The wheels should have come with a bearing adjustment tool, back the adjustment ring off till you have play, then tighten it till you get some resistance then back off a quarter turn. Sounds like the the bearing preload is to high. Ksyriums use sealed cartridge bearings, your Ultegra hubs use loose balls,loose ball hubs usually spin more freely than cartridge...unless of course we're talking ceramics.

 

Freehub drag



Did you have the chain on the cassette with the rear wheel installed? If yes, then you are looking at drag in the freehub. Obviously your bearings should be adjusted properly per coasterbrake, but the most likely thing is just that the rear wheel has a freehub. If the wheel coasts less without the chain engaged, then it could be just thicker grease or bearing seals that need to wear in.

 

Thanks for the replies. Yes, the wheel is fully installed (i.e., chain is on, etc).

The hubs were pretty tight; I backed off the adjustment ring as coasterbrake suggested, and the "spin time" just about doubled right there.

I also did some other Google searching and I discovered that both the Mavic cassette spacer and the Shimano cassette spacer need to be installed; I only had the Mavic spacer in there. Not sure if that made any difference.

It sure seems to spin "smoother" now and definitely takes a while longer to stop spinning. The wheels only have ~100 miles in them so far; we'll see if they break in some more.

 

you do realize that how the wheels spin in the stand doesn't make a damn bit of difference about how they'll roll on the road, right? the longer a wheel spins in the stand pretty much means that the bearings don't have a 'complete' grease fill and what grease is in there is getting pushed away from where it actually does some good. sooooo...you'd rather have them be very very smooth, but have some drag due to grease and seals their job.

 

Interesting... I figured that the work required to overcome any drag from the hubs was so minimal as to not have an effect on the road, but that's good-to-know info regarding what you say about the grease.

 

I like czwrenchs response, makes me want to look at my hubs... My Tarmac wheels will spin for days on end, but apparently thats not necessarily always a good thing to have

 

maybe u tightened the quick release too tight. but i dought its that simple as uve already inspected the wheel thoroughly. maybe its defective. take it to the lbs