# 9 speed Cassette for lightweight racing bike



## Bernard3rd (Jun 27, 2006)

Hello lightweight specialists.

I will be building up a lightweight racing carbon hardtail as a racebike. I have a spare SRAM XO 9 speed derailleur and some XO twist shifters I'd like to use. I am debading between two cassettes:

http://www.sram.com/sram/mountain/products/sram-xg-999-cassette

http://fairwheelbikes.com/kcnc-9-speed-cassette-shimano-p-602.html

I would suspect that the SRAM may shift better and is "in keeping" with the other rear components, however, I have heard that this design is hard on the hub driver. The wheels are built on Extralite hubs, and I can't recall whether the driver is made of Aluminum or Titanium...

I would probably prefer the SRAM cassette, but if they are known to shred drivers, then that is a definite consideration.

Does anyone have experience with either or both of these? Of interest to me is shifting performance, durability of the cassette, stress/wear on the driver, and anything else that may be worth mentioning.

Thanks for any and all intelligent comments.


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## IM31408 (Dec 24, 2008)

As far as I know the XG999 uses an aluminum center section holding everything together so it shouldn't have a problem of shredding freehubs, and the Extralite's freehubs are titanium if I remember correctly though I can't say I'm 100% sure. Also the XG999 will last longer and probably shift better and the KCNC doesn't have much of a weight advantage for the downsides it has.


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## Yogii (Jun 5, 2008)

Think about an XTR...


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## rockyuphill (Nov 28, 2004)

The XG-999 is quite particular about the chain that's used, it really doesn't like XTR chain at all (especially on that alloy big cog) but it's happy as a clam with the hollowpin PC-991. It is louder than the XTR, but it does save about 60gms over the XTR 11-32 cassette. 

It's still not easy to find the replacement alloy cog.


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## Bernard3rd (Jun 27, 2006)

*Xg 999*

So then the interface between the cassette/driver on the cassette is made of Aluminum?

Thanks for the info guys, and for the chain advice RU. Helpful stuff.

XTR is great stuff - have it on other bikes, but just not what I want for _this bike.

Thanks again_


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## rockyuphill (Nov 28, 2004)

Most of the torque is transferred through the 32T alloy cog, except for the 11T which threads directly into the freehub. This is what the cassette looks like with the alloy cog removed.


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## Bernard3rd (Jun 27, 2006)

Thanks for the pic RU... How has this cassette worked for you? Shifting performance, wear and wear on the driver?


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## rockyuphill (Nov 28, 2004)

I'm running DT 240 hubs, no wear at all on the freehub splines. I destroyed one alloy 32T cog trying to use an XTR chain, lesson learned. There's been no noticeable wear on the steel portion at all. It is more particular about derailleur adjustment than an XTR cassette/chain, partially because XTR chains are a squoosh narrower than the SRAM 9 speed chains. The additional noise over XTR is the biggest complaint.


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## skyfire1202 (Jan 21, 2008)

What about other chains, 10 speed chains like KMC, Yaban, or Wippermann, has anybody tried any on these cassettes? How did the chain do on the 32T?


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## BeerCan (Aug 29, 2006)

I am using the 999 with dt240 hubs and a kmc chain. I have had zero issues with it WRT my hub or abnormal wear on the 32t cog. now I did bend 2 of the kmc 9sl chains but I think that is a chain issue. Using the 9.99 has been good so far


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## Yogii (Jun 5, 2008)

> but it does save about 60gms over the XTR 11-32 cassette.


Wow so it must save a ton over the XTR 12-34...


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## Mattias_Hellöre (Oct 2, 2005)

For racedays you don´t want to use a KCNC, Soul Kozak or anything with cogs made of aluminum except those from SRAM and Shimano, they are race proven.

I do have Soul Kozak cassettes in stock, 125 grams if I recall right, not for race use I will say.


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## elasto (May 28, 2009)

I am running XG-999 with DT 240s rear hub, Sram X.0 9spd rear derailleur, X.0 gripshifters and KMC X10SL chain with zero problems.


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## Edu24h (Oct 30, 2006)

Where is available the aluminium cog for XG999 cassette?


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