Rotational weight of equal weighing wheels but different depths
#1
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Rotational weight of equal weighing wheels but different depths
A discussion at Superweek yesterday and this question was posed!
Wheel A is 58mm deep and weights 1450 grams
Wheel B is 38mm deep and also weight 1450 grams.
Is rotational weight the same or is it easier to spin up the shallower wheel due to cutting through the wind on acceleration?
Does it make no difference as to depth if their the same weight?
It almost seems like its hard to start a sprint or acceleration on deeper wheels of the same weigh!
Wheel A is 58mm deep and weights 1450 grams
Wheel B is 38mm deep and also weight 1450 grams.
Is rotational weight the same or is it easier to spin up the shallower wheel due to cutting through the wind on acceleration?
Does it make no difference as to depth if their the same weight?
It almost seems like its hard to start a sprint or acceleration on deeper wheels of the same weigh!
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Deeper wheel should spin faster as the mass is closer to the axle. At least that's how I would think it works.
And, does it really matter?
And, does it really matter?
#4
Making a kilometer blurry
Yes, deeper rim of the same weight will have lower rotational inertia.
Think about a sprint: you start it at maybe 33mph, and end up at maybe 37mph in, say, 5 seconds. Do you really think you could feel what race wheels are doing in a 4mph acceleration spread out over five seconds? That's a 12% acceleration, and feeling a <2 lb. pair of bike parts on a 200 lbs system.
Think about a sprint: you start it at maybe 33mph, and end up at maybe 37mph in, say, 5 seconds. Do you really think you could feel what race wheels are doing in a 4mph acceleration spread out over five seconds? That's a 12% acceleration, and feeling a <2 lb. pair of bike parts on a 200 lbs system.
#8
Senior Member
A discussion at Superweek yesterday and this question was posed!
Wheel A is 58mm deep and weights 1450 grams
Wheel B is 38mm deep and also weight 1450 grams.
Is rotational weight the same or is it easier to spin up the shallower wheel due to cutting through the wind on acceleration?
Does it make no difference as to depth if their the same weight?
It almost seems like its hard to start a sprint or acceleration on deeper wheels of the same weigh!
Wheel A is 58mm deep and weights 1450 grams
Wheel B is 38mm deep and also weight 1450 grams.
Is rotational weight the same or is it easier to spin up the shallower wheel due to cutting through the wind on acceleration?
Does it make no difference as to depth if their the same weight?
It almost seems like its hard to start a sprint or acceleration on deeper wheels of the same weigh!
Taller rims tend to weigh more and, generally speaking, across a manufacturer's line, taller rims are more aero (that's the assumption I think that applies to the two rims in question). If the taller wheels don't weigh more they should wind up faster if they're in fact more aero. If they're more aero they'll be much faster at the top end in ideal wind conditions (cross tail I think, and a slight cross head) - the wheel keeps winding up just a bit longer instead of hitting the aero wall.