Hi,

The current wheels I have are '05 Mavic Ksyrium Elites with 18 radial spokes for the front and 20 2x straight spokes for the back. I find these wheels stiff enough for my needs and I have never had any spoke problem and have not even needed to get the wheels trued in 5 years (I weight about 155 pounds). The only thing I like less about these wheels is the weight (1600g+) and I am looking for a light alternative. From the research I have done so far it seems that the Extralite SPM/SPX hubs are quite good and allow quite stff builds due to the large flange to flange distance allowed by the usage of straight pull spokes (63mm for the Extralite vs ~53mm for my Mavic rear hub).

So I was wondering, should I expect similar stiffness and durability to my Mavic Ksyrium Elite wheels if I get wheels built with Extralite SPM/SPX hubs, NoTubes ZTR Alpha 340 rims, 20 radial spokes for the front and 24 1x (driver side) straight spokes for the back? I would hope that the extra spokes and the extra flange distance can compensate for the lighter rims and the radial spokes on the non-driver side for the back?

Thanks!

Well, you must keep in consideration that the Alpha 340 is definitely a bit on the softer side simply because of its weight. Now, the flange spacing on the Extralite isn't bad, but if your dropping that kind of money on hubs you may as well go with an Alchemy ELF/ORC which has considerably wider flange spacing. This will maximize lateral rigidity even on the softer hoop and at the spoke count you have chosen it will be quite stiff. Now, don't get me wrong about the Extralites. They are great hubs. However, on a softer rim, the wider flange spacing will make a big difference.

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From what I see on fairwheelbikes.com, the ORC as 58.6mm flange to flange spacing, which is LESS than the Extralite SPX (63mm), unless there is a typo somewhere?

Thanks!

My mistake. I was initially thinking of the SX.
Regarding the spacing, it is hard to say exactly. From what we can tell, Extralite is measuring their DS flange on the far outboard side which definitely adds some extra distance. So that 20mm measurement may be a bit off, simply because it is measured different than the Alchemy.
One thing to keep in mind though is the NDS radial lacing will not be near as stiff as alternative patterns. With the ORC, you would be able to lace 2x NDS and make a much stiffer more efficient wheel.

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You will be hard pressed to find more trouble free wheels than the Ksyrium Elites. The 05's that you have are over 1800 grams IIRC. Why not try the new Ksyrium Elites. That are about 300 grams lighter in the area of 1500 grams.

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True but a Stans/Extralite build would easily be at least 350 grams lighter than what you mention. The added aerodynamic benefits of not having massive spokes helps efficiency. Lastly, the Ksyrium is a bombproof wheelset until that rear hub goes out.

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Zen,

The spokes on the Elites are not massive, just decent bladed profile stainless steel. Never actually seen one broken. Now the huge alloy spokes on the SL, etc. - those are just stupid IMO. Can't argue about that super light Stans build though.

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Yeah the Stans/Extralite are 1150g in 24f/28r...

I understand how crossed spokes are important on the drive side for torsional rigidity and how this might help for the flanges used with j-bent spokes (more material in the non-radial directions), but is it necessarily also true for the cylindrical flanges used with straight spokes?

Thanks!

Lots of wheels do radial on the drive side, Zipp, Mavic, etc. I don't think it matters despite what the physics seem to tell us.

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Well, the cylindrical flanges like on the SX will transfer power pretty well. However, the radial lacing that is required on the NDS will have more of an effect on lateral rigidity than power transfer. At higher weights, there commonly comes the problem of brake rub when laying the bike over on a climb.
Another downside to the SLX is that there is pretty much no chance of an LBS being able to do spoke replacements without ordering spokes. Most shops only stock Jbends and you would be damn lucky if you were able to find an SP in the right length.

_________________
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Hi,

I am not sure why you mention the SX and SLX hubs? Why would radial lacing affect lateral rigidity? I would have thought that only the bracing angle would affect lateral rigidity, no? About spoke replacement, I don't really see it really as an issue. I can always order a few extra spokes with the wheels...

Thanks!