Replacement for the largest cog (32 or 36t) on a Sram XG1099 cassette

[echappist]

I'm thinking of getting either a 11/32t or a 11/36t for some of the climbing races i will be doing next year. I don't want this to turn into a debate into why or why i shouldn't get such a cassette.

Anyways, i've read that the largest cogs on the XG-1099 and XG-1080 are apparently machined out of aluminum, and as such, are quite unreliable. How true is this, and how many miles do you guys get from that cog?

The races where i'll be using the particular cog will have climbs that require it 5x3minutes in a race, 10 minutes in a race, and maybe 18 minutes if i'm crazy enough to do Catskills. Otherwise, i doubt i'll go near it in any race i'll be doing. It's conceivable that i won't need it for more than 60 minutes total, though i guess there's always the chance that i forget and accidentally shift into the largest cog.

Alternatively, does anyone know if there's a company out there that will mill a piece of steel into a cog? I guess if this turns out to be too much trouble i could always just get a Shimano XTR 11/34.

[stien]

If you're in the mood to hack, you might try taking the rivets out of a MTb cassette and stealing the cog you need.

[echappist]

If you're in the mood to hack, you might try taking the rivets out of a MTb cassette and stealing the cog you need.
thanks for the suggestion. only thing is would the largest cogs be separable? i've run Sram for such a long time that i have the impression that the largest 3 cogs are together as opposed to being individual separable. Otherwise a PG1070 would be the easiest route to go

[brenick]

IRD has steel cassettes in lots of sizes

http://www.interlocracing.com/cassettes_steel.html

[zandrrr]

34t chainrings are made of aluminum. I think you'll be fine.

[stien]

thanks for the suggestion. only thing is would the largest cogs be separable? i've run Sram for such a long time that i have the impression that the largest 3 cogs are together as opposed to being individual separable. Otherwise a PG1070 would be the easiest route to go

Some are, I'd suggest Shimano, something older. A 9s cog might be work for you. I know those are out there.

[HillDancer]

I have the 11-36 in Shimano XT. It's a 100 grams more than the 1080, but worth it to me. It is definitely robust, instead of sounding like each tooth is being plucked during a chain move like on the 1080, it's quiet. Shifting is smoother on the XT cassette than either the 1080 or 1070, and a Shimano CN-7901 chain is an improvement over a SRAM chain on many levels.

Whether to use a 34 or 36t low gear depends on the small chainring size and your cadence ability (rpm and smoothness). For me, a gear lower than 1:1 causes my front wheel to wander due to my less than round spin. I would rather shift higher and stand, then use the low gear to recover when the grade lessens.

[oldpotatoe]

I'm thinking of getting either a 11/32t or a 11/36t for some of the climbing races i will be doing next year. I don't want this to turn into a debate into why or why i shouldn't get such a cassette.

Anyways, i've read that the largest cogs on the XG-1099 and XG-1080 are apparently machined out of aluminum, and as such, are quite unreliable. How true is this, and how many miles do you guys get from that cog?

The races where i'll be using the particular cog will have climbs that require it 5x3minutes in a race, 10 minutes in a race, and maybe 18 minutes if i'm crazy enough to do Catskills. Otherwise, i doubt i'll go near it in any race i'll be doing. It's conceivable that i won't need it for more than 60 minutes total, though i guess there's always the chance that i forget and accidentally shift into the largest cog.

Alternatively, does anyone know if there's a company out there that will mill a piece of steel into a cog? I guess if this turns out to be too much trouble i could always just get a Shimano XTR 11/34.

Or a SLX 11-34 or 11-36..doesn't need to be XTR..or even XT.

Trim your nose hair if you are concerned about the 'extra' weight.

[binxnyrwarrsoul]

"Trim your nose hair if you are concerned about the 'extra' weight."

Potd.

I've run 32T and 36T cogs on my MTB's forever, with zero issues.

[HillDancer]

What happens to an aluminum freehub body when using cassettes with low gear sprockets that extend to the freehub body, is the sprockets dig into the splines. The lowest gears have the greatest amount of torque applied; the larger the sprocket, the greater the torque. If left on long enough the cassette/sprockets can be troublesome to remove. It's not an issue with steel freehubs. This is where a cassette with 3-4 of the lowest gears being attached to an aluminum carrier has a service advantage.

[echappist]

Or a SLX 11-34 or 11-36..doesn't need to be XTR..or even XT.

Trim your nose hair if you are concerned about the 'extra' weight.

but that's the voice of reason when i'm trying to be irrational ;)

thanks to everyone's responses.

[HillDancer]

I'm running the XG-1099 now, rear shift quality is outstanding with this cassette, very different than the noisy 1088. While shifting was good and noise low with the Shimano XT 11-36 and CN-7901 chain combo, pairing the 1099 with SRAM's PC 1091R chain has changed my generalized poor impression of SRAM chains; there is an exception. 1099 gearing is slightly different than the XT, I like the closer spaced two high gears of the 1099 and the 16t middle sprocket. The fact the 1099 cassette is 130 grams less than the XT cassette is icing on the cake.

[echappist]

thanks for the update! Do keep me posted on how it fares down the road, especially the 32t or 36t sprocket.

I just realized that the 28t on my XG1090 is also made from aluminum, and it has held up fine through 10+ races this year. Hopefully yours would be in as good of a shape.