Originally Posted by
Cypress
New wheelset = new seals and grease in the bearings.
New seals are draggier than old worn-out joints. New grease is stickier and more plentiful than in old hubs. Heavier wheels will also spin longer, but I don't know the specs of either wheel you have. Also, the wattage losses seen in hub drag is next to nothing, so unless it bothers you, I suggest you pull the Shimano hubs apart, clean them up, and put a small amount of lighter grease in them.
Here in the PNW people cling onto Chris King hubs like they are a gift from the almighty himself. I had them on a MTB build once and was amazed at how draggy the sealing system is. Spin down tests on new CK hubs is shockingly bad. Like, legit 7-8 seconds.
I always found the stuff that shimano uses in their hubs, even DA to be on the tacky side and not very slick feeling and always replace it with finishline white lithium grease for something faster, there is a noticeable spin difference.
As for CK, even broken in they tend to fail the unweighted spin test, don't know if its just the design of the races but they do terribly in a truing stand spin test. On the pavement is another story. I worked for a shop that had a nationally ranked BMX team and some of the kids really loved the CK hubs and some of the naysayers pointed to the spin test as proof they were over rated. We did a weighted test on the road swapping just wheels, so same bike, cog and tires, weighted the CKs always coasted further. I typically out coast anyone with me, partially due to gravity having a greater affinity for me, though I'd assume wind resistance balances some of that, while the hubs just seem to spin forever. Other positive was recently overshooting a turn and riding through a puddle created by a tree falling over, don't know how I didn't flip the bike but the water was almost completely covering the stanchions, and I don't feel the need to worry about water getting in.
Originally Posted by
burnthesheep
120rpm on a 53/11 is 45mph. You all coasting down hills at faster than 45mph?
Either way, at those speeds if you do reach spinout on your drivetrain and reach terminal velocity then your aero resistance is vastly vastly more important than a half or one single watt in the wheels. That, and your body weight for going downhill.
Yes, don't you? Best ever was 70 according to the speedo, coming down a 4 mile descent called Petersburg Pass on the NY MA border. Even blew past a couple cyclists I knew who were only doing 55mph. I'm older and not as foolhardy but still consider 55 down large hills/small mountains where I know the roads to be quite reasonable.