Bicycle Mechanics - Mavic Open Pro 4CD measurments

Hey all,

I am trying to laced a Shimano Deore XT 6 bolts disc front hubs to mavic open pro 4CD, I used DT SWISS spokes calculator it said I need 294mm and 292mm spokes. However I have laced my wheels with those spoke-lenght, the spokes is too long.

Then I find serval calculator but still give me the same spokes lenght. Is it true that old mavic open pro 4CD have different size compare to the new one?

Cheers,
Dubbo.

PS: I have experiences lacing other wheels, just this hub/rims combination frustrated me abit.

Mavic's predecessor to the Open Pro was the "Open 4CD", not the "Open Pro 4CD" and they were different rims, probably with different ERD's.

Mavic's predecessor to the Open Pro was the "Open 4CD", not the "Open Pro 4CD" and they were different rims, probably with different ERD's.

mmmh sorry it was a typo, I meant OPEN 4CD, used serval calculator give me 294 and 293, but those spokes were too long...Kinda frustrated me abit.

I remmber OPEN 4CD has tubular version, would clincher ERD be different??

Damon Rinard's web site's SpoCalc.xls gives the ERD for the Open 4CD as 608 mm and Open Pro as 605. It has no listing for an Open 4CD Tubular rim and I don't recall there ever being one. Mavic did use the name "Reflex" for both clincher and tubular rims.

Damon Rinard's web site's SpoCalc.xls gives the ERD for the Open 4CD as 608 mm and Open Pro as 605. It has no listing for an Open 4CD Tubular rim and I don't recall there ever being one. Mavic did use the name "Reflex" for both clincher and tubular rims.

Yes u r right the SpoCalc.xls give me the 608mm answer but when I calculated give me 294 and 293mm spokes but it's too long. I have some search on other site it said MAVIC Open 4CD (blue/yellow) has ERD of 605mm.

And I was confrusted and measure the diameter by hand it gives me 603mm, thats mean my rims Shrunk???

And I was confrusted and measure the diameter by hand it gives me 603mm, thats mean my rims Shrunk???
No, it means rims vary a bit even within the same model. That's why most wheel building sources recommend measuring your rims and doing the measurements at several place around the circumference.

You can have your current spokes threaded down further and trimmed to the correct length by any LBS with a good spoke threading machine.

ahh thanks alot...now you have cleared my queries.
Just wanted to know what is the best way to measure the ERD??

speaking of old Mavic rims, check out this dinosaur of a website:
http://www.bikepro.com/products/rims/mavicroad.html

My first pair of Open 4CDs (in about 1992) were the first anodized rims I had, and I thought I was a TOTAL PRO!! :p

My first pair of Open 4CDs (in about 1992) were the first anodized rims I had, and I thought I was a TOTAL PRO!! :p
I had a pair of Open 4CD rims on a '96 Litespeed and they were my first pair of really high-line rims too. They were also a bit fragile and the brake track of the rear rim wore through and cracked in just under 12,000 miles. I've used CXP-33 rims since and they've lasted over twice as long on the same bike.

No, it means rims vary a bit even within the same model. That's why most wheel building sources recommend measuring your rims and doing the measurements at several place around the circumference.

You can have your current spokes threaded down further and trimmed to the correct length by any LBS with a good spoke threading machine.

5mm is a huge disparity. To get a 5mm change in diameter, the extrusion would have had to be more then 15mm off. That's just not likely. More likely is that the spec data used for the rim is wrong. Did the ERD come from Mavic?

I believe the ERDs in spokecalc are donated measurements from users that have the rims.