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Hi all,
Coming from a 2x10 I can see the benefits of 1x12, but the budget version of the Eagle misses the 10 tooth thus being short by about 50% of the 500% range of a bog standard 2x10 - my chain ring is 30th but seems to be the smallest SRAM make for this groupset - is it possible to get a 28? I'm off to the Sierra Nevada soon and am thinking about installing my 2x10 groupset, but would like to keep the minimalism of the NX if possible. Any ideas?
Cheers,
https://www.superstarcomponents.com/en/raptor-chainring-sram-boost-direct-mount-narrow-wide.htm
28t available here.
But if it's the 10t you're missing, a smaller chainring moves things in the opposite direction - you need a bigger chainring.
Ahh? So more teeth at the front equals lower gears? I am basically looking to get a proper granny gear.
Cheers,
This is a useful site - lets you compare different setups.
A quick comparison shows that NX Eagle will give you an easier granny gear (even with a 30t) than a standard 26-38 2x10. It's roughly equivalent to having a 22t chainring with an 11-36t cassette.
The trade-off is at the other end of the range.
28/50 is a tiny gear.
If you need a better climbing gear (granny) you need a bigger rear cassette and smaller chainring. The 10t gives you a harder/faster gear.
Smaller ring (less teeth) on the front & larger sprocket (more teeth) on the back will give you a better granny gear.
A 28tooth ring on the front will give you an easier climbing gear if you change nothing else.
You mention that NX has no 10tooth sprocket on the cassette, but that is at the 'going faster' end of the cassette, rather than the 'spinning fast, while going slowly uphill' end of the cassette.
What chainrings and cassettes were you running on 2x10? You can then work out what size chainring you'd need to replicate the 2x10 granny gear on the NX cassette.
If you go for a smaller chainring you'll get a lower granny gear but also lower top gear - the 10t on other Eagle cassettes helps offset that.
What gearing is your 2x10? 30/50 gives you a lower gear than 22/36.
I'm so confused - basically I can't change the cassette but I can change the chainring - do I need a smaller ring (i.e. 28) or a larger (32+) at the front to get a lower gear* i.e. one to go up steep hills on.
* lower gearing means it's easier to peddle and higher gearing means harder to pedal/faster on the flat right?
I’m so confused
You need a smaller chainring at the front to get lower gears. Your current gear is already lower than any standard 2x10 setup already though.
No, Martin said that to get the equivalent of the 10t at the back you need a larger chainring.
Was it a typo when you wrote (my emphasis):
he budget version of the Eagle misses the 10 tooth thus being short by about 50% of the 500% range of a bog standard 2×10
Plugging a 2x10 XT (36/22 chainrings) and a 1x12 SRAM NX into gear calculator http://gear-calculator.com/ and it shows a very slightly lower gear on the 1x but the 1x is short by two ratios at the top end.
Here's the link to that comparison -
Just doing the calcs manually: 22/36 = 0.611 for the 2x10 and 30/50 = 0.600 for the 1x12. In this instance a lower ratio is better, i.e. it's easier to pedal up a hill.
28/50 is a tiny gear.
But not quite as small as 22/34 used to be on a triple.
But not quite as small as 22/34 used to be on a triple.
Christ that site is hard work on mobile. I stand corrected.
I've got 2x10 and been toying with putting 11-42 cassette on it for super steep stuff. I'm not convinced there's much it would help me get up, but then again that's applied every time a bigger cassette has come out since I was riding 3x8 22-32-44 11-28. 🙂
@philjunior - TBH once you get down to the ratios being talked about above then gradient and surface material are going to have more of an effect on whether you'll get up a particular climb. A gear ratio of 0.6 on a 29er is 17.4 gear inches, you are getting to the point where you are nearly trackstanding.
Also I find that it's often better to be in a slightly harder gear anyway, especially if there's a tricky section as it gives you a bit more momentum to get through it. My hardtail is 1x10 with 30t chainring and 11-42t cassette. I'm rarely in the bottom two gears here in the Dales but there are some climbs where I do need them and some climbs where even if I had 28t-50t I wouldn't get up them.
@whitestone it's true that sometimes your lowest gear isn't the right gear for a climb, or particular sections of a climb, but sometimes it does just become a matter of keeping the pedals turning. I've thought the same about low gears but I'm running lower than ever and still find the odd climb that really tests the legs in bottom gear. I remember one climb that I spent about 25 minutes riding flat out in bottom gear (22-36 on a 29er). A 30-50 would've been welcome, as would any other lower gear.
A friend with a fat bike does use an 11-42 with a double, I think I would do the same if I had a fat bike, I can see a couple of climbs would become doable with that, but yeah most climbs I lose traction rather than totally running out of legs.
As alternative to using a website, front ring size / back ring size * tyre outer diameter = gear inches, which you can use to compare across any bike.
Nominal MTB sizes (26 27.5 29) are near enough, 700c is near enough to 27 (a bit smaller in reality but fine for rough comparison) or you can use the gear chart at the back of the BC rule book (and various other places).