ahultin

After a catostrophic rear wheel failure I discovered that Astral is offer a voluntary replacement of their Leviathan tandem wheels. These wheels shipped on the commotion stealhead. Astral states they are not appropriate for combination of tandem team weight and width of tire that is being run on them . We were running a 700x37 schwalbe marathon supreme. I suggest anyone running these contact them for replacement.

https://astralcycling.com/pages/leviathan-service-notice

jim_pridx

Wow! That looks dangerous!

conspiratemus1

Max tire size advised is/was 32 mm and pressure for that size 80 psi.
https://astralcycling.com/products/leviathan-wheelset

ahultin

The stealhead SHIPS from co-motion with 45mm tires (and still shows as such on their website )and the leviathan tandem wheelset

• Wheels: Hand built Astral Leviathan/ Co-Motion Boost 148/110 thru-axle wheels
• Tires: WTB Riddler 700x45mm

rocknrollin

Yikes, that looks scary! I hope you did not get injured.

Did you carry any luggage on the bike? And whats the team weight?
The pictures dont look confidence inspiring to even run 32mm. I would have thought wider tires provide more cushion and damping for the rims, but it looks like the tire pulled the rim apart laterally. I assume you ran tubeless?

jim_pridx

The first couple of photos look as though a hard impact may have caused the initial damage. I'm just curious to know if this was sort of a gradual thing or a sudden impact of some kind? It also seems odd that Co-Motion would spec out a wider tire on a rim that's not rated for it. Hopefully this didn't cause any injuries.

ahultin

No there was no impact. I have had velocity ailerons with a similar failure mode though less extreme. What appears to occur is the cracking on the inside spoke bed as shown in photo 3 from the pressure pushing out on the brake bed of the rim. When the crack gets long enough the sidewalls of the rim blow outward.
In this instance there were two distinct explosions heard. The first sounded like a .22 gunshot followed one rotation later by what sounded like a .223. I assume the first was the crack getting large enough that the spoke bed opened up, the second I assumed was the tube getting cut by the jagged edge of the rim which then peeled the sidewalls out like an onion.
And no, no injuries. This occured at an ideal time in the ride as we were on a class one bike trail with about a 2° incline not traveling very fast. Had it occured 15 minutes prior it would have been during a 50mph descent , that could have been disastrous.

jim_pridx

Thanks for the explanation! In 35 years of tandeming, I've never seen such a thing. Thankfully you had no injuries.

ahultin

Replacement wheelset arrived today which i have to commend them for a very quick turnaround. The hardest part of the process was finding a shop with a wheel shipping box they would give or sell me to send the wheels back.
visually, the new wanderlust rims appear less robust but it must be a stronger extrusion. I though it interesting that they also replaced the spokes (old ones were silver, new are black)
The steelhead will go back together next week so we shall see how these fare.

reburns

It looks like you are running 37mm tires? Curious what pressure you use. Spinergy recommends max pressure of 72 psi for 37 mm tires on their rims, as an example.

ahultin

We were running 80psi at the time. We will be experimenting with a little lower this go around .

Russatiad

I did the replacement as well. After roughly 100 miles the wheels are not true anymore. Sending them to the shop for proper spoke tension. Please let me know how yours work out. BTW We run tubeless and typically run between 32 and 42 PSI.

bwebel

Looks like the rims have different diameters, so the new spokes were probably necessary. If I were replacing a rim after something like that, I'd probably put new spokes just to be on the safe side in any case.

Carbonfiberboy 

Wow! That pressure on a 37mm tire should not have caused any problem at all. Just bizarre. Max sidewall pressure is 85 for those tires and any good rim should easily take that. Your weight should have nothing to do with this sort of rim failure. Schwalbe says 100kg/tire. Their 42mm tire says 80 lbs. max and 110 kg. That width and pressure would put even more force on the rim, yet tire manufacturers are very careful not to spec any tire/pressure combo which would cause failure in a normal industry-quality rim. So something is really, really wrong here.

I would never, ever put those rims on any bike!

The fact that Astral themselves admit that their rims are not up to even normal bike use is well, quite astounding. I've run rims with much higher stresses on single bikes for decades with never a failure like this. This is a serious engineering screwup! I'd take both sets of rims to a machine shop and have them miked for material thickness. If the material is even similar, I'd junk the rims and spokes and put on something known to be reliable.

BTW, if that had happened to you on that descent, you'd have a heckuva good legal case.

Folks on here can suggest reliable rims. The Velocity NoBS rim looks like a good candidate for your application. https://www.velocityusa.com/product/rims/nobs-622

Russ Roth

Any more information on that? I've got 3 pairs of them on my bikes and have really liked how they build up and the ride quality. They're on our gravel and cross bikes, although the gravel are usually only inflated to 65-70 the cross sometimes gets a 27c with 85psi.

ahultin

the ailerons that failed on us where running 650b x47 wtb horizons @55lb and 650b x 42 shwalbe marathon supremes. According to velocity they rarely run into this failure mode on the aileron but we were running at the top end of its tire capacity and top end of weight. As I recall , three had failed before they offered up the cliffhanger as a replacement which we have had zero trouble with (though they are much heavier) I still have a set of 700c ailerons on our newer tandem which seem to be doing fine but i also have run no larger than a 32 on them.