Need advice on improving this lacing arrangement

LukeZ

10 µW
Joined
Apr 11, 2022
Messages
6
Hello all. I've recently laced up my first wheel, it's a front hub Shengyi SX1 motor on a DT Swiss 27.5 rim. Spokes are Sapim 13-14g single butted.

Because the hub is relatively small and the rim relatively large, I chose to do a 2-cross lacing. Here is the setup from the Grin Spoke Calculator that I used:

Fullscreen capture 4112022 85802 PM.jpg

However I now have the infamous spoke clicking that has been discussed many times. I've checked the tension with the Park tension meter and that looks good so it's not inadequate tension or a spoke here or there that is loose.

Looking at the lacing the spokes have a rather tortured route to follow, and the spoke heads are really pulled out of straight with the hub flange as a result, especially on the side of the hub with the greater tension (disc brake side). Here are some pictures to show what I mean:

P1050882_1.jpg
P1050874_1.jpg
P1050878.jpg

The Grin spoke calculator more or less assumes you are going to lace the spokes all on one side of the hub flange in order to achieve the best tension ratio. Indeed, the significant offset of the flanges on this hub are a challenge. My current ratio is about 70:30 which is the best I can get.

I'm wondering if the arrangement I've chosen is at all workable. If not, I have two options as I see it:
1. Change to single cross lacing, so the cross happens happens a little farther away from the hub flange
2. Alternate shoulders in/out on the hub flange as is more typical.

Or I suppose I could do both...

#2 would certainly avoid the extreme spoke bends, at least where they cross, but would result in a worse tension ratio (not to mention needing a larger collection of spoke sizes). Already it is not really possible for me to get my wheel centered in the fork, that would require either not enough tension on the "low tension" side or way too much tension on the "high tension" side. Right now my wheel is offset to the "low tension" side (non disc-brake side). My wheel runs true so I don't think a little lateral offset matters much, but I worry about making it worse.

#1 should help but I don't know if it will help enough.

I was hoping someone with more experience than me could chime in if they think the current lacing is really too contorted and what might be my best option to improve it.
 
Aren't you supposed to lace the leading spoke opposite of the trailing spokes?
One set laced to the outside, the other to the inside.

I recently laced a 2 cross wheel on a Kindernay Hub, and the leading spokes are supposed to be laced from inside the hub to the outside of the flange, while the trailing spokes are laced from the outside of the flange to the inside of the hub.

That enables them to cross cleanly

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Grin's guidance for single cross is all spoke elbows on the outside of the hub:
https://youtu.be/3OialWggZJo?t=106

Justin says the same in general applies to two cross, and that there is no advantage to alternating the elbows when it comes to hub motors, but if there's interference with the freewheel/cassette/chain rubbing the outside elbows on the drive side, to use inside:
https://youtu.be/0HjQb-tqehE?t=704
 
leading spoke first cross should be in front of trailing.... then the next ( leading spoke) cross should be behind the trailing. Always.
 
Scrambler you're right, alternating in and out is the usual method, but as E-HP says Grin's advice is to put them all on one side of the flange or the other in order to improve triangulation. In the video E-HP linked to, the example is given of a wheel with a tension ratio of 70:30, which he says isn't that great, but by placing the spokes on a different side of the flange he was able to improve it. That was the example, in my real-world case, 70:30 is the best I can get, it only gets worse if I change flange sides.

Dipstick, you say leading spoke should be in front of trailing - but what is "in front"? It might be more clear to say which should cross to the outside versus the inside.

I suppose going back to the beginning, does anyone else think it is a problem that I have such extreme bending of the spokes, and such poor fitment of the spoke heads into the hub (at least on the brake side)? I don't have much experience so I don't know, maybe that's normal and I shouldn't worry about it.

But if it's not normal that settles the question about whether to change it, then it's just to decide what would be better.
 
LukeZ said:
I don't know, maybe that's normal and I shouldn't worry about it.

I don't see a big problem. If you ride it, and there's no issues, then you save yourself a lot of work. If an issue develops, then you just deferred when you do that work. I'm guessing you won't have any problems, unless you feel more tortured than the spokes, out of empathy. :confused:

On the remote chance that one of the spokes with the first cross inside breaks, it may be slightly more work to replace.

I might have a different opinion if it were a 5kW hub.
 
Ha ha, I'm probably not that empathetic! It's mostly the interminable spoke clicking when I ride that is driving me crazy. Having then examined the spokes I began to doubt whether I had done them correctly, but since I have no prior experience I wasn't sure.

At the very least I guess I could change to single cross but leave the spokes arranged as they are in order not to worsen the already badly uneven tension ratio. Maybe it won't make any difference but for my sanity it might be worth a try.
 
LukeZ said:
Ha ha, I'm probably not that empathetic! It's mostly the interminable spoke clicking when I ride that is driving me crazy. Having then examined the spokes I began to doubt whether I had done them correctly, but since I have no prior experience I wasn't sure.

At the very least I guess I could change to single cross but leave the spokes arranged as they are in order not to worsen the already badly uneven tension ratio. Maybe it won't make any difference but for my sanity it might be worth a try.

Well for me, I looked at every picture I could on ebike hubs and used every spoke calculator before trying to lace mine. Looking at your pictures, and it doesn't even matter since the holes are evenly spaced, but my eye was trained by looking at pics, is how your first cross happens relative to the flanges. Purely visual, but in every pic of those scalloped type flanges I've seen, the first cross happens with the two spokes on that flange. Might drive me nuts to look at it, but still not enough to motivate me to do more work LOL. Like I said, yours are evenly spaced holes, so only visual.
Crystalyte_Detail.jpg


I laced my hub, then rode it around with some clicking, then did some tightening about two or three times after that, and it eventually went away. The videos all had some different techniques to get the spokes to all seat, and one of them was just the lazy route I took. My clicking only happened when taking off though. :x
 
Your problem is using cross-2 lacing when you should have used cross-1 or quasi-radial. All-same-side lacing works with radial and cross-1 patterns, but that's all. Cross-2 kinks the spokes at the first crossing.

There's no benefit to using more than one spoke crossing when lacing a hub motor. There are drawbacks and problems, though.
 
Thank you Chalo, I'm glad to have some official confirmation to what I suspected. I am going to redo it with single cross.

And thank you E-HP and the rest who chimed in, I appreciate it. HP I hadn't noticed the grouping by flange but now you mention it I won't be able to unsee it!

I'll report back later as to how this all turned out.
 
I promised to report back with the results of re-lacing. I got new spokes and nipples, dis-assembled the wheel, re-laced it using single-cross, and have since put about 60 km.

The ticking remains the same as before. It really gets going over any kind of un-even road surface. If I am riding on freshly-laid brand new pavement I can go a while without any sound, and think to myself, "It fixed itself!" but the first grain of sand we encounter, back comes the ticking.

I've tried increasing the tension on the spokes gradually. The low side is now sitting around 1100 N, the high side at 1700 N. That's beyond the rating of the rim on the high side, but much lower and then the low side has to come down so much to get the wheel centered that it seems really inadequate. I am not at all a fan of the severely off-center flanges of the Shengyi motor.

Anyway, I guess I'm just going to ride it as E-HP did his, and hope it goes away someday. If by some miracle it does, I'll report back on that too.

A picture of the bike, in repayment for those who offered suggestions.

Bike_Chateau_de_Duingt.jpg
 
I laced my Shengyi much the same way as yours but using spoke head washers and I don't get clicking. With a mix of steel spokes and alu hub I'd be reluctant to just live with the noise if it doesn't settle soon. Cool bike BTW.
 
Thanks Anthony. I looked at the hub and it does seem that washers certainly wouldn't hurt. I can't hardly bear to think of relacing this for the umpteenth time but it would be worth it if it resolved the clicking. I'll post back again if I manage to make an improvement.
 
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