Anyone have experience with both these wheelsets?

I want a lightweight wheelset that can be used for long/hilly potentially alp days preferably with alloy rim

I currently run 404’s which are great but have their limitation as my only good set of wheels (I also have some training wheels)

Kind of limited to these wheelsets due to discounts I can get – I can’t get equivalent campag or fulcrum discounted

I’ve had C24 RS81’s before and loved them, currently have Cosmic Elites and I’m very impressed with them too.

Ksyrium Pro Disk user here. I’d get them. Well, I’d get them again cos I’ve already got them.

High end shimano hubs are great to work with now, all bearing adjustment can be done by loosening a 5mm allen key and turning an indexed/detented adjustment ring with your fingers, no more guesswork with cone spanners.

This might seem small beer but I really like knowing I’ve got the absolutely smoothest bearings possible rolling underneath me, and I’m sure I’ve read that well adjusted cup and cone are the best there is. Fulcrum are the same, just greased and serviced a Fulcrum front wheel, piece of cake.

I’ve ridden the rs81s and ksyrium elite extensively and prefer the Shimano myself.

The carbon laminate rim gives such a beautiful smooth ride but still nice as stiff

Is the main difference on the Dura ace just thinner rims?

I had first incarnation of the dura ace wheels they were ace. I’d choose Shimano

I have ridden the Ksyriums for ages. Superb wheels. I also have some DA9000 handbuilt wheels on Mavic cxp33 rims. I’d pick the DA for the hubs. Neither are bad choices to be honest.

Is the main difference on the Dura ace just thinner rims?

IIRC the non series whelsets borrow the rims from the groupset above and the hubs from the one below. So RS61 is the 105 rim on tiagra level hubs, RS81 is ultegra hubs and dura ace rims. So the difference between RS81 and R9100 would only be stuff like titanium freehub bodies (not sure if both are tubeless though?).

Cant afford DA, but my RS61 wheels have been absolutely faultless as my winter wheels despite my less than subtle riding, I’m more of a bunnyhopper than a ride-around-the-pothole-er! I even rode up Aston Hill (the road, not the DH venue) with a rear puncture, the tyre stayed on the tubeless bead and didn’t roll off the whole way up (I think I picked up a bit of flint in the detritus at the junction from the main road).

On the 9100 spec they make a thing out of the rims being just 0.7mm thick, which is not mentioned on the Rs81 listings.

But the 80g total wheelset weight difference could just be in hubs and other bits.

I just got a nearly new set of RS81s anyway, more than good enough for me.