Assymetric Rims vs Symmetric Rims - isnt offset an issue?
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Assymetric Rims vs Symmetric Rims - isnt offset an issue?
So I read all the data how assymetric rims offer more stability (up to 40%) over symmetric rear rims. So one would think that assymetric is so much better.
However I am wondering the following. If I take a bike with both symmetric wheels and another with one assymtric rear and a symmetric front wheel, isn't it an issue that the wheels are technically not lined up on the same line but that the rear wheel is slightly off set? Wouldn't that cause issues somehow? Or is that ok and no difference is really felt, since the offset is really quite small?
Would appreciate any thoughts from someone who knows about these things?
However I am wondering the following. If I take a bike with both symmetric wheels and another with one assymtric rear and a symmetric front wheel, isn't it an issue that the wheels are technically not lined up on the same line but that the rear wheel is slightly off set? Wouldn't that cause issues somehow? Or is that ok and no difference is really felt, since the offset is really quite small?
Would appreciate any thoughts from someone who knows about these things?
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The rims are on center, either way. The rear hub flanges are offset way left to make room for the cassette on the right.
With a regular rim the drive side spokes are much tighter because they are at a steeper angle than the left but have to balance the side force. This causes problems. The offset rim’s spoke holes go on the left side so the triangle formed by spokes and hub is closer to isosceles, and the left and right tension are closer to balanced.
You can also put an offset rim on the front to the right to deal with the flanges offset for the brake rotor. But no one has much trouble with front wheels so it’s not enough of a problem to solve.
With a regular rim the drive side spokes are much tighter because they are at a steeper angle than the left but have to balance the side force. This causes problems. The offset rim’s spoke holes go on the left side so the triangle formed by spokes and hub is closer to isosceles, and the left and right tension are closer to balanced.
You can also put an offset rim on the front to the right to deal with the flanges offset for the brake rotor. But no one has much trouble with front wheels so it’s not enough of a problem to solve.
Last edited by Darth Lefty; 04-08-21 at 12:06 AM.
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If a wheel is a bit crooked you could ride it casually and probably not notice.
It is hypothetically possible to make symmetric rims that are in the middle. Just have a spacer on the axle, on the opposite side to the freewheel. You would just need slightly wider frame spacing, or a narrower hub.
It is hypothetically possible to make symmetric rims that are in the middle. Just have a spacer on the axle, on the opposite side to the freewheel. You would just need slightly wider frame spacing, or a narrower hub.
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The rims are on center, either way. The rear hub flanges are offset way left to make room for the cassette on the right.
With a regular rim the drive side spokes are much tighter because they are at a steeper angle than the left but have to balance the side force. This causes problems. The offset rim’s spoke holes go on the left side so the triangle formed by spokes and hub is closer to isosceles, and the left and right tension are closer to balanced.
You can also put an offset rim on the front to the right to deal with the flanges offset for the brake rotor. But no one has much trouble with front wheels so it’s not enough of a problem to solve.
With a regular rim the drive side spokes are much tighter because they are at a steeper angle than the left but have to balance the side force. This causes problems. The offset rim’s spoke holes go on the left side so the triangle formed by spokes and hub is closer to isosceles, and the left and right tension are closer to balanced.
You can also put an offset rim on the front to the right to deal with the flanges offset for the brake rotor. But no one has much trouble with front wheels so it’s not enough of a problem to solve.
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If a wheel is a bit crooked you could ride it casually and probably not notice.
It is hypothetically possible to make symmetric rims that are in the middle. Just have a spacer on the axle, on the opposite side to the freewheel. You would just need slightly wider frame spacing, or a narrower hub.
It is hypothetically possible to make symmetric rims that are in the middle. Just have a spacer on the axle, on the opposite side to the freewheel. You would just need slightly wider frame spacing, or a narrower hub.
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I believe he's talking about putting the flanges closer to center, which is one of the improvements possible with boost and super-boost spacing. The mfgr's don't always do that because they have well-sorted designs for either side of the shell and only want to change the length of tube in between. Looking at Industry 9's hub wheel building dimensions, they are still 6mm offset for super boost, but the total spacing is a lot bigger, which also helps. The single speed hubs are nearly centered. The fat bike hubs have only 3mm offset. Another way to reduce the drive side spoke tension is to make the drive side flange bigger, and they do that on the center lock hubs. Why just center lock, I don't know, but I'm sure there's some clever reason.
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I recently built a set. I used non boost, 135 and 100 qr in fact.
You actually face the rims different directions. Front to account for the disc side, and rear to account for the drive side. The theory is that you don't have to pull the tight side quite as tight, to get a perfectly dished wheel.
I've heard other banter about them allowing you to use the same length spokes throughout. That seems like more of a hub type variable than rim.
The wheels most certainly are not even tension side to side. The only way to get that in my experience is a front rim brake wheel.
That said, they're probably more even than they would be. And the tight side (front disc and rear drive) is not as much tighter than usual.
Will this result in a stronger wheel? Probably. But will it result in a wheel that is so much stronger that it makes everything else obsolete? Not at all.
It's a selling point. Look for the rim you want, width, weight, price, intended use. If they're asymmetrical, cool, if not, cool.
You actually face the rims different directions. Front to account for the disc side, and rear to account for the drive side. The theory is that you don't have to pull the tight side quite as tight, to get a perfectly dished wheel.
I've heard other banter about them allowing you to use the same length spokes throughout. That seems like more of a hub type variable than rim.
The wheels most certainly are not even tension side to side. The only way to get that in my experience is a front rim brake wheel.
That said, they're probably more even than they would be. And the tight side (front disc and rear drive) is not as much tighter than usual.
Will this result in a stronger wheel? Probably. But will it result in a wheel that is so much stronger that it makes everything else obsolete? Not at all.
It's a selling point. Look for the rim you want, width, weight, price, intended use. If they're asymmetrical, cool, if not, cool.