Spoke length calculations

Maltese Falcon

Maltese Falcon

Likes Dirt
Hi

I have some tune hubs, 32 spoke King & Kong & Stans Rims, Flow EX & Crest 650B

I have contacted stans but they don't have Tune Hubs on their list for spoke length, can anyone advise me on what to purchase re spoke length

thanks
 
S

SummitFever

Eats Squid
Have you got the rims? If so, measure the ERD yourself using the nipples you intend to use for the build. This is the method I use and will get you a guaranteed spoke length that results in proper engagement with the head on the nipple. When I measure stan's 26" rims with this method I get an ERD 4mm more than the claimed ERD off the stans website (544mm versus 540mm). Quite a few other wheelbuilders have come across this as well. For this reason, I'd suggest measuring the ERD yourself.

Should be a nice wheelset. The Tune King/Kong hubs are excellent. Nothing comes close to them for strength v's weight.
 
S

SummitFever

Eats Squid
If you post up the ERD, I'll plug it into my spocalc spreadsheet that I used for my last King/Kong build and give you a second opinion on your calculated spoke lengths. Also, what spokes will you be using?
 
link1896

link1896

Mr Greenfield
SummitFever said:
Have you got the rims? If so, measure the ERD yourself using the nipples you intend to use for the build. This is the method I use and will get you a guaranteed spoke length that results in proper engagement with the head on the nipple. When I measure stan's 26" rims with this method I get an ERD 4mm more than the claimed ERD off the stans website (544mm versus 540mm). Quite a few other wheelbuilders have come across this as well. For this reason, I'd suggest measuring the ERD yourself.

Should be a nice wheelset. The Tune King/Kong hubs are excellent. Nothing comes close to them for strength v's weight.
Click to expand...

How the hell does one balls up ERD by 4mm?
 
Maltese Falcon

Maltese Falcon

Likes Dirt
SummitFever said:
If you post up the ERD, I'll plug it into my spocalc spreadsheet that I used for my last King/Kong build and give you a second opinion on your calculated spoke lengths. Also, what spokes will you be using?
Click to expand...
thanks!
Stans Flow ex on the front
Size 650B x 29.1mm
Hole # 32
Brakes Disc
Weight 510g
ISO 584 x 25.1
ERD 562
Tape Width 25mm

Stans Crest on the rear
Size 650b x 24.4mm
Color Black
Hole # 32
Brakes Disc
Weight 365g
ISO 584 x 21
ERD 565
Tape Width 25mm


I will be using DT Swiss Competition DB Silver Spokes
 
S

SummitFever

Eats Squid
link1896 said:
How the hell does one balls up ERD by 4mm?
Click to expand...
Stan's don't factor in the spoke head engagement which for your average nipple adds another 2mm per end to the spoke calcs (or ERD) to get the threads finishing right at the bottom of the nipple slot.

Maltese Falcon - are you building them 3x

If so, based on your ERD's I get

Front: left - 271.8mm; right 272.8mm (use 272mm spokes both sides)
Rear: left - 274.3mm; right 272.6mm (use 16 x 274mm and 16 x 272mm).

Did you actually measure the ERDs or are those the Stan's claimed ERDs?
 
Maltese Falcon

Maltese Falcon

Likes Dirt
Yes they are 3x

& yes the ERD is from the stans website. I have in the past only used Hope hubs but wanted something different this time, hence the tune hubs.

Again, thank you for all you help

Rizzo
 
hazza6542

hazza6542

Eats Squid
Sorry to hijack but a bit confused here as well. Building Stans Flow EX's to Pro II's, don't understand what length spoke to buy when it says left and right side are slightly different, and the 2mm difference with the nipples.

565.jpg

Would this be correct?
 
The Duckmeister

The Duckmeister

Has a juicy midrange
Nipple length shouldn't affect spoke length if they're calculated properly so they thread on fully. Whatever length nipples you use, the spokes should always screw into the head - finishing flush with the head slot is a good depth guide.

My method for measuring ERD is similar but not exactly the same as that linked by SummitFever. Take two long spokes, insert into opposing spoke holes in the rim, and screw a nipple onto each one so the tip of the spoke sits flush with either the slot or the head of the nipple; doesn't matter which, just as long as you're consistent. Pull the spokes together & mark a fine line across where the spokes overlap. Remove from the rim, lay flat with the marks aligned & measure between the underside of the heads of each nipple, so you're measuring the bearing points of the rim.

The DT Swiss spoke calculator that I use takes ERD this way and calculates the spoke length from it and makes allowance for the nipple heads.
 
Maltese Falcon

Maltese Falcon

Likes Dirt
SummitFever said:
Stan's don't factor in the spoke head engagement which for your average nipple adds another 2mm per end to the spoke calcs (or ERD) to get the threads finishing right at the bottom of the nipple slot.

Maltese Falcon - are you building them 3x

If so, based on your ERD's I get

Front: left - 271.8mm; right 272.8mm (use 272mm spokes both sides)
Rear: left - 274.3mm; right 272.6mm (use 16 x 274mm and 16 x 272mm).

Did you actually measure the ERDs or are those the Stan's claimed ERDs?
Click to expand...
I ended up building the wheels based on your length calculation SummitFever & they are fine, but I am now going to re build the rear with a Flow rim as well. Since the ERD from the Crest to the Flow is 3mm difference, does this then mean that I need to have 3mm longer spokes for the rear?
 
S

SummitFever

Eats Squid
In theory you'll need spokes half of 3mm longer (eg 1.5mm). If you had good engagement of the spoke into the nipple (ie. when tensioned, spoke end was at or near the top of the nipple) and you're using brass nipples on the new build you can probably get away with reusing your current spokes.
 
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