and are somewhat seclusive about the result).
Rogers formula cannot be more than 2 mm wrong, but with spokes-size increments of multiple mm you could take wrong decisions on info that could have been more accurate.
Are all of these lengths for the same lacing pattern?
Get the hub and whichever rim you choose. Measure them, use the spoke length calculator of your choice, then order the spokes. It takes a little longer before you can lace the wheel, but then it all works.
If you don’t trust yourself to measure the parts correctly, I would send KH an email and ask for them to verify the hub dimensions, and the ERD/offset of the rim. Then still use a good spoke length calculator. For the D2 contact UDC to get the info, and while you’re at it find out what tension is recommended.
I have seen too many rims and hubs that varied from the published spec to trust without verification. Rims seem to be more of a problem, but In the last two years I had one hub that was quite a bit different than the published dimensions.
Thanks
The funny thing is: now I have to deal with a 4th different spokes length for the kh rim (280) and a 3th for the D² rim (277).
The question is which one among 283, 282, 280 and 279 (279.74) am I supposed to use if I choose the kh rim, and which one among 278, 277, 276 (276,7)for the D² rim?
Your calculator gives numbers that are close to what Roger’s calculator gives, so does that mean that both the .doc and the kh website are wrong?
Kh 29 freeride rim and D² rim are some classics used by many unicyclists, and kh Schlumpf hubs are often used on those rims I guess, how is it possible that for such a classic couple of combinations we see contradictory numbers for spoke length?
I have the same issue with knowing what is the max spoke tension that my schlumpf hub is supposed to support.
I know that I have to avoid to overtight the spokes on the schlumpf but if I buy a tool to read the spoke tension, what exactly is “to much”?
For tightening my spokes on my G26 I asked terry to record the sound of his spokes on his G26 and based my overal tension on this tune before truing my wheel.
For the G29 I’d also like to have a number to know exactly what is the tension I have to avoid, or am I supposed to create a thread asking G29 users to record the sound of their spokes when they pinch it? (I could :D)
But that is another subject.
That would not at all surprise me. And that’s exactly why I spend a full Saturday to make it (and verify it to the extreme): to avoid unnecessarily surprises.
As long you feed it correct input, it will return the correct output.
So different output can be caused by [a] different input and by [b] rounding differences (some ceil, some floor, some expect you use certain nipples, some think ahead of unavailable length-increments).
My calculator eliminates problems B (and is using a mathematical more accurate approach).
To eliminate problem A you have to check if all your input is correct (including the lace pattern, as jtrop mentions).
And with certain lengths I’d also expect a bit of stretching of spokes under tention (depending on diameter and material and tention).
If I would be in your shoes, then looking at your numbers I’d would trust the calculators better than the sheets.
The calculation for our calculator works to 4DP - but there are 2 problems here.
The ERD on Kris’s rims are incorrect due to offset problems and some historic problems with the rim dimensions. Both our calculator and Leos will suffer the same problems here and it can make quite a big difference. The calculator that we use to double check with is Justin’s as it does offsets, it really does go the whole distance!
We are working on an updated version of our spoke calculator, but it is just not quite ready for release. It will be a few weeks away (we have some other stuff as well for you!)
We are also going to share data with Justin so in a future version of his calculator he will have a unicycle dropdown for rims and hubs to help with people who are using offset rims and disc hubs.
Apologies for suggesting yet another option, but I always use http://www.sheldonbrown.com/rinard/spocalc.htm - it’s 100% accurate given the correct input and allows input of dish and offset (and various other odd things you probably don’t need). The database won’t be any use for unicycles, but as with other options you just enter the data for your rim and hub.
Another good interface for spocalc is www.lenni.info.edd. I find that the results are identical to Justin’s calculator. I built an Ebike wheel a month ago that I used both calculators for.
Just remember that the nipples you use, and how you prep a rim can have an impact on the ERD, so databases may give different results than you need. What I mean by rim prep is that if I build with a non eyeletted rim I bevel the edges of the nipple seat to better match the shoulder of the nipple. This can lower the ERD by 1-2mm’s.
So if someone wants to order from your web shop a 29" kh freeride rim and the spokes that are needed to fit a kh schlumpf hub (which is likely to be me if I choose this rim since it’s out of stock in France) which spokes and nipples will you send ? (lets say black spokes)
Same question if the rim is a 29" D² (an all black version of the blue one :without the chromed braking surface, if it has any importance).
Edit: I ask it in this thread rather than on a PM conversation because I think this is one of the purposes of this thread : gathering legit data (and calculators as well).
After discussions with unicycle buddies I ordered the 47mm kh freeride 29" rim and 282mm black spokes.
This should go just fine as I have been told than Romain From cdk put 282mm spokes on kh rim + Schlumpf hub, wether it’s a 38mm or a 47mm rim and it fits without any issue.
I don’t know which generation of Schlumpf hub you’re using but generation 4 hubs have a different flange geometry than generation 1 to 3 that results in different spoke lengths.
