Bicycles Network Australia - Australian Cycling Forums

by **kimmie** » Fri Nov 16, 2012 9:43 pm

hi guys,

I have another newbie question... the following information was taken from a Shimano Dura Ace C24 wheel specification:

• High lateral rigidity is produced with a 3 mm offset asymmetric rim and wide flange spacing

My n00b question is, what does it mean with 'asymmetric rim'? does it mean one side's shape is different with the other?

sorry for a st00pid n00bs question... :-(

by **BNA** » Fri Nov 16, 2012 9:52 pm

by **twizzle** » Fri Nov 16, 2012 9:52 pm

Rear wheel. Because the cassette is so wide, the drive-side spokes are almost vertical and don't provide much lateral stiffness, so they move the spoke holes towards the non-drive side to increase lateral stiffness, and it also evens out the spoke tension. Non-drive side spokes are normally at a lower tension and are more likely to fail from fatigue. Other solutions are to run less spokes or radial spoking or thinner spokes on the non-drive side.

Sent from my iThingy...

by **kimmie** » Fri Nov 16, 2012 10:07 pm

Thanks twizzle...

so that means, the 'spokes' on the drive-side will have different length then those on the other side? wouldn't that means instead of shaped like a perfectly symetrical flying saucer (seen from a side) with the rim being in the centre (symetric), it shaped *sort of* like an umbrella?

sorry but it still beyond my comprehension how that shape can be useful as a bicycle wheel....

twizzle wrote:Rear wheel. Because the cassette is so wide, the drive-side spokes are almost vertical and don't provide much lateral stiffness, so they move the spoke holes towards the non-drive side to increase lateral stiffness, and it also evens out the spoke tension. Non-drive side spokes are normally at a lower tension and are more likely to fail from fatigue. Other solutions are to run less spokes or radial spoking or thinner spokes on the non-drive side.

Sent from my iThingy...

by **A_P** » Fri Nov 16, 2012 10:16 pm

this explains it
http://bhambicycle.blogspot.com.au/2008/12/dish-bad-off-center-rim-good.html

by **kimmie** » Sat Nov 17, 2012 4:28 am

it does!

Thanks A_P! :-)

A_P wrote:this explains it
http://bhambicycle.blogspot.com.au/2008/12/dish-bad-off-center-rim-good.html

by **biker jk** » Sat Nov 17, 2012 1:23 pm

The drive side and non-drive side spokes are actually the same length (302mm). I presume Shimano builds the left and right hub flanges to ensure the spoke lengths are equal. Probably reduces costs as well.

by **kimmie** » Sun Dec 23, 2012 6:11 am

Hi all,

Further question re: this wheel.

How can I convert this wheel as tubeless? Do I need a special tyre too, or can my old tyre (Michelin Pro Race) be used? What sort of things I need to purchase to convert it to tubeless?

Apologise for the n00bs questions.

Thanks heaps.