jonwvara 

As I noted, the spokes I have are way too long to lace 3x. And the wheels on the old Gitane were 4x. I'd prefer to stick with 4x--I see no advantage in switching to 3x at this point.
JV

jonwvara 

As I noted, the spokes I have are way too long to lace 3x. And the wheels on the old Gitane were 4x. I'd prefer to stick with 4x--I see no advantage in switching to 3x at this point.
JV

Al1943

I'm really surprised that there is that much difference in spoke lengths between 3X and 4X.
On my first build I accidentally bought spokes for a 2X build but built the wheels 3X 36 hole, only a couple of threads were showing on the non-drive side.

Not sure whay you've tried so far but be sure to initially thread the nipples on only a few turns and then gradually bring the tension up. Double check the lacing pattern.

I prefer Jobst Brandt's instructions for spoke lacing, but Sheldon Brown's should give the same results.

Al

vpiuva

My Spocalc from a couple years ago doesn't use the A & B measurements you refer to, but your wL and wR don't fit either the 120mm or 126mm Campy HF hub measurements, but I ran yours vs. the programs numbers and it matters less than 1mm, and I got numbers near 300mm like you did. So I suspect the ERD may be an issue. Mavic's web site didn't have any info, but Nashbar lists the ERD as 606mm, the Open Sport, a new rim, doesn't appear in my [older program's] listings. There is a footnote, however, for the Open Pros that says that Spocalc adjusted Mavic's listed Nipple Seat Diameter by 3mm for the nipples to get ERD. I'll bet Nashbar is listing Mavic's NSD, not the right ERD, and if I use 609mm in Spocalc it adds about 2mm to the length of each spoke. Only a guess at this point. You may want to get out a tape and measure the rim yourself - remember to add the appropriate rim thickness and nipple shoulder height to obtain the ERD.

By the way - what model Gitane? I bought an Interclub new back around 1972 - wanted the TdF but didn't have the $. Now I own a TdF, outfitted more like a Super Corsa - Campy NR.

jonwvara 

Thanks, Al. I did bring the tension up gradually, and the lacing pattern is definitely correct. I suspect that I screwed up with Spocalc somehow, although they could conceivably have listed the wrong ERD for my rims. I doubt that my hub measurements could have been off significantly.
JV

jonwvara 

Thanks for the info. It does seem that maybe Spocalc's ERD was off. I'm not surprised that the hub dimensions don't appear on the site--they're 37-year-old Campy hubs--not sure what model, they were original equipment on my 1970 TdF. I bought it new that year for, I think, $190 or something like that. It's a great rider--sat in my attic for years until I had it repainted and did a bunch of other work and got it back on the road. It's not exactly all original--in fact, the only original part on it is the headset (plus the hubs, if I ever get these wheels built).

At this point, I don't need to measure the rim, since I can see that the spokes are 2 mm too short. I'm tempted to add 3 mm, but that might be pushing it too far.
JV

BikeWise1

As a wheelbuilder, I'll add something to this. If you are building with alloy nipples there is NO room for error on spoke length. The spoke must go completely through the nipple, but not protrude more than a couple of millimeters when finished with the tensioning process. The reason for this is that the alloy nips rely on the spoke somewhat for strength. If the spoke stops before it is completely through the nipple, you are relying on what is essentially a thin aluminum tube, and there is not enough aluminum to take the tension and they will break. Brass gives you a lot more wiggle room.

I would not build with 4x unless you have a high flange hub.

Spoke lengths aren't like horseshoes or hand grenades....close don't get it!

vpiuva

Glad to see you getting the old TdF back on the road. Kind of hard to see, but my avatar is Gitane's seattube decal from that era. Bought my Interclub at Mel Pinto's in Falls Church, VA. Mel was the east coast importer for Gitane then, and had a few retail shops around the DC area. They wanted $225 for the TdF in '72, just a little more lawn mowing money than I had.

waterrockets 

One more thought... did you measure the spokes to see if they were the correct length?

jonwvara 

Good question! I didn't measure them. I guess I'll get a spoke ruler when I order the new spokes and double check the new batch. But now that I've used these too-short spokes, I obviously own them whether they were mis-shipped as to length or not.
JV