12 speed 11-33 cassette

Triathlon Forum
1

Recently bought a TT bike with SRAM 12 speed, my first bike with SRAM since the Red 10 speed days. SRAM seems fine, but it’s hard for me to accept the 10T cog. If SRAM won’t offer a 12 speed cassette beginning with an 11T, and the new Dura-Ace 12 speed eschews the 10T cog, then I can’t imagine not ditching the SRAM cassette for Dura-Ace. So will SRAM or someone else offer something a 12 speed cassette without the 10T cog? An 11-33 cassette would be awesome for 1x.

Current 10-33 cassette: 10,11,12,13,14,15,17,19,21,24,28,33

‘SRAM TT’ 11-33 cassette: 11,12,13,14,15,16,17,19,21,24,28,33

And if we are going to get greedy, this would be a great alternative for flatter courses:

‘SRAM Flat TT’ 11-28 cassette: 11,12,13,14,15,16,17,18,19, 21,24,28

2

Recently bought a TT bike with SRAM 12 speed, my first bike with SRAM since the Red 10 speed days. SRAM seems fine, but it’s hard for me to accept the 10T cog. If SRAM won’t offer a 12 speed cassette beginning with an 11T, and the new Dura-Ace 12 speed eschews the 10T cog, then I can’t imagine not ditching the SRAM cassette for Dura-Ace. So will SRAM or someone else offer something a 12 speed cassette without the 10T cog? An 11-33 cassette would be awesome for 1x.

Current 10-33 cassette: 10,11,12,13,14,15,17,19,21,24,28,33

‘SRAM TT’ 11-33 cassette: 11,12,13,14,15,16,17,19,21,24,28,33

And if we are going to get greedy, this would be a great alternative for flatter courses:

‘SRAM Flat TT’ 11-28 cassette: 11,12,13,14,15,16,17,18,19, 21,24,28

If you add yet another freehub standard to the mix Campy offers 11-29 and 11-32.

3

Campy 11-32 and 11-34 have great ratios. Especially the 11-34, since only the top two change. Its a close-to-perfect 12 speed cassette, imo

4

A 12-32 would be a great every day cassette. Maybe move to a 12-25/28 for flatter races and 12/34 for the days in the mountains. I’ll trade the grams for the friction and functionality.

5

Does campagnolo cassette works with Sram Red Axs chain?

6

No. SRAM uses a different roller size/spacing, I believe. Not sure about cog spacing. Can’t use anything other than SRAM cassettes.

7

Recently bought a TT bike with SRAM 12 speed, my first bike with SRAM since the Red 10 speed days. SRAM seems fine, but it’s hard for me to accept the 10T cog. If SRAM won’t offer a 12 speed cassette beginning with an 11T, and the new Dura-Ace 12 speed eschews the 10T cog, then I can’t imagine not ditching the SRAM cassette for Dura-Ace. So will SRAM or someone else offer something a 12 speed cassette without the 10T cog? An 11-33 cassette would be awesome for 1x.

Current 10-33 cassette: 10,11,12,13,14,15,17,19,21,24,28,33

‘SRAM TT’ 11-33 cassette: 11,12,13,14,15,16,17,19,21,24,28,33

And if we are going to get greedy, this would be a great alternative for flatter courses:

‘SRAM Flat TT’ 11-28 cassette: 11,12,13,14,15,16,17,18,19, 21,24,28

You could probably run a campy 12s cassette with a campy chain and a non-AXS crankset/chainring. They make a 11-32 and a 11-34.

8

Is having a 16t that big of a deal?

9

It always rubs me as interesting to hear that about the 16t not being important when the tri forums are always about having enough gears to climb at a good cadence and race target power for triathlons.

The 16t is in the meat of your gears used for an event. So let’s say 48t front and 16t at 90rpm on a 25mm tire. You get 21.25mph. Remove the 16t and what are the cadence options for 21.25mph assuming you’re holding power/speed constant? Instead of 90rpm it’s going to be 84.5rpm in the 15t or just under 96 in the 17t.

That’s not dramatic on the higher cadence end, but in the “meat” of my drivetrain I personally find that unacceptable.

It is what it is on bailout gears for climbing to have big speed/cadence jumps to get range. But in the area you spend most of your time riding? I’ll pass. We can fight for my 16t cog.

10

Is having a 16t that big of a deal?

Nahh… I don’t have a 16T on any of my 11sp bikes now, whether it’s an 11-28 or 11-30 cassette. But for those of us who would rather trade a few grams for a cassette that starts with an 11T cog, and if you are giving me an extra gear moving from 11sp to 12sp, then yes, gimme that 16T.

In simpler terms, if you tell me I get 12 gears and then tell me I get to choose between an 10T cog or a 16T cog, give me the 16T all day. It’s a more useful cog, to me at least.

11

The 16t is in the meat of your gears used for an event.

But not really, 16t specifically, though, right? You just mean there’s a range of relatively tight gearing that’s useful for an event. The SRAM 10-33t (presumably the OP likes the big bailout option at 33), has 6 contiguous cogs from 10t to 15t. The Dura-Ace 11-28 or 12-28 have 5 contiguous cogs.

Now let’s say you don’t want to use that 10t much because of low efficiency. Fine. You still have 5 contiguous cogs. You just select your ring sizes to put those 5 contiguous cogs at the gearing range you want.

I could maybe see that a 11-15 range is, overall, slightly less efficient than 12-16.

Or do you mean there’s some absolutely magical gear ratio that’s only achievable with a 16t? E.g. the 89.44" with the 53x16t combo just isn’t the same as the 90.00" with a 50x15t. But, man, you’d have to be awfully sensitive to claim to able to even feel that difference.

I could see an argument that SRAM AXS has no benefit at all for for flattish TT relative to prior generation groups. And I agree (at least until new Blip details come out). But it also, I think, has very marginal detriment.

12

The SRAM 10-33t (presumably the OP likes the big bailout option at 33), has 6 contiguous cogs from 10t to 15t. The Dura-Ace 11-28 or 12-28 have 5 contiguous cogs.

I was using the 10-33 cassette as an example because that’s what came with the Shiv Tri Disc that I just picked up. Also, I run a 54 / 11-28 1x setup now, and I have to admit that I sometimes wish I had something a little easier than the 54 / 28.

Sticking with the 10-33 SRAM cassette, I’d like to keep the 6 consecutive cogs that you note (just shift them from 10T-15T to 11T-16T) and avoid the drivetrain losses from the smaller cogs and chainrings.

13

Rather than add a dinner plate on the back, why not go to a smaller chain ring?

14

I don’t want a 10T cog due to inefficiency. If I’m starting with an 11T cog, then I need a “normal” TT-appropriate chainring, not the 46-48-50 options that admittedly make sense with a 10T cog. For me, that’s a 54. If I’m running 54 1x, then I wouldn’t mind something bigger than the 28 I have on my current 11sp setup. I should probably be running an 11-30, just haven’t gotten around to changing things.

The only reason I can see for the SRAM convention of starting with a 10T cog is to save weight, at the expense of drivetrain efficiency in the smaller cogs. I would rather absorb a few more grams with “normal” chainrings and cogs and regain that lost drivetrain efficiency.

15

FWIW, if found the best set up (for me) on AXS 12sp is a 52t chainring (now available) with 10x33 or 10x30 for flatter courses.

The 52 chainring means I’m very rarely in the 10t and rider more in the middle of the cassette (so more efficient than a 48 / 50), but it’s there to push power on long fast down hills.

Admittedly, I ride with a lower cadence than most - i prefer 70-80 rpm, so happy to grind up hills, and I’m also not fazed with the cog jumps.

The weight differences you speak of would have absolutely no impact

16

On a clean drivetrain we’re talking .75-1W drive chain loss on 10 v 11 with the new chain design. The commonly cited velonews “study” was done by CeramicSpeed and had conflict of interest and poor set up issues.

By going to a smaller cassette, you reduce weight in both the cassette and chainring and have a small, but better (ok tiny, but so is .75 of a watt) aerodynamic profile. You said if you had the option you’d take the 16T cog, well at 80 RPM:

54/16 @80RPM = 21 MPH.
54/11 @80RPM = 31 MPH.

Sounds to me like your ego is writing checks your body can’t cash.

17

It always rubs me as interesting to hear that about the 16t not being important when the tri forums are always about having enough gears to climb at a good cadence and race target power for triathlons.
I understand what you are saying, but in reality I use very few of my gears.
58-12 for flats, 58-23 for the easier hills, 45-17 for almost everything else I encounter. Chicagoland is pretty flat. During Placid and CdA I don’t believe used anything else besides maybe 45-12.

All other gears are pass-throughs.

Trying to dial in a gear on anything but a constant grade seems absurd. Grade constantly changes and shifting has a cost.

I don’t use a power meters so that might be my answer.