Calculating Spoke Length for HED Rims - Advice please

[fluroforks]

Having just returned from my LBS i'm somewhat confused.

About a month ago I left them with a pair of HED Jet rims and a pair of m950 hubs and asked them to lace them up for me. Today they tell me that as they can't measure the rim accurately they would have to guess what length spoke to use which could result in them buying in 16 seperate boxes of spokes, which I would have to pay for.

Does anyone here know what length spoke to use with that combination of rim and hub?

 

[JeRkY]

Not sure if it any help but...

viewtopic.php?f=1&t=205499&p=2090270&hilit=hed+erd#p2090270

Thats for a set of HED XC rims...and no I still have not gotten around to getting mine built.

 

[fluroforks]

Could be............

What rims have you got and what hubs will you put them on? It might be worth putting a little production line together.

 

[B3]

There's a technique using 2 spokes, http://www.sheldonbrown.com/rinard/spocalc.htm scroll down a bit to find it

 

[fluroforks]

When I get them back from the shop and give that a go, I just wonder why the LBS didn't do that.

Do you think the Aero profile will affect the calculation much? The spoke won't lie absolutely straight because of it and I don't want to pull the spokes too tight for fear of damaging the carbon. Perhaps im being too soft with it.

 

[syncrosfan]

"When I get them back from the shop and give that a go, I just wonder why the LBS didn't do that." I'm afraid most bike shops nowadays are out for the quick buck and nobody wants to deal with your "ancient" wheels, they'd rather sell you a brand new 10000$ trendy 27.5er or whatever new crap just flooded the market. At least that's the reality here in the LA area, and don't get me started on their utter lack of properly trained personnel doing the maintenance (the horror stories I heard over the years)... That's why my bikes will never see the service department of a LBS, I can do a waay better job than them for the cost of parts and a weekend. Enough ranting about how useless some LBS can be,
I do have a set of HED rims that are laced up to LX hubs. I could take out a couple of spokes and just measure them (assuming that the LX hubs have the same flange diameter as your XTR hubs, which I don't see why they would be different). I need to re-lace them on some NOS Nuke Proof hubs anyways.

 

[fluroforks]

Syncrosfan - A man after my own heart.

My whole life is spent believing you get far better value out of doing a job yourself, you learn more, save a load of money and usually produce exactly what you want and not what someone who wants the easy life wants you to have. With that in mind I don't know why I took them the LBS in the first place. I must have been losing the faith that day.

That would be really helpful if you could measure those spokes, I think theres a few people on here that would be interested to know measurement so this could become a useful resource. Could you also measure the diameter of the hub?

 

[syncrosfan]

I'll take out a couple of spokes this week. One front one, since left and right side are the same, and two rear ones (drive side and non-drive side). Bear in mind that you'll need some nipples that you can torque from the inside of the rim. The ones on my wheels have a hex head on them, I've seen some Titanium ones with a torx head on evilbay, might work a little better than the regular slot ones."Do you think the Aero profile will affect the calculation much? The spoke won't lie absolutely straight because of it and I don't want to pull the spokes too tight for fear of damaging the carbon." As far as this goes, I wouldn't worry too much since the carbon fairing is thin and rather flexible, I would build it up like a regular wheel as far as spoke tension goes. I always wondered whether it would be possible to transplant the fairing onto another rim if the aluminum part of the original ones is dented or too worn out. It is basically just a regular SUN rim with the HED fairing glued on. I'm planning on running Magura HS33's on my bike with those wheels and wonder whether that might be too much power for those.

 

[fluroforks]

Good man, ill look forward to that.

I too have wondered what do if the rim fails, in fact i'm terrified to ride these wheels on the trail at all! If it went together though it must be possible to take it apart. A careful application of heat to soften the glue maybe? I fairly regularly take headlight glass off the casing by sticking them in the oven for 1/2 hour.

Anyway, look forward to reading those measurement. Cheers.

 

[syncrosfan]

Sorry it took me so long but I've been swamped at work! Here are the spoke measurements: Front spoke length = 266mm (3x cross laced on LX hub with a flange diameter of 38mm). Rear non drive side spoke length = 265mm (3x cross laced on LX hub with a flange diameter of 45mm). Rear drive side spoke length = 263mm (3x cross laced on LX hub with a flange diameter of 45mm). Now the front and drive side rear spokes are very close in length so you might be able to use the 265mm spokes for both, I just tried to be as precise as possible when measuring. Not sure how the hubs you want to use stack up in the flange diameter department, but if they are the same you could use those measurements.