KvnP- try bending it. If it cracks then you'll need to replace it. If it doesn't crack right away you'll want to keep an eye on it. Pad the jaws of your pliers so you don't gouge the rim.


Here's a general wheel building question- when radial lacing front wheels, do you put the heads in or out? I did a wheel on a BHS UL66 hub heads out, because it looks better. However after some 4-5000 miles the spokes started breaking at the elbows. It looks like the spoke holes have a larger countersink on the outside than on the inside. With heads out the spoke heads sit flush to the flange. Heads in and they're 1-2mm proud of the flange. I think lacing heads out on these hubs does not provide enough support to the spoke elbow, hence the breakage.

Does that sound right? I'm building a new set now and doing them front heads in. It's kind of ugly and with the wide SLF71 hub the spokes are WAY out there, but I want these to be sturdy wheels.

Well, maybe try to bend it back. I doubt your going to be able to eliminate pulsing though. Worst case, if bending it back doesn't work, you can always swap over to a new hoop.

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Only certain hubs are can be laced radially in a heads in fashion. It puts more stress on the hub flange to go heads in which is why some manufacturers do not allow for it under their warranty terms. I've never worked with the hub that your on, but it sounds like yours may not be compatible with heads in.
On paper, heads in is going to be stiffer than heads out because you are effectively moving the flange outboard from center just a tad. For all practical purposes though, I would just do the next build heads out.

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@Zen,
he said he built it heads-out.
@KvnP,
weird. like zen described, heads-out is easier on the flange, easier on the elbows, generally. there could be some other things going on, though. the spoke elbows could have been over-(orunder-) stress relieved. like you mentioned, flange shape or width could be less than ideal. could even be simply a bad batch of spokes.
how bout some pics?

The spoke holes are chamfered on the outside but not the inside, on both hubs.

When laced heads out the heads are flush with the side of the flange. When laced heads in, the heads stick out about 1-2mm. I think that the old wheel was breaking spokes because with heads out, the elbow is not supported by the hub. That's where the spokes broke.

It might be that the holes are too large diameter for the spoke you are using allowing some slack in the fit. If so, you may want to re lace with spoke washers under the heads. You don't see it done much anymore, but is an old trick.

I have to say Zen's repsonce and your post Eric did not seem to tie up. I could be the spoke holes are too big for the spokes. What spoke did you use and what was the spoke hole diamter.

I have yet to find a problem with 2.6mm spoke holes and 2.0mm spokes at the bend. Spoke washers might be a solution here but you spoke length will inrease a smidge.

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I can't find the spec but I think they're 2.6mm holes like the other BHS hubs.

You can see the chamfer on the outer edge of the spoke holes but not the inner on the pic here: http://www.bikehubstore.com/SL71W-p/slf71w.htm

The hub I have the problem with is the UL66 but it looks like all the BHS front hubs are done the same way. When I put a loose spoke in the SL71W hub head out there's a bit of play back and forth in the spoke hole. Head in and there's little or no play.

Jobst says if the elbow is longer than the flange width to bend the elbow to an obtuse angle (> 90 degrees) but I have a hard time bringing myself to do that. It seems like spoke washers would be better. I can understand why they'd chamfer the outer sides of the spoke holes and not the insides- can't get the tool in there- but it seems like it'd be better to not chamfer them at all.

I am going to finish the wheel I've laced radial heads in on the SL71W hub and I think I'm going to build a new wheel to replace the one that's breaking spokes, using another UL66 hub but laced 1x heads in. Yea it won't look as cool but you lose all cool points when you're on the side of the road re-truing your wheel to get past the brake pads so you can wobble home.

One little test - soon pictures and review if all stays in one piece

rear Kinlin XR3800 on 18 holes. 12 sapim cx ray 2x cross on DS and 6 sapim cx ray on NDS.
tension was litlle higher on NDS (130kg)
First ride (just quick from test rider) was in good mood

hub Novatec

So you have super aero wheelset with 16 front and 18 rear spokes - rear is superstiff

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It would be nice if those rims in those drillings were easily avilable in the U.k. Kavitor where did you get Novatec hubs in those drillings? Whast is the weight of the XR-380 and the weight of the wheelset?

I did build up a Kinlin XR-300 20F radial and 24R 2x on Novatec A291 and F482 hubs with Spaim CX-ray spokes/alloy nipples this week. It the first time I have done this particular build and I was very impressed with the stiffness of the wheels. 1484g as well. So lighter and alot cheaper than Fulcrum racing 3's. I know what I will be building for my self now for a spot of racing next year.

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I use novatec 24 hole rear hub. On NDS i skip holes (12 holes, 6 spokes)

XR 380 is about 560g per rim

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Questions for you Pro wheel builders - I just had some Kinlin XR-19W rims laced to BHS hubs with 24/28 lasers built by a local shop - as I have yet to enter the wheel building world. I am around 185 lbs and had no problems with old Cane Creek Volos 24/28's, or Campy Zonda's for that matter. Front wheel is great , however when I go to drop the hammer, the rear just dosent transmit the torque to crest that hill or power the flats. They spin fast but I cant muscle my way up a climb like I used to. I guess I should have gone XR-300's but:

I wanted to check spoke tension first - what should the DS and NDS tension be? NDS spokes feel quite low in tension...

Would it make a difference to rebuild with 'Race' spokes instead on both DS and NDS?

Thanks!

I was worried about this problem on these rims. They are only rated to go 105 kgf for max tension, which definitely makes me a bit skeptical. Even if upon the initial build, they were setup to 105 kgf DS, this is still low enough to where I would think the nips would gradually start unwinding.
Go ahead and check the DS tension and make sure it is at 105 or just a tad abobe. For the NDS, you aren't looking for any specific number. As long as your DS is good, and the wheel is in dish, then you should be good to go.
I doubt switching to Race spokes will do much either. If getting the rear back up to proper tension doesn't change the ride quality, you may want to consider rebuilding to the XR270 or what not.

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Thanks! I will get them checked.

I suggeted spoke Mac Aero 424 is the beter than round spoke, alloy nipples fiont and rear, you are light rider.

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