Psimet2001 

There's a ton of great options in that area. Some of the shops are legendary and have great talent. I am sure I know wuite a few builders in that are but nothing is ringing a bell at the moment.

Shimagnolo

I build my own wheels and have been using Velocity rims exclusively on 3 bikes for years. (Synergy, Aerohead, A23).

On this page Velocity says 110kgf to 130kgf for tension: https://www.velocityusa.com/tech/rims/

Well, after getting cracking at spoke holes after 2-3 years use, I've dropped to 100kgf, and haven't had one crack since. Note that all these rims are 32H or 36H, and I am 180#.

terrymorse 

Clarification: It is the stress cycling of the spoke tension from every revolution of the wheel that leads to fatigue failure of an aluminum rim.

Fatigue failure is a fact for any aluminum part, since aluminum does not have a fatigue limit. Put it through enough stress cycles, and any aluminum part will break. It's the designer's job to make sure it doesn't fail within its expected time of use.

Psimet2001 

We seldom go up to 110 and are more in the 100 range as well.

Psimet2001 

Clarification indeed - my point was that without tension on the spoke there is no cycling of stress. Good to run into you out here. It feels like forever. Hope all is well!



Indeed - that's what I am trying to say in one of the posts a few back. Not just the designed but also the builder understanding this. Also most of the people who build wheels do so from an "instructional" standpoint. They do what they were taught. They don't understand what's going on with the materials and have no appreciation for any aspect of it other than, "uh the rim company told me I could do XYZ".

I remember calling Matt out at Velocity back when they moved the US and were vetting extruders and I had so many problems. "Are you ISO or QS or other quality system certified? If so can you please send me a copy of your resultant corrective actions?"

frogmorton

I have a 2017 Roubaix and the rear wheel (Axis Elite) broke 3 spokes over the course of two years. At about 5500 miles I just bought new wheels because I wasn't trusting those wheels on a long ride.

Shimagnolo

I'm here in the area, but I've never done work for others before.
I just pinged a couple local guys plugged into the local scene to see if they have recommendations.

Noahma

@Shimagnolo , Thanks! I appreciate it!

ljsense

No one has mentioned the spokes themselves. I can't tell from the photo for sure, but these look like straight gauge spokes. I'd rather have a spoke break before a rim.

Rims need tension to make a strong wheel. It's like building an arch. If a rim calls for a lot of tension, and it's a light alloy, I think it pairs best with a wispier spoke that's been swaged down or, as most people say, butted. This makes the spokes more elastic. When tension increases, the spokes stretch and the rims encounter less fatigue. As the spokes stretch and unstretch, yes, eventually they'll break.

Anyway, great points by Psimet and others -- but I always look at the spokes themselves as a big part of the wheel building equation.

Noahma

@ljsense To be honest, I dont remember if they were double butted or not either. I will have to check my paperwork when I get home. In the past I have just ran with the wheels that came with the bike lol. I am learning a whole ton about wheels now that I have had a failure. I enjoy the knowledge. Thanks!

I contacted an acquaintance that is part owner of a shop and asked him for a few names. I think once I get the bike back I will get a second set of eyes on the wheels to see if they were laced up correctly, and get things modified if necessary.

Shimagnolo

Grip a spoke between thumb and forefinger, then slide your grip from one end of the spoke to the other.
If it is butted, you will clearly feel the transition areas as you slip over them.

Shimagnolo

OK, I just got a recommendation from one of my friends:

Sunny Waas at Velo-Stop here in my town: https://www.velo-stop.com/
He tells me Sunny is building the wheels for Lennard Zinn's custom bikes.

Embarrassing thing is I ride by this shop every time I ride, and didn't even know it was there.
I think it recently moved here recently, and is located on the back side of a light industrial park.

ETA: The shop just moved to this location a month ago.

Psimet2001 

The spokes are actually a much smaller part of the overall process than many realize. They truly just transmit the tension. Their cross sectional size and material composition determine the amount to which they elongate under the load cycle they see. This doesn't translate into an affect on the rim though in as much as long as the tension is carried to the rim then it matters not what shape that tension member is. Think of the degrees of freedom in the connection. It starts to become clearer that it's really just pulling on it (save for some moments caused by torsion/braking).

I wrote what I thought was a pretty good break down on spokes on my site: https://www.psimet.com/blog/spoke-se...icycle-wheels/

ThermionicScott 

You must have missed my post.

Noahma

I just heard back from Velocity, they have determined that the rim was defective and is sending me a new rim and nipples.

Just a personal note after looking back at the picture, it is not showing clearly where the crack started. It started in the horizontal area of the wheel and not at the spoke hole.

I will still get a 3rd party to look at the wheels after they are built just for a piece of mind.

Thanks all for your input, I learned quite a great deal through the experience!

Noahma

Thanks! I will check them out. The wheels do have double butted spokes. I was able to verify it with my mechanic who has the bike at the moment. They are actually very close to where I ride frequently!

ThermionicScott 

Good on Velocity for making things right.

It looks like the crack occurred where the rim transitions between the thick area at the spoke drillings and the thinner walls. There could be a stress riser at that point if the transition isn't smooth enough. But it very well could not be the rim's fault either way.

dmanthree

I took mine back to the LBS who got Specialized to exchange them for a set of Roval SLX 24 wheels.

StephenH

My first "Road" bike was a Raleigh Sojourn and the rear factory wheels did exactly that at about 4,000 miles. Not just one place, but multiple places were starting to crack like that.
Raleigh replaced that under warranty with a different wheel with 36 spoke instead of 32 but lesser rim, and it fell apart after about 500 miles.
I had a wheel built up by a local wheelbuilder and rode it thousands and thousands and thousands of miles.

ljsense

Yeah, I get what you're saying. I know that all a spoke can do is pull.

But if a spoke can stretch a little, be elastic, it won't pull as hard against whatever it's attached to when a force acting on the wheel tries to change its dimensions. You know what I'm saying? Basically, something's gotta give. If the spoke can't stretch, it will try to make the aluminum rim wall stretch.

Some DT Swiss guy said in an interview that their butted spokes -- which they make by forging wire -- have a bit more elastic stretch than straight gauge.

terrymorse 

That's right. Using a more elastic spoke (a double-butted spoke vs a straight gauge spoke) means that the rim is not put through as large a stress cycle (max stress minus min stress) as the rim flexes under load, then rebounds.

Reducing the stress cycle size increases the life of the rim, even though both spoke types produce the same max tension.

bocobiking

See Jim at Vecchio's in Boulder on Pearl Street. He's the shop owner and he's been building wheels for years, including mine.

Chi_Z

that's what happens when they try to squeeze every gram out of the rim, my 480g H Plus Son Hydra is pretty much bombproof