Spoke Length

carbonfiend

I have broken a rear spoke its Sapim CX Ray. I wanna know what length it is to replace. How do I measure it. I have seen spoke length calculators but none of them have my rims on there, they are Stans No Tubes Olympic and I run DT Swiss 240 hubs

redvee

Take another spoke out and measure from the elbow of the spoke to the tip of the thread, make sure you take one from the same side of the wheel if it is a rear wheel.

Or use your hands to measure one of the otehr spokes and walk into LBS with your hands that far apart asking for a spoke that length, might seem stupid but I've heard of that happening.

rogerwp

With a lightweight wheelset and no doubt lightweight riding how did you manage to break "the world's srongest spoke". I'm assuming it snapped just iding along and not via some whack from a branch wedged in the spokes.

Why not ask the guy who built them, they'll know the exact length and they should supply a replacement free of charge. I know I would if someone ever broke a spoke in one of my wheels.

--
R

carbonfiend

I don't know how it broke as only noticed it when cleaning bike - I did have an off which could have done it as I crashed in to tree/bush and the bike went down on the non drive side where the spoke has broke and I have graze on my hip in fact thats the only reason I can see how it was done.
Gonna take it back to where the wheel was built but I know these spokes are a pain in the ass to get hold off and I can only get the bike seen next week so wanted to see if I could purchase the spoke myself before I took the bike in for repair. Got a race in November so want it all sorted asap.

carbonfiend

The wheel is Stans olympic rim with DT Swiss 240 Hubs

Big Red S

redvee wrote:

Or use your hands to measure one of the otehr spokes and walk into LBS with your hands that far apart asking for a spoke that length, might seem stupid but I've heard of that happening.

It /is/ stupid. It does happen, and chances are the guy doing it leaves with the wrong length spoke.

You can measure them in situ with a ruler or a tape measure, but remember to take into account the bit of spoke that's in the nipple. Spokes are sized in increments of 1mm.

1960ride

Carbonfiend,

It is very easy to figure out spoke lengths using dt spoke calc.
what you need to know is the measurements of the
1. Hub and number of holes
2. Rim The ERTO or ERD is the number you are looking for in this case Stans web site lists it as 536
3. What spoking pattern you are using. Example 2x each spoke crosses 2 others 3x or radial no spokes cross usually on front wheels but on some non drive side wheels with no disks.

You can use a similar spoke type/size when using spoke calc to get the results you need.

I used DT revolution 1.8 x1.5 spokes for the calculation.

Which DT 240 hubs do you have? center lock or 6 bolt
How many spokes are in the rim 32 or 28?
Is the wheel laced in a 3x pattern?

You can order your spokes from the link below for 1.95 euro.

http://www.starbike.com/php/suchen.php? ... =&q=CX-Ray

Here are some spoke calculations for the rear wheel with 28 and 32 spokes 3x using the centerlock hub and the 6 bolt pattern.

Stans olympic rim. using DT 240 32 hole hub with Centerlock disk laced 3x
The rim ERD is 536
260MM non drive side and 258mm drive side

Using the six bolt disk mount the calculations are
258 mm for both sides.

Stans olympic rim. using DT 240 28 hole hub with Centerlock disk laced 3x
The rim ERD is 536
263mm non drive side and 259 drive side
However, if this is your rim set up you will need to use 262 non drive and 258 drive side since the cx ray spokes only come in even lengths.

Once you get the spoke you will need to ensure you have the tool for preventing spoke wind up during spoke replacement. If you are not replacing it yourself ensure the shop that replaces it does it correctly and ask them to let you know the spoke tension on the drive side and non drive side. The spoke tension is the most important part of the build since this is what makes the wheel. Also don't forget to use spoke freeze or spoke prep to ensure the spoke does not loosen after being installed.

Good luck

carbonfiend

Thnx a lot one question though how do i tell if my hub is centre lock or 6 bolt

Big Red S

1960ride wrote:

C
2. Rim The ERTO or ERD is the number you are looking for in this case

Are you sure?
I thought the E(T)RTO pertained to tyre/rim bead, ERD to nipple flats?

If all rims with the same ETRTO number had the same ERD, it wouldn't matter which rim you had. All 26" rims are 559, all 700c ones are 622...

1960ride

Big Red S,

Thanks for catching that mistake, you are correct about the ETRT0 / ERD difference.
E.R.D.

Effective Rim Diameter. This is the rim diameter measured at the nipple seats in the spoke holes, plus the thickness of the two nipple heads. The E.R.D. is needed for calculating the correct spoke length.

E.T.R.T.O.
European Tire and Rim Technical Organization. This is the modern system for designating tire and rim sizes.
Some people also refer to the ETRTO as the Bead seat diamater which will be 559 for 26"mtb rims and 622 for 700c road rims for tire sizing not for the spoke calculations.

Carbonfiend,

Here is a link to the DT Swiss website so you can see which type disk mount you have.
http://www.dtswiss.com/Products/Compone ... 100mm.aspx


Good luck

carbonfiend

I think I'm getting there - am I correct in thinking my ERD for my Stans is 559 ?- I now sussed that my 240's are 6 Bolt not centre lock and my spoke count is 32 and they are x 2 as a single spoke when I follow it only ever crosses two other spokes.

1960ride

carbonfiend,

You are on your way. However the ERD is 536. this is the measurement you need for spoke calculation.
The ETRTO is 559 this is the measurement you need for tire size.

The calculations i gave you above are for 3x spokes. I will recalculate the numbers and give you caclulations for 2x and 3x using the stans rim and the 6 bolt disk pattern.

Did you break a spoke on the drive side?

You need to be sure the spoke pattern is 2x or the spoke will be the wrong size.

Check very closely when counting the crosses.
Look at a spoke starting at the hub the first cross will be almost at the hub flange the second will be about 1 inch from the hub and the third will be about 3 inches from the hub.
You need to be absolutely sure you get the cross pattern correct.

If you are not sure you can post a close up picture of your wheel and i can tell you for sure.

Using a 3x pattern both drive and non drive side spokes would be 258mm

Using a 2x pattern the drive side is 250mm and the non drive side 248mm

carbonfiend

yeah I can see exactly what you mean with the spoke x's yeah it is 3 you're right the first on is right at the hub. I added all the info and get 258 it's non drive side BTW
This how I worked it out
http://www.dtswiss.com/SpokesCalc/Calculator.aspx

robbarker

rogerwp wrote:

With a lightweight wheelset and no doubt lightweight riding how did you manage to break "the world's srongest spoke". I'm assuming it snapped just iding along and not via some whack from a branch wedged in the spokes.

Why not ask the guy who built them, they'll know the exact length and they should supply a replacement free of charge. I know I would if someone ever broke a spoke in one of my wheels.

--
R

You big tease Roger! :-)

I do like the latest edition by the way - very nice layout to match the first rate content.

rogerwp

carbonfiend wrote:

...

Gonna take it back to where the wheel was built but I know these spokes are a pain in the ass to get hold off and I can only get the bike seen next week so wanted to see if I could purchase the spoke myself before I took the bike in for repair. Got a race in November so want it all sorted asap.

Did the guy who built it supply the spokes? If so he'll probably have spares, in which case you don't need to take him a spoke. Phone him up. A lot easier than trying to purchase one spoke.

I would suggest 260.

--
R

rogerwp

You big tease Roger! :-)

I do like the latest edition by the way - very nice layout to match the first rate content.

Cheers Rob.

Remember, never trust ERD measurements given by the rim manufacturers.

--
Roger

carbonfiend

yeah he did but he's moved on now - ordered some from starbike so see how it goes

Terrytibbs

Holly cow you snapped a cx-ray :O.

I folded my rim so much that my hub flange hit the floor and no spokes snapped .

I take you've sorted the size now then?

carbonfiend

yeah I think so I followed the instructions given here and came up with 258m ordered them and they are on there way so time will tell. I've broken a number of items (including bones} racing and riding MTBs I now take everything about strength that manufactuors say with a large dose of salt.

carbonfiend

yeah I think so I followed the instructions given here and came up with 258m ordered them and they are on there way so time will tell. I've broken a number of items (including bones} racing and riding MTBs I now take everything about strength that manufactuors say with a large dose of salt.

carbonfiend

yeah I think so I followed the instructions given here and came up with 258m ordered them and they are on there way so time will tell. I've broken a number of items (including bones} racing and riding MTBs I now take everything about strength that manufactuors say with a large dose of salt.

carbonfiend

yeah I think so I followed the instructions given here and came up with 258m ordered them and they are on there way so time will tell. I've broken a number of items (including bones} racing and riding MTBs I now take everything about strength that manufactuors say with a large dose of salt.