Mr IGH

What advantage do the Lightbike CF rims offer over DT RR411 (435gm/ $90) or even the R460 (450gm/ $40)?

Doge

Weight, aesthetics, sometimes aero/shape. Alloy is more prone to denting while CF cracking - which is worse, but I think the CF takes a bit better hit. On clinchers, I'm not so sure, on tubulars, my confidence is higher.

I think the CF are shaped better in higher profiles.

I had 5 power tap GS hubs built for the team. 3 were on the Mercury rims - like that, 1 was a low profile CF - same weight as the alloy. The other was a 50mm CF clincher.

For clinchers in low profile - I'd choose the alloy.

rpenmanparker 

Interesting follow up on the Light Bicycle wheels I built: All the spokes loosened before or during the first test ride. Looks like a case of extreme compression of the rim by tubeless tire pressure much like has been reported with Stans 340s. Possibly also very gradual compression of the spoke hole nipple seats. I know they were well built and properly stress relieved (several times) before I delivered them to the customer. Spokes are clearly tighter when the tires are deflated. Looks like I will have to retension the spokes with the tires inflated. I will keep you guys posted on this peculiar phenomenon.

rpenmanparker 

So the difference in spoke tension with tires inflated and not was indeed 20% on these rims. Notwithstanding anything I said previously, IMO these rims are disqualified for general purpose applications. There is just no excuse for that.

I ended up retensioning and retruing both wheels to 20% higher tensions with the tires uninflated, then inflating the tires and touching up the true and centering. That last step was very minor. We'll see how it goes when the customer rides them now.

Why the huge loss of spoke tension due to tire inflation? Is it the rim design or a difference in how the internal pressure affects the wheel in a tubeless setup. Dunno, but it seems to me that pressure is pressure. Whether or not there is tube wall between the air and the rim shouldn't make any difference...should it?