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Going from 3-cross to 2-cross, how does it effect length?(17 posts)

Going from 3-cross to 2-cross, how does it effect length?niteschaos
Feb 5, 2003 7:35 AM
I'm stuck with spokes that are above 5/6 threads (or 3mm) too short using a 3 cross pattern on my front wheel. If I go to 2-cross, will that allow me to make up the difference? Or will I just have to use extra long nipples.
On a standard road wheel with Shimano hub, about 10mm shorter...Quack
Feb 5, 2003 8:05 AM
I noticed your post a couple days ago in the general discussion area and you seem to lack information with regard to how you calculate the lengths. "The Bicycle Wheel" by Brandt has all the information you will ever need to know how you select parts, measure them, and calculate the correct spoke lengths from the info. You can even make Excel spreadsheets to plug variables in and get results instantly.

I don't have the formulas in front of me as I haven't built a wheel recently but where you plug the spoke angle into the formula, a 3x-32spoke wheel will be 67.5 degrees, wheras a 2x-32spoke wheel will be 45 degrees. On a standard road wheel with standard design hub, a 3x wheel would come out around 290mm whereas a 2x wheel would be at around 280mm.

Approaching wheel building without knowing the math (and some physics) behind how they work will end up wasting a lot of time and can cost quite a bit of money. I would go with the book first.

Good Luck!
about what i thoughtniteschaos
Feb 5, 2003 8:20 AM
I've built a few wheels before, but my friends brought me the stuff, they just needed someone who knew how to lace it up. I just was looking for a link or something, guess I need to be more specific next time.
re: Going from 3-cross to 2-cross, how does it effect length?MR_GRUMPY
Feb 5, 2003 9:17 AM
Please post the hub and rim. I'll try to get a 2X answer back tomorrow.
Tubular Mavic Reflex with Ultegra (2002) 32 hole hubniteschaos
Feb 5, 2003 10:40 AM
Tubular Mavic Reflex with Ultegra (2002) 32 hole hubMR_GRUMPY
Feb 5, 2003 11:46 AM
I'll check it out tonight and let you know here either tonight or tomorrow.
re: Going from 3-cross to 2-cross, how does it effect length?curlybike
Feb 5, 2003 1:39 PM
Ft wheel 2x=293.9
Rear drive = 290
rear non drive=292.1
Different answerMR_GRUMPY
Feb 5, 2003 4:53 PM
I came up with 2X = 290mm. You better get a third opinion. Try to call CC. and ask them.
Different answercurlybike
Feb 5, 2003 5:27 PM
Does your calc. put the spoke at the erd or at the bottom of the slot of the nipple? That could be the difference. Mine goes to the bottom of the slot which is about 2mm diff. I bet CC calculated the spokes on the Reflex clincher, not the tubular!
Different answerMR_GRUMPY
Feb 5, 2003 6:12 PM
I was going off an ERD of 605, but now I'm not sure if that was right. I used the spocalc Excl program that is mentioned below. The open pro rims have an ERD of 605 also, and that looks strange. I checked the Mavic website and they don't list the ERD's of their rims. Bummer.....
I also use another site by dhalem, but that site only lists the Reflex clincher. If someone could supply the true ERD of the Reflex Tubular rim, we could get a true answer.
I hate to say this, but there is a good chance that I gave out bogus info. Sorry. I'll try to do some more digging.
I made sure to specify tubular, cause I know few use 'em. (nm)niteschaos
Feb 6, 2003 7:22 AM
Go to this great website...WhoisJohnGalt
Feb 5, 2003 5:36 PM
Niteschaos,
I calculated 290.3 for the front using the "Spocalc" excel spreadsheet found at Damon Rinard's website below. I had the same thing earlier. Had spokes front and rear that were supposed to be for a 3x but were actually sized for a 2x lacing.
Check out the website, do the free download, and have at it. It will give data for 1 through 4x lacing as well as radial for front and rear.
Hope this helps!

http://www.damonrinard.com/spocalc.htm
Tubular vs clincherWhoisJohnGalt
Feb 5, 2003 6:02 PM
Doh!

My calculation was for a clincher. The Spocalc site shows two Mavic Reflex tubulars , both with different erd. One is 613 and the other 616. A 2x lacing would need a 294.3 or a 295.8 according to Spocalc.
I'm not familiar with this rim so I would call CC or even Mavic and get the scoop...
The correct ERD & spoke sizeMR_GRUMPY
Feb 5, 2003 6:27 PM
The Branford Bike website lists the Reflex Tubular rim as having an ERD of 610. After punching that into the spocalc program, I get 292.8 for 2X and 300.6 for 3X.
Please check my work, I don't want to give a bum answer to niteschaos. Thanks to everyone else that caught my goof.
The correct ERD & spoke sizecurlybike
Feb 5, 2003 7:34 PM
I have measured 2 rims and the erd is 613.3 avg., this has the 2.5 mm correction which puts the end of the spoke at the bottom of the nipple groove. Subtract the 2.5 if you need the distance to the point of nipple contact in the rim.This is the data I used to get the previous spoke's length. I also used the actual measured specs of the hub as I distrust unknown sources of data.
The correct ERD & spoke sizeMR_GRUMPY
Feb 6, 2003 7:02 AM
I just found a listing for the Reflex tubular rim that shows 613mm for the ERD. You were right........................................................................
The correct ERD & spoke sizecurlybike
Feb 6, 2003 5:47 PM
I knew I was right for the 2 rims that I measured, now we know that source was right!