Wheelbuild question
 

Background: I bought 24/28h Formula hubs (RB-68 / RB-210) and 27mm Kinlin/IRD rims (xr-270) from the group buy and intend to lace them with Sapim cx-ray spokes. These will be race wheels, not daily training wheels.

Two questions:

First, does anyone know the official ERD for the 27mm (xr-270) rim? I've found both 588 and 586 via a google search; it's not listed on the IRD website.

Second, how would you lace the rear wheel? 2x or 3x for 28-hole? What cross number would you use for calculations with 28h, 2x or 3x? Would you consider radial NDS to shave a few grams (remember, race wheels)?

OK, so that second question turned out to be several questions...

Thanks for the help,

Mac

586mm

I like building my 28h wheels with 3x drive side and 2x non drive side. The tension is a bit more even then a straight up 2x/2x. Only problem with 3x on a 28h rim is its tough to replace spokes if you break them (but still doable). I would not recommend 3x/3x because of this (you usually break nds spokes because of the lower tension and the spokes going slack) Second option I would do is 2x drive/ radial nds

This was my original preferred lacing, for weight savings if nothing else, because I'd like to keep the wheelset below 1400g if possible (it'll be close) and call it my "race" wheelset. You think that rim and spoking will be sturdy enough for that purpose? I'm about 165lbs.

Mac

I would lace the rear wheel 2x on both sides. I don't like 3x on a 28 spoke build because it usually goes a bit past tangent, which causes a few problems: hard to replace a spoke, and the spokes rubbing the heads can grind the spokes there.

As for the NDS radial lacing, you're talking about saving around 5 grams. The cost of that 5 gram savings is even more tension required on the drive side. At least the 3x/2x recommendation above would even out the tension, but I still vote for 2x both sides.

edit: That being said, if you still want to save that 5 precious grams, I don't think 165 is too heavy for 2x/radial. That is a sturdy rim and 28 spokes is a good number for a mid weight like you.

Don't do 3x.

2x DS, radial NDS.

Radial front, heads in.

TIGHT.

Come to think of it, that rear hub is the one with that weird "dog bone" spoke holes, right? I wouldn't radial lace anything on that hub because the spoke holes aren't equally spaced. As for caclulating the spoke lengths on that monstrosity (which is the primary reason I didn't jump on the buy), didn't the seller offer to help people calculate it for them?

Yup, that was the plan for the front

Yeah, I don't see any reason to cross the front spokes on a race wheel unless you're a clyde or a tandem team.

Sorry to butt in, but why would a 3x on the DS be bad in this case?

Some 28 spoke 3x builds go past tangential, causing the spokes to rub against the spoke head of its neighbor spoke. That can cause the spoke head to grind down the spoke, making if fail. It also makes it a pain to replace a broken spoke since you have to remove the neighbor spoke just to get it out.

If this is the hub I think it is, 3x would PROBABLY be fine since the spoke holes of the crossing spokes are actually further apart than they would be on an equally spaced hub. I would still stick with 2x just to be safe, though. It's plenty strong, especially for a 165 lb rider.

Thanks, I see what you mean by past tangential now. OT, what do you think about doing a lace to 32H to a 32 rim and using all the spokes on the DS and half on the ND? This was recommended to me the other day, but I am not really sold on the idea. Any thoughts?

I entertained that idea once with a 36 hole hub and rim, and even the idea of lacing every other hole on the front of a 36 (so 18 "paired" up front, 27 "G3 style" in the rear) but agreed with others that unless it was because I had the parts laying around, it wasn't worth trying.

if you do the rear nds radial, do it heads in

2to1 done right, works well.

Sun R3.0
http://www.sun-ringle.com/contentpag...wheelsets.php5

http://www.ligerowheels.com/technical/technical.html

http://www.fulcrumwheels.com/jspfulc...=en&world=road

Yes it is, I wasn't thinking about that when I was talking radial NDS... maybe just 2x/2x now that I consider that.

Mac