Are they the most underrated part of the bike? I just upgraded my stock Bontraeger wheelset to Velocity A23 rims, White Ind. hubs, and Gatorskin tires. The tires went dorm 23 to 25. Just took a little test spin and it just seems like the bike rolls a whole lot smoother. Is it the hubs or the tires, or a little of both?

Whatever it is, I like it!

you not only changed tire sizes but also rim width and you think that it might be your hubs giving you a smoother rolling wheel???

As mentioned, you changed a lot of things to just think it is only the hub. I notice more of a difference in hubs in the area of engagement then anything else. Let us know how the the whole combo works out for you after some more riding. I am thinking of going to a similar wheels and hubs. If you don't mind me asking, where did you buy them at?

Prowheelbuilder. Took longer than promised, but good price.

I have an A23/WI set from prowheelbuilder, too. Their built price was less than I could source the components for. Took about 2 weeks which is what they quoted.

They seemed well built out of the box. Unfortunately I crashed them after about 300 miles and did have to true them up a bit. But I've had about 2000 trouble free miles since then.

scientific method fail

BF isn't science. It's art.

BF isn't science. It's art. i agree with you. thank you .

It's a bit of everything, but yes, nicer hubs make a difference. White Industries hubs are very nice hubs and will be trouble free and roll wonderfully for as long as you have the wheels. The A23 rim is also very nice. You don't say which model wheel you had, so if it's a low end model, there will be a big difference for sure. However, it's pretty much a given that a nice, well made set of hand built wheels made just for you will always ride nicer than a stock or pre-made wheel that is intended to work for a large variety of riders. If the bike feels good now, just think how nice it will ride once you get rid of those Gatorskins.

Both. 23 to 25, especially with a wider rim, is a big jump and the bike will feel much smoother. White industries hubs are great (I considered them before going King) and may well roll better than the stock Trek own-brand you had, especially if you didn't keep them serviced. Finally, depending on which wheel set you had, you likely have a different spoke pattern and possibly tension in the wheel, which can also impact the ride.

Be sure to keep up with servicing on the new hubs...