Wheelbuilding Q: Front Disc Lacing Options

[ColonelJLloyd]

I have a front 15x100 thru axle dynamo hub (PL-8X) and as happens with some combinations of dynamo hubs and disc calipers there is spoke-to-caliper interference. Some of the remedies (larger rotor, spacer behind rotor, different caliper, different hub) are, for different reasons, not good options in my case.

The wheel (32h 650b, 567 ERD) is currently laced traditional 3x and is perfectly centered. The spoke interference is slight but it is there. If all the rotor side spokes were head out (elbows in) the spokes would sufficiently clear the caliper. I realize different lacing is not ideal and that front disc hubs are under specific stresses. With that:


Could I lace the wheel 2x or 3x with the rotor side spoke heads out?
Would using CX-Rays help the spokes cross one another better and make a stronger wheel than the current Sapim Race?
Would it help to use spoke washers?
Should the DS be laced the same as NDS?


Thanks!

[CiclistiCliff]

Microshim the rotor outboard. If centerlock, use cassette spacers and snip it somewhere so it slides over the splines. If 6 bolt, Syntace makes shims

[oldpotatoe]

I have a front 15x100 thru axle dynamo hub (PL-8X) and as happens with some combinations of dynamo hubs and disc calipers there is spoke-to-caliper interference. Some of the remedies (larger rotor, spacer behind rotor, different caliper, different hub) are, for different reasons, not good options in my case.

The wheel (32h 650b, 567 ERD) is currently laced traditional 3x and is perfectly centered. The spoke interference is slight but it is there. If all the rotor side spokes were head out (elbows in) the spokes would sufficiently clear the caliper. I realize different lacing is not ideal and that front disc hubs are under specific stresses. With that:


Could I lace the wheel 2x or 3x with the rotor side spoke heads out?
Would using CX-Rays help the spokes cross one another better and make a stronger wheel than the current Sapim Race?
Would it help to use spoke washers?
Should the DS be laced the same as NDS?


Thanks!

1)bad idea to lace all spokes on one side heads out. The bend around adjacent spokes as they cross would be severe and particularly with a disc wheel, may lead to spoke breaks.

2)thinner/oval spokes may help..the bend of the spokes as they crossed would be less, I guess.

2)I lace disc inside pulling rotor side and outside pulling non rotor side.

I think the solution is right above, wee, thin spacers.

[ColonelJLloyd]

1)bad idea to lace all spokes on one side heads out. The bend around adjacent spokes as they cross would be severe and particularly with a disc wheel, may lead to spoke breaks.

2)thinner/oval spokes may help..the bend of the spokes as they crossed would be less, I guess.

2)I lace disc inside pulling rotor side and outside pulling non rotor side.

I think the solution is right above, wee, thin spacers.

Thanks for the reply. As I said in the original post spacing the rotor outboard is not an option.

I understand that its a bad idea to lace with all on one side head out but I can't think of any other options that work in my particular scenario. I'm ok with taking the risk that the spokes will fail over time. I can keep an eye on them. Still wondering what would be the best lacing pattern to do even though this isn't technically advisable.

[R3awak3n]

I know this is also probably not an option you want but I know of people tha sanded the caliper a wee bit to create a bit more spacing. Pretty sure on a SP hub and spyre caliper.

I got lucky and mine works but man, must not be more than 3mm space which bothered me. I went 180mm and now have a couple more mm there which is better.

This is such a bummer. Is this on your new fitz?

[oldpotatoe]

Thanks for the reply. As I said in the original post spacing the rotor outboard is not an option.

I understand that its a bad idea to lace with all on one side head out but I can't think of any other options that work in my particular scenario. I'm ok with taking the risk that the spokes will fail over time. I can keep an eye on them. Still wondering what would be the best lacing pattern to do even though this isn't technically advisable.

2 cross will reduce crossing by one but the first, over-under of the spokes that should be head in, will be the issue. I guess if you have no other option, do it, but I'd lace 3 cross.

But thinking...I'm thinking you could do all the spokes, pulling and pushing, under/over/over...

[Mark McM]

1)bad idea to lace all spokes on one side heads out. The bend around adjacent spokes as they cross would be severe and particularly with a disc wheel, may lead to spoke breaks.

2)thinner/oval spokes may help..the bend of the spokes as they crossed would be less, I guess.

2)I lace disc inside pulling rotor side and outside pulling non rotor side.

I think the solution is right above, wee, thin spacers.

I agree with Peter. Lacing all heads out will cause a sharp kink at the first spoke crossing point. Using thinner spokes will only produce a small increase in clearance, equal to the difference in spoke thickness (if you went from 2.0mm spokes to 1.0mm spokes, you'd only get 1mm clearance). Decreasing the number of spoke crossings increases bracing angle, so going to a 2-cross pattern would actually decrease caliper/spoke clearance.

The real answer is to shim the rotor outward.

[ColonelJLloyd]

UPDATE: Some helpful questions on the 650b list resulted in me realized I had made an error in lacing the wheel. I had failed to interlace the spokes at the third crossing. :crap:

This morning I detensioned the wheel and tucked the outside spokes under the spokes they meet at the third crossing. The outside spokes were the ones hitting the calipers and tucking them behind the inside spokes made them angle toward the hub at a sharper angle and this was just enough to gain the clearance needed.

My eager apprentice took a tumble trying to hand me the nipple driver. Click for video.

https://c1.staticflickr.com/5/4180/33704325643_c2ddab988e_c.jpg (https://flic.kr/p/TmktLP)Untitled (https://flic.kr/p/TmktLP) by ColonelJLloyd (https://www.flickr.com/photos/51002114@N03/), on Flickr

No interference. Phew. :hello:

https://c1.staticflickr.com/5/4170/34353984202_c45bf9f04d_c.jpg (https://flic.kr/p/UkK9Cs)Untitled (https://flic.kr/p/UkK9Cs) by ColonelJLloyd (https://www.flickr.com/photos/51002114@N03/), on Flickr

[cachagua]

Glad you got the good fix on that! I was all set to recommend washers like a few others, but sounds like the apprentice's help saved the day.

I would like to mention that it *is* possible to put the spokes all to one side of the flange, and build a stable, long-lasting wheel. As observed, the overlapping spokes will have to bend over the underlapping ones, but properly stress-relieving that bend will make it as reliable as the much sharper bend every spoke has at its head.

Nearly every rear wheel I've done for myself in the last couple decades, I've built with all the drive-side spokes heads-in. Some of my older ones have an awful lot of miles on them. Number of broken spokes? Zero. I do this to reduce dish, and to move the spokes closer to the biggest cog, to prevent dropping the chain in there and chewing the wheel up (not that this seems to happen much with today's chains and cogs, but I developed a horrible phobia of it in my teens when I was running... uh... a 1X set-up. What was old is new again, huh?).

Anyway, that -- along with the other little rituals I like to do when building wheels -- makes the process a lot fiddlier and slower, and it's not something I recommend to people, especially if you're a working professional. But it is a fact that a robust wheel can be built this way, if you're willing to go to the trouble.