Banzai

A friend of mine wants me to build him an 18 spoke Aerohead front, and 24 spoke Aerohead OC rear. Right now I'm considering, but I have doubts. I've built wheels with that low of spoke count before, but I've used either Kinlin Niobium 30s or Velocity Deep-Vs. It's my belief, having not done any math to back this up, that the deep section of the rims makes them better able to withstand the stresses placed on them by such a low spoke count.

Ordinarily, with a rim as shallow as the Aerohead, I don't dip below 28 spoke.

Having expressed my doubts, he says he won't blame me if it fails...but he doesn't want the deeper rims.

Whether he blames me or not doesn't change the fact that I don't want to build a wheel that I have doubts about. I also don't want him to go to the LBS for this build...the wheels he would get there won't be built to even half the quality that I make.

Thoughts? Can the Aerohead withstand such a low spoke count?

Banzai

No one?

kostyap

Go with your feelings. Do not build it if in doubt

mvMcfly

You might be better served to post this in the Bicycle Mechanics Forums

urbanknight

Agreed. I wouldn't be comfortable with that build unless the rider weighed less than 120 lb and I knew my tensioner was very accurate.

Remind your friend that Aeroheads usually weigh in around 420g, so going with the deeper, stronger XR-300 rims would only be 80g heavier.

aloysius

I wouldn't ride those wheels and I only weight about 140. Obviously, there's a risk of wheel failure, but even putting those concerns aside, wheels like that aren't much fun to ride, imo. The flex while climbing hard and feel disconcertingly vague and wonky going back down especially when you lean into turns on fast, curving descents.

thirst

Maybe he won't blame you if it fails, but maybe his family will when it collapses suddenly and he is injured.

Why 18? 32/3X/ftw!

thirst

Banzai

Yeah, that's kinda what I thought. Like I told him, with those rims I'd go 32 3x for the rear, and no lower than 28 radial for the front. Maybe 24 front but that would really exceed my comfort level.

My own Kinlin Niobium 30s have demonstrated that even at 18 spoke they can withstand tire bursting botched curb hops after a few too many beers (don't ask) but, again, I only do that build with a deep section rim.

My own Aeroheads are built 32 3x both wheels. (I know, the front is a little overbuilt...) The rear is DT revolutions non-drive and Wheelsmith DB14 drive. I'll just need to talk him into that...or sell him my set at a discount so I have an excuse to build more for me!

Banzai

PS:

His opposition to the deep alloy rims is that he feels the metal must have been extruded awfully thin to achieve those cross-sections at that weight. Not something I had considered before, but I suppose something to think about.

Perhaps my first encounter with a stray flying rock into the side of my XR-300s will tell the tale...

ridethecliche

Ask him to check the cross section of his frame.

AEO

I'd be able to ride that. Then again I only weigh 60kg.
I would build it crow's foot front and triplet laced rear.

triplet rear means you don't have to rely on an OCR rim to have closer tension values between left and right since there's 8 spokes on NDS and 16 on the drive side using a 32h hub.
crow's foot front, just because

Retro Grouch 

Can you even buy an 18 hole Arrowhead? Maybe the manufacturer knows something that you and I don't.

"Good judgement comes from experience. Experience comes from bad judgement."

Retro Grouch 

How utterly illogical!

He feels safer stretching the engineering of something that wasn't designed for a specific use than using a product that was.

AEO

apparently you can, but I've never seen one for sale.
but one can just go for using half of a 36h rim and hub.

700c
Non-machined Colors: Black, Silver, White, E. Red, Yellow, E. Blue, Purple, Gold, Orange, Lime Green, Ti. Grey, B. Silver, Pink, Celeste
Non-machined Drillings: 28, 32, 36
Machined Colors: Black, Silver, White, E. Red, Yellow, E. Blue, Purple, Gold, Orange, Lime Green, Ti Grey, Pink, Celeste, Sid Blue
Machined Drillings: 18, 20, 24, 28, 32, 36

Retro Grouch 

That might cloud my judgement.

I wouldn't use half the holes on a 36 hole hub and rim because that would be obvious "use other than intended by the manufacturer".

If the hub and rim both came with 18 holes and that's what the buyer wants and the build is within any restrictions published by the hub and rim manufacturer, I might rely on the "superior knowledge" of the manufacturer and do it.

If he wants pink, however, I'd make him pay extra. Got to have some standards.

AEO

I'm just saying it's possible. the cheaper tiagra/105 hubs from shimano only come in 32h and 36h. they're really good for the money, but if you want low spoke count with those, there are only a few workarounds, one is using 18h from a 36h and the other is triplet laced 24h rear.

if it comes in 18h, and you can get the same rim in 36h, then the 36h rim, while slightly weaker than the 18h, can be built with half the spokes as long as the eyelets aren't staggered.
The rims from velocity are the same thing no matter what drilling, it's just up to the person using the computer to decide what drilling it will get.

the hub, as long as it accepts radial, can be built with half the spokes.

Vireo

Blah Blah Blah Blah

I built a set of 20 Front, and 24 Rear Power Tap wheels on Aerowhead and Aerohead OC rims respectively. I originally built them for Brandy but since it is a wireless 2.4 hub I have been using it on a couple of my bikes that I don't have wiring harnesses on. They were her everyday wheels before I started using them. I am currently using them as my everyday wheels. I use them for commuting and fast group rides. I weigh 150 lbs and have a max sprint between 1100-1060 watts consistently (I know paltry ) . They currently have over 6,000 miles without truing or spoke breakage.

My other Power Tap wheels are 24h front and rear Velocity Deep V's. They have over 30,000 miles on them and have been trued a few times (because I'm anal) but have never broken a spoke. I even used them on Trans Iowa a 320 mile gravel race and didn't need any truing when I was done. Granted they are a stiffer wheelset than the Aerowheads but they come at a cost -- harsher ride and heavier by 200 grams in rim weight.

Banzai

This is exactly why I'm questioning my judgment right now.

My gut says "no"...but like you said, it would appear that the manufacturer endorses this as a build, based on the drillings they offer.

As far as the color goes...yes, one must have standards.

Retro Grouch 

I'd want the customer produce the 18 hole rim and hub. My bet is that'll end the discussion.

Even if an 18 hole drilling is advertised, finding one might be another matter. An 18 hole rim isn't the same thing as using half the holes in a 36 hole rim. The 36 hole rim will have some additional material drilled out of it and the holes are drilled at an angle so half of them are going to be wrong. The same is true of the hub. A 36 hole hub is going to be quite a bit weaker at the flanges because of how closely together the spoke holes are drilled. You're going to want to use more spoke tension due to the low spoke count too.

The more that I think about this, it's more of a stretch than I'd want to do. If any part of the wheelbuild fails, even if the user isn't hurt, your reputation as a wheelbuilder will take a hit. I think that you've got more to lose than you have to gain.

AEO

actually, the aerohead has all eyelets straight down the center with no staggering or angling at all.
it's a pretty basic rim, the drilling is quite crude in that the shavings are left over.

first thing with the aerohead is filing off all the burrs and poking off the left over shavings.

as for the 36h flanges, if it's rated for radial, it should be ok.

Retro Grouch 

How about on the inside? I could pull off my tires and peel back the rimstrip to check but I'm pretty sure the inside holes are offset which tells me they were drilled at an angle.

Banzai

True. The inside is drilled at an angle.

At least my 32h ones are. I assume the rest are as well.

Banzai

He already found an 18 hole Ultegra hub, just like mine on my Kinlin front wheel, rated for radial lacing.

I assume if Velocity says the Aerohead is available 18h that he can order it...

Ex Pres 

YOU GUYS HAVE NO CONFIDENCE

My single speed boasts an AC Micro58 front hub 18s laced to an 18h Velocity Aerohead, laced radially, and a 24h older AC freewheel hub laced to a 24h Aerohead, not even an OC, laced Radial/2X.

The only issue I have had is that I used aluminum nipples (for the bling) and now at 3 years of age they are starting to pop. I relaced the rear w/brass just last week.

And I'm a slug at 195#

AEO

hmm, my 28h didn't have a noticeable offset on the inside.
the only thing I really noticed was how poor the drilling quality was. shavings and burrs left all over the place.

18h I'd be surprised if 18h wasn't rated for radial. only two ways to lace 18h. radial or crow's foot and both require radial spokes.