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New bike question.

Old 05-22-16, 02:45 PM
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Harvieu25
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New bike question.

Bought a Specialized Allez Elite and it came with Axis Classic wheels. I lifted the front end off the ground and spun the front wheels with my thumb and index finger and it spun for 34 seconds.
I did the same to my Merlin with Neutron wheels and it spun for a full 6 minutes longer...

Is it that much better of a hub/bearings on the Neutrons or are the units on the cheap Allez wheels possibly not adjusted correctly?

I swore to several friends that the new bike tired me out quicker...
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Old 05-22-16, 03:33 PM
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Doug64
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Adjust the hubs and find out.
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Old 05-22-16, 03:39 PM
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Is it possible you're comparing a new wheelset with cartridge bearings to an older wheelset with cup & cone hubs?
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Old 05-22-16, 03:45 PM
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The length of wheel spin has little to do with the bearings, which in fairness, may be the least contributing factor.

First of all new bearings (new hubs, but keeping it general) are more fully packed with grease than they'll retain in service. As you ride the balls push the grease into berms on either side of the track whereby they pick up only a film as they pass by. Grease is highly viscous, so pushing a pack of grease around will make any bearing feel sluggish.

There's also seal drag which hubs without seals don't have, and in those with seals the drag will be reduced with wear.

So you have two good reasons why a new bearing will have more drag than the same one later on.

Now consider the wheel, not only is there hub drag, there's also the inertia based on the weight of the rim and tire, and the aerodynamic drag of the spokes. These are important, because hub drag is a fixed constant applying a given braking force, so the wheel with higher inertia will spin longer (all other things being equal). Aerodynamic drag will drop as the wheel slows, but never goes away completely and can't be discounted.

ow looking at the big picture, the forces involved in how long a wheel spins in your test are miniscule in the scheme of things, (unless something is Very wrong), so even a seemingly large difference is meaningless when considering a bike and rider weighing shy of 200#s. The two factors that most determine drag on a rolling bike are aerodynamics, and tire drag. Small changes in body position or tire pressure can dwarf the seemingly large disparity in the hubs.
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Old 05-22-16, 04:13 PM
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Originally Posted by Harvieu25 View Post
I swore to several friends that the new bike tired me out quicker...
The placebo effect is alive and well.
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Old 05-22-16, 05:20 PM
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Unloaded performance is not a realistic test. The difference you see is likely something as trivial as seal drag or different viscosity grease and will dwindle into utter insignificance when on the road, under load.
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