headasunder

could someone explain to me the pro's and cons of lacing a 32 hole rim either 2 or 3 cross my latest bike came with grail 3 rims 32 hole laced 2 cross I have broken a couple of spokes(1800km in) on the rear disc side both at the nipple end spokes appear to be the correct length(just cresting the nipple slot) just wondering if 3 cross would have been better or not. Hubs dt swiss hybrid, spokes are double butted bike is a tandem.

Mr. 66

32 spoke count wheels are low for tandem bikes imo, 2x vs 3x is more stress at hubs than at the nipples.

CliffordK

It is pretty common to do 3x for 36h, and 2x for 32h, and probably 28h. Then maybe 1x for lower spoke counts.

It will also depend a bit on the hub selection, so standard road hubs is as above. But, some of the larger IGH hubs typically use fewer crosses.

Part of the choice in number of crosses is to minimize the angle of spokes going into the nipples, and keep spokes coming off opposite sides of the hub roughly parallel.

Andrew R Stewart 

Of course tandems can be much harder on wheels (and tires & chains). But much of the wheels life will be determined by the quality of the build and the riders being supported by the wheels (actually just like a single bike too). I spent 7 years working in a tandem focused shop and would shake my head at the lightweight wheels some teams (or more often, captains) chose for their tandem. But most had pretty good life from Rolf and other low count wheel sets. I attributed this to the team being a smooth, well steered and well communicating team. I don't think 2 or 3 cross has much to do with the OP's issues.

On my own couple of tandems we went from heavy 48 spoke wheels at first to 36 and lighter rimmed wheels with no issues for many miles. DT 2/1.8 spokes, brass nips, Phil hubs and Mavic MA2 rims with 25/28mm tires. Our team weighs about 300+- lbs total.

Personally on a tandem I think less number of spokes is of less difference then on a single. For up the pleasure comes from the time together and not so much the reactiveness of the bike. Andy

HillRider

I've got numerous 32H wheels and they are all laced 3X and I have had 36H wheels laced 4X. These are all factory lacings, not custom, so I think 3X is common for 32H. I have a 24H wheel laced 2x but I'm not sure if 28H is limited to 2X.

Rick

The spoke line coming out of the rim plus the nipple not making full thread contact are suspect here. There could be other problems and as mentioned you probably have low spoke count for a Tandem. You also want to see that there is no space between the flange and the spoke at the bend coming out of the hub. This can cause the spokes to break at the flange. How about some pictures so we don't have to guess.

Bill Kapaun

Max number of crosses is INTEGER(#spokes/9), so a 3X is typically OK on a 28 but barely. Large hubs and/or small rims would probably be an issue though.

headasunder

As stated spoke engagement is good and at the hub end the flange is super chunky(rated for ebikes) and there is no gap, at some stage I will rebuild the wheel on a different rim as I would prefer to run wider tyres than the 40mm optimum stated on stans website. One thing I will say about the Grails is that they don't go out of true much when a spoke breaks as to only 32 spokes it is harder to find 36 hole + rims but lots of choice in the 32 hole range

Bill Kapaun

Is there a "kink" where the spoke exits the nipple that might be reduced going 3X?

Bike Gremlin

I wrote (and added some pictures) about the lacing patterns, the max. number of crosses and why that is important:
Wheel building basics - spoke lacing patterns

TL/DR all else being equal, 32 spokes are better off being laced 3 across (except for the very small rims, where there could be a lot of spoke head overlap).
Of course - build quality and component (spokes, nipples and rims) quality still matter. Probably more than the lacing pattern.
Or, in other words: a good quality build and high-quality components can negate the downsides of a poorly chosen lacing pattern.

Retro Grouch 

Ideally you'd like for the spokes to be tangent at the hub end and radial at the rim end. Spokes that are too close to radial have been known to pull the rim flanges apart. Spokes that are too tangent at the rim end have been known to break at the first nipple thread. Unfortunately, you can't have both so you have to compromise.

davidad

What little experience I have had tells me that the NDS tension was too low. Raising the drive side tension and then centering the rim will raise the left side tension. I had that problem with a 32 spoke rear wheel I built for a 210 pound gym rat. He had a power tap hub and because of the flange spacing the NDS tension was low. Took the DR up to 130kG solved the problem.

oldbobcat

I did a 2x 32-spoke front wheel. I'll never do it again.

Bill Kapaun

Without an explanation why, your post is meaningless.

oldbobcat

The wheel was slightly unstable and exceedingly stiff. It would have been a better wheel had I laced it 3x.

I wouldn't dissuade anybody from building a 2x low-flange 32-spoke wheel, but 3x is an option, and it happens to be the option I prefer.