Triplet lacing 8:16 on 32h rim

[ericoschmitt]

I'm thinking about building 8:16 on a DT Swiss R460 32h rims skipping 1 every 4 holes. There are those "Ultra Light Hubs" on bikehubstore at 190g. I'm 61kg.
My concern is the wheel getting 8 jumps for the spokeless section. I've read those G3 rims are actually not round before lacing.

And how do I calculate it? Just get the DS spokes as a 4x lacing lenght and radial x0 lenght on the NDS?

A local mechanic told me the NDS holes would get misaligned and some spokes might be longer than others unless the tension is very unequal. Makes no sense to me.

What about getting the front wheel built with half the spokes, radially (16) on a 32h rim?

Should I get a set of 32h hubs so if everything goes wrong I can relace it? They are some 35g heavier for the set though, and my goal in getting low spokes is to save weight anyway. Just dont wanna waste hubs/rims.

[Mackers]

The front wheel will have all spokes laced to either left or right oriented spoke holes unless you come up with some kind of paired pattern.
Generally seems like a bad idea with such a low spoke count.

You can just use regular spoke length calculators for the rear , you're basically building a 32 spoke wheel, just leaving out half of the nds spokes.

[LouisN]

There's a thread on this somewhere...
I built a rear wheel with a 32h Powertap Pro+ hub on a 24h 38mm Boyd Carbon rim, with straight gauge spokes on the NDS, and CX rays on the DS. Still going strong after 3 years+.
OTOH, the only hub I had some difficulty with tension loss is the BHS UL 190 hub. I won't use this hub again.

Louis

[bikerjulio]

This sounds like a really bad idea on lightweight low profile alloy rims.

[fiziksdrop180]

ericoschmitt, did you end up building this triplet wheel?

I was thinking about doing the same thing, except with a Kinlin XR-31T rim and the Bitex RAR12 rear triplet specific hub (the SL210 Bike Hub Store hub). I've built with this rim and hub (normal 24 hole) before with Sapim CX-Ray spokes. It built up easy and rides great. Unfortunately the NDS tensions are only ~45% of the DS (which isn't too unusual I guess, but a couple NDS spokes were so low they didn't register on the Park Tool tensiometer). For the triplet, I'd use Spaim CX-Sprints instead of CX-Rays to gain some stiffness (according to my calculations, the Sprint is 20% stiffer than the Ray).

[F45]

May I ask why you are inflicting this on yourself? You can buy R460 in 24 holes!

You can get XR31T rims in 24 hole for the rear and 16 for the front. Then the number of holes in the hub will equal the number of holes in the rim. Parity! Amazing!

[TheKaiser]

ericoschmitt, did you end up building this triplet wheel?

I was thinking about doing the same thing, except with a Kinlin XR-31T rim and the Bitex RAR12 rear triplet specific hub (the SL210 Bike Hub Store hub). I've built with this rim and hub (normal 24 hole) before with Sapim CX-Ray spokes. It built up easy and rides great. Unfortunately the NDS tensions are only ~45% of the DS (which isn't too unusual I guess, but a couple NDS spokes were so low they didn't register on the Park Tool tensiometer). For the triplet, I'd use Spaim CX-Sprints instead of CX-Rays to gain some stiffness (according to my calculations, the Sprint is 20% stiffer than the Ray).

On the rim that you describe above, that you built up previously, are you saying that the NDS tensions were only 45% of the DS even with 2:1 lacing? That seems crazy low, given that the whole point of 2:1 is to equalize tension. I know the BHS triplet hubs are not optimized for triplet in terms of flange spacing, but still, that seems terrible.

[TheKaiser]

May I ask why you are inflicting this on yourself? You can buy R460 in 24 holes!

You can get XR31T rims in 24 hole for the rear and 16 for the front. Then the number of holes in the hub will equal the number of holes in the rim. Parity! Amazing!

That is a good idea, although wouldn't that create a problem with spoke/nip angle, or are the R460s not directionally drilled? With a 32h, he would at least have 2 properly drilled drive side spoke exit angles on either side of each non drive side. I'd probably still opt for the 24h and use some combination of a wee bit of diamond file work/polyax nips/internal nips to correct the alignment a bit if needed.

[kulivontot]

I would assume leaving large segments of rim unsupported due to unused holes would result in some kind of stress that the rims were not intended for.
But I am not a mechanical engineer and campy and rolf prima would beg to differ.

[WinterRider]

I'm thinking about building 8:16 on a DT Swiss R460 32h rims skipping 1 every 4 holes. There are those "Ultra Light Hubs" on bikehubstore at 190g. I'm 61kg.
My concern is the wheel getting 8 jumps for the spokeless section. I've read those G3 rims are actually not round before lacing.

And how do I calculate it? Just get the DS spokes as a 4x lacing lenght and radial x0 lenght on the NDS?

A local mechanic told me the NDS holes would get misaligned and some spokes might be longer than others unless the tension is very unequal. Makes no sense to me.

What about getting the front wheel built with half the spokes, radially (16) on a 32h rim?

Should I get a set of 32h hubs so if everything goes wrong I can relace it? They are some 35g heavier for the set though, and my goal in getting low spokes is to save weight anyway. Just dont wanna waste hubs/rims.

Done this.. heads in front 16H (200 lb rider) 1x... that experiment with common 14G spokes. Pounded over RR tracks... potholes etc.. stayed fine and intact. Tension '25 Park'.. or 120 kgf.

The rear 24H finished 105/95 kgf with 1x NDS heads in. That one is still rolling.. on one I moved.

Given reasonable, sound building practice.. skipping the holes is a non issue..if.. one is not kept up at night fretting on marketing issues for nuisances that often occupy space here. Yes.. those nuisances mean something for wheels used near their limits. But in the practical world there hand wringing to market components that feed the builder. That is fine... final cost means nothing to many. But final cost does not determine how a wheel stands.

[fiziksdrop180]

ericoschmitt, did you end up building this triplet wheel?

I was thinking about doing the same thing, except with a Kinlin XR-31T rim and the Bitex RAR12 rear triplet specific hub (the SL210 Bike Hub Store hub). I've built with this rim and hub (normal 24 hole) before with Sapim CX-Ray spokes. It built up easy and rides great. Unfortunately the NDS tensions are only ~45% of the DS (which isn't too unusual I guess, but a couple NDS spokes were so low they didn't register on the Park Tool tensiometer). For the triplet, I'd use Spaim CX-Sprints instead of CX-Rays to gain some stiffness (according to my calculations, the Sprint is 20% stiffer than the Ray).

On the rim that you describe above, that you built up previously, are you saying that the NDS tensions were only 45% of the DS even with 2:1 lacing? That seems crazy low, given that the whole point of 2:1 is to equalize tension. I know the BHS triplet hubs are not optimized for triplet in terms of flange spacing, but still, that seems terrible.

Nah, the 45% NDS tension was for a regular 24 spoke rear wheel with 2 cross both sides. So for the triplet I should get up to 90% with the Bitex hub. Having only 8 NDS spokes scares me though...that's less than one side of a 20 hole front and the bracing angle is less

[WinterRider]

Nah, the 45% NDS tension was for a regular 24 spoke rear wheel with 2 cross both sides. So for the triplet I should get up to 90% with the Bitex hub. Having only 8 NDS spokes scares me though...that's less than one side of a 20 hole front and the bracing angle is less" writes fiziksdrop180

My Bitex is 32H hub 16-8 with 105/95 ratio 3x and 1x NDS skip one hole. Lasers .. started service at 190's wt and down some now.. straight as the day I mounted it. 270 Kinlin rim .. never felt a drop of regard for my safety w 3000 mi on it to date.

Did a 27H 18/9 on 18H rim... after a ride I de-tensioned one NDS radial to see that effect. Did rub albeit somewhat wider clearance for the pads than I regularly run. But even a broken spoke would not meant any problem.

Triplets just IMO eliminate the lazy left side spokes and put the remaining half to work ... bracing angle is more marketing angle than reality for the many that ride. And noted here recently Campy allows riders to 240 lb on G3's... those 14-7's with 3 pair spoking.

[ericoschmitt]

Hi, sorry taking all these months, but it seems I was not "following" this topic and didn't get notifications!

For those rims I ended up getting a set of Record hubs and just laced with 32 wheelsmith DB15 spokes for a bombproof wheelset. 2x front wheel, 1xNDS 3xDS so as not to avoid warranty of the hubs (can't go radial). That wheelset came in at 1580g with Kapton tape already installed, I don't remember where I wrote the weight before the tape. Maybe some 10 grams less? Those rims I got come center drilled. I haven't removed the stickers too, so the set might be at 1560g

Later I got a set of Stans Alpha 340 20/24 laced with wheelsmith DB15 to BHS UL hubs, radial front and planned radial/2x rear. At the time the 16:8 drilling was out of stock... I wish I had waited beause the low NDS tension makes me nervous although I haven't ridden this set yet, still have to finish truing. I said "planned" but my last spoke order was missing the NDS length, I only had 4 of the 12 I needed, and as I live in Brazil it takes a lot of time, money and effort getting things shipped through customs, I usually ask someone to bring stuff when they travel. So I had 8 longer spokes at hand and laced NDS crowsfoot lol. It's a temporary fix, I'm not sure I'll ride it this way, might just wait to rebuild radial NDS. Set weights 1286g with stickers on (rims were 390 instead of 385, so I suppose the difference comes from stickers). I weighted spokes before doing crowsfoot and that only added 1 gram to the rear wheel. DT Swiss spoke calculator had told me this build was going to weight 1233 with revolution spokes, I doubt they are 40g lighter for 44 spokes!

Both wheels have alloy nipples.

In the meantime I got a very very good offer for a set of Zipp Clincher 60 (2013 model) nearly new, some 500km on it maybe. They weight 1820 but are just faster. Aero just beats weight anyway, and my bike was at 6.8kg with those records wheels (with a steel frame a no carbon except for the fork), so at 7.1 now it's not that bad. I guess after getting the correct NDS spokes for the Stans I might just sell it new. There's just one uphill race once a year, took me 1:19:06 last time and I calculated the extra grams only take me 15 seconds, but not counting the aero advantage (8 of the 19km are flatter with rolling hills before the main 11km climb). It sounds kindda useless to keep a lighter wheelset that will offer dubious advantages to race on once a year. Here in Brazil we have ridiculously high import taxes and some other local taxes that make anything cost basically double if you import stuff legally, which I didn't (for my whole bike), so I can probably sell both wheelsets for more money than I spent on parts quite easily and just ride Zipps full time...

Still I'm thinking about getting a set of FarSports 60 or building some FLO rims to get the bike back closer to 6.8 while keeping the aero advantage, and allowing for (safer/easier?) tubeless setup. Both brands have good reviews.

[bm0p700f]

low tesnion is not the issue. the lack of lateral stiffness is. if you have a stiff wheel with low NDS tension then all will be well. Think about it, a stiff wheel does not flex much and the tension loss is smaller so even if the tension is low then the fatigue per revolution is minimal. Using that BHS 2:1 hub means you sacrifise alot of lateral stiffness perhaps 15% (I could work it out exactly) and even thought the tension is higher the tension changes in the NDS and DS spokes will be much higher and bingo spoke failure will happen sooner. Radial stiffness is not affected much by bracing angles. This is not rocket science, just apply logic.

The BHS hubs 2:1 hub will give a less stiff wheel latterally than the standard hub. So your not missing anything.

[ericoschmitt]

low tesnion is not the issue. the lack of lateral stiffness is. if you have a stiff wheel with low NDS tension then all will be well. Think about it, a stiff wheel does not flex much and the tension loss is smaller so even if the tension is low then the fatigue per revolution is minimal. Using that BHS 2:1 hub means you sacrifise alot of lateral stiffness perhaps 15% (I could work it out exactly) and even thought the tension is higher the tension changes in the NDS and DS spokes will be much higher and bingo spoke failure will happen sooner. Radial stiffness is not affected much by bracing angles. This is not rocket science, just apply logic.

The BHS hubs 2:1 hub will give a less stiff wheel latterally than the standard hub. So your not missing anything.

Thank you! Still I'm probably selling those wheels and stay aero. Since I overcooked my weightwheenism, there's no point having a bike below 6.8 for me. Better for the buyer though!

Should I bother swapping the crowsfoot NDS for fully radial before selling, or just true/tension and sell?