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Discussion Starter · #1 ·
Hey guys... I'm going to attempt to build my own wheelset after many brand wheels have failed me. I've been reading threads for the last few weeks and still need some help with spoke length calcuations. I'm waiting for the Mavic EN 821 29er rims (chosen over Stan's ZTR Flow Ex 29) which will be here next week.

I understand that the Mavic rims have eyelets and is asymmetrical. I need help calculating the ERD to get the right spokes. I know I'll have to go with 16mm brass nipples. I'm going to use DT Swiss Comp 14/15 spokes.

I will greatly appreciate any help you guys can give me. :)

Rear:
142x12mm Chris King Hub

Front:
15mm Thru-Axle Chris King Large Diameter Hub

Rims:
Mavic EN 821 29” Rims

ISO 142x12mm Rear Specs:
Axel Width (mm) 142
Flange Diameter Drive Side & non-Drive Side (mm) 57.4
Center to Flange Drive Side (mm) 20.1
Center to Flange non-Drive Side (mm) 33.9

ISO 15mm LD Front Specs:
Axel Width (mm) 100
Flange Diameter Drive Side & non-Drive Side (mm) 57.4
Center to Flange Drive Side (mm) 31.6
Center to Flange non-Drive Side (mm) 23.3
 

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mtbpete
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Here's an excellent spoke length calculator:
Spocalc, by Damon Rinard. A free Excel spoke length calculator.

There's a box for the offset distance. You can either enter the hub and rim dimensions directly or enter/choose them from the worksheets provided.

Brass is always a stronger than alloy nipples, but alloy nipples are fine as long as you're spokes are long enough that they thread into the head of the nipples. Definitely use brass if you err on the side of spokes being a little short or are riding in a corrosive environment, such as salty winter streets in the northeast or near the ocean.
 

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Discussion Starter · #4 ·
Ah man... I great appreciate it!!! How did you measure the erd? How's the build going?

Sent from my SCH-I545 using Tapatalk
 

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Just building up a rear wheel consisting of a Mavic 821 and Hope hub. Had some confusion on rim orientation because the sticker on my rim is incorrect, thought I'd save you some trouble:

http://www.tech-mavic.com/tech-mavic...hemes/2_21.pdf

Page 31:
View attachment 883274
Good to hear other have the same mixup with the sticker. Mine's backwards as well.

Incidentally, I'm building 26" 821s with CK hubs (142x12 rear, 15mm LD front). I have a bunch of 256mm Alpine 3s kicking around, I'm about to order some 258s since I'm measuring the following:

Front
Left spoke length: 256.9mm
Right spoke length: 257.9mm

Rear
Left spoke length: 258.1mm
Right spoke length: 256.6mm

Lengths calculated for DT 16mm nipples and without adjusting for offset

Anyhoo, will see how they build up. Super nice rims
 

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Discussion Starter · #6 ·
Did you account for the spoke hole offset when calculating the erd? I'd like to know the procedure you used to calculate the erd if you don't mind sharing.

Good to hear other have the same mixup with the sticker. Mine's backwards as well.

Incidentally, I'm building 26" 821s with CK hubs (142x12 rear, 15mm LD front). I have a bunch of 256mm Alpine 3s kicking around, I'm about to order some 258s since I'm measuring the following:

Front
Left spoke length: 256.9mm
Right spoke length: 257.9mm

Rear
Left spoke length: 258.1mm
Right spoke length: 256.6mm

Lengths calculated for DT 16mm nipples

Anyhoo, will see how they build up. Super nice rims
 

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Did you account for the spoke hole offset when calculating the erd? I'd like to know the procedure you used to calculate the erd if you don't mind sharing.
I was just editing my post to say I did not account for offset :)
 

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.... I know I'll have to go with 16mm brass nipples. I'm going to use DT Swiss Comp 14/15 spokes....
.
just starting to research a similar build, the nipples are Mavic proprietary:

Fore | Mavic

which may affect spoke choce as well. I was trying to find info on that when I found this thread.

Edit: rim package includes adaptors to use std nipples on non-mavic hub/spoke combo's.
 

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With today's announcement that CK are going to be making an XD driver, I've changed up my rear wheel build from a Hope Pro 2 Evo to an existing CK ISO 135.

I've ran the numbers in three different spoke calculators and get the following averages:

R 256mm
L 257mm


These don't take into account 16mm nipples, which from the DT Spoke Calc, 3mm needs to be deducted bringing the spoke lengths to:

R 253mm
L 254mm


Seems to be slightly different numbers from what everyone else is getting.

Wondering if anyone out there has already build up a wheel with this combo?
 

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Discussion Starter · #13 ·
Just received my rims today and wanted to share a photo with you guys. Haven't measure the erd yet. Will do that over the weekend and report back.

 

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So after some thought I decided to try building with the leftover 256mm and 254mm Alpine 3s I had kicking around from a previous build. The length ended up being very good.

In summary:

I built a rear CK ISO 142mm onto a 26" 821 using DT 16mm nipples

Left: 256mm
Right 254mm

I could have used 256mm both sides, but 254mm worked very well, not too short at all.

Later this week I'll build the front. I'll be using 256mm both sides.
 

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Discussion Starter · #15 ·
I got some dt comp spokes and tried lacing earlier but stopped because the spokes had a very tight fit on my CK hubs...and when you put the spokes in, it marrs the spoke holes. Is that normal?

Sent from my SCH-I545 using Tapatalk
 

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Trying to build my first wheels with a set of Mavic En821 and Saint Hubs, as it is my first build need some advise here...Went on two spoke calculators and got the following spoke lengths
Not sure on which size should I go with 16mm nipples and CX-Ray from Sapin...
Capture1.JPG
Capture2.JPG
Edd_Spoke_Front.jpg
Edd_Spoke_rear.jpg


Cheers
 
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