[Closed] 1x or 2x 10?

The lowest practical 1x solution with 104bcd cranks is 30 on the front and 42 on the back.
I guess you need to determine if that's low enough for you.
You also need to work out if you'd miss the big ring.

Everyone is a bit different on this.

Would I have to buy new cranks? Also would I need a medium or short cage rear mech?

The big ring I wouldn't miss But maybe the Granny ring on big long peaks hills

you could have a 24/38 double and still have same lowest gear

No new cranks as long as they are 104bdc - if they are recent Shimano, then it's likely.

Medium (GS) cage or Long. Short wont work.

You could do the maths.
Your new lowest gear would be 0.71 ratio
Your old lowest gear was 0.66
Your old second gear was 0.75

So your new lowest sits between your current 1st and 2nd gears. Doesn't seem so bad does it?

Busting out the maths!! Clever stuff. Haha.
Yeah that doesn't sound so bad! Is that with a 40t extender?

PS how do you work out the ratios? Sounds handy to know?

Divide the number of teeth on the chainring by the number of teeth on whichever sprocket you want to know the ratio for.

I.e. 30T on front and 40T on rear = 30/40 = 0.75

There's a calculator on Sheldon Brown's website that will do a whole drivetrain at once, just select the appropriate chainrings and model of cassette.

Yeah that doesn't sound so bad! Is that with a 40t extender?

Ahh got it. That's a very handy tool. I'll be using that.

So at the faster end I'll be losing a lot of pedelling speeds.
Old: 42/11- 3.81
New: 30/11 - 2.72

This is where you have to decided wether you want to pedal faster or struggle uphill?

So as for new parts. All I need a narrow wide 104bdc 30t chainring and a 40t extender? Sounds cheap enough to try out and see how I get on!

1x10 is always going to be a bit of a compromise. I had 2x10 on my 456, went 1x10 with a 32 ring and 42 extender. Lost my lowest gear and a couple of highest ones. The gear range isn't absolutely ideal, but having all the gears on one shifter suits me better, and I find I use the dropper post more now that its remote has taken the place of my front shifter lever.

Spend a couple of weeks using just the middle ring on the front. That will give you an idea of what 1x10 is like. 32 front and 36 rear works well for me, regardless of all the maths, I had to use it to decide what I needed.

I've 30T on the front and 11-40 (Hope extender) at the back on a 29er. I struggled a bit at first but I've built up more strength and probably could now use a 32T at the front. There'd be one or two hills that I'd struggle on but it might be something for me to consider.

Yeah i definatly think it the way forward. strip a fair bit of weight off and clutter free cockpit all sounds too good not to try it. prob going to cost around 100 quid but its alot cheaper than going full 11speed!

Cheers guys, been a big help!

i have sram 24/38 chainrings for sale, if you are interested message me!

I'm running a Zesty in the Peaks and North Yorkshire in 2x10 with an SLX 38/26 and 11-34 cassette and also have a Soul with 1x as a 34t and 11-36.

The Zesty is my go anywhere bike. The Soul is running its single ring on an old RF triple.

If going with extenders, be aware that the alu for the 40 or 42 will wear far quicker than the rest of the cassette if used as a regular climbing gear. Think carefully about the ratio choice for the front and be honest with yourself about how often you find yourself in your lowest gear now.

I moved from a bike with 3x9 to one with 2x10 last winter and loved it. During the summer I converted it to 1x10 using a 30T n/w front ring and a OneUp 42T expander ring. I used the above mentioned Sheldon site to work out the closest equivalent bottom ratio to ensure I could get up the same hills. Basically I think it's the best mod I've ever done. The low end is perfect and I don't miss anything from the 2x10 setup and it's great not having a front mech. My new FatBike was 1x10 from the off and again used the 42T expander with 30T front. Would only change it for 1X11 now just to try it but not that worried about the top end.

I had a 3x9 on my old AM bike, swapped it for a 1x9 when the front mech broke. 32x36 and it was great, I was fit enough to get up nearly everything in the lowest gear and no faffing about a front mech. New bike has 2x10 with a 38/24 on the front. Can't say I'm enjoying it. I've lost a bit of fitness and the 24 is too small and the 28 is too big, so finding I'm changing between both rings a fair bit. I think when the winter is over I'll get a 32 narrow wide on it.

I went to 1x10 on my fun bike, was fine whilst i was fit. (32 and 40trex) Today I found out at Cwmcarn that it wasnt enough for me. I had fitted a "secret granny" as a precaution, so I could manually drop to the 24t for long climbing sections. I'm now in a dilema, I still really like 1x, but 2x is probably better for me but the five is limited to 32 on 2x. I've found the 1x range a bit limited, although as I say OK with fitness and/or not big hills. My more cross country bike is still 3x

A big advantage for me is not having a front mech under the swingarm cos its a pig to clean after a muddy ride. Orange problem particularly i think.

arggghhh! this is where im getting picky and confused what to go for now haha. i think 2x will actually suit me better! but i want to try 1x. i might just try it out. if i cant get on with it, ill switch to a double for how much it will cost. but i reckon im going to struggle on a few of the peaks hills where i would have got up them a bit easier on a 3x

I went from a very low 20 (compact drive)/34 double to 1X11. So now have 28/42 (XX1) and my lowest sits between my old 1st/2nd gear, all worked out curtosey of Sheldon Brown..... 😛

So at the faster end I'll be losing a lot of pedelling speeds.
Old: 42/11- 3.81
New: 30/11 - 2.72

This is where you have to decided wether you want to pedal faster or struggle uphill?

Having gone from 3x to 2x in the last few years, I'd go for the better hill climbing gears if you're not using the bike for commuting or the like. I'm on 22+36 rings at the front, and and 11-36 cassette. I've found the 36 chainring a good compromise. By myself, I don't notice the lack of a big ring, and with other MTBers, we're never on road for long, they're running similar setups, and to extent you can make up for the smaller ratio high gears with a higher cadence.

Having this dilemma myself at the moment.

The weight saving and less faff of 1x10 is appealing but the expense of an XT 10 speed cassette + a £40+ range extender in soft aluminium and needing a narrow wide chaninring and then a smaller rear mech etc etc.

I do use my granny ring just so I have a bit of range and I do use my big ring.

I can live with the lower top gear of the 2x10, I don't use the full range all the time. But I do like to go down to 2nd or 3rd to bottom on the 29er (22 front, 34 cassette) and 26" (24 front, 32 cassette).

I really want a 10x1 but I just think I am going to hate the narrow range and the big jump between 36 and 40/42 and the short life of the aluminium 40/42. I wonder if you could make a spider that takes a 40/42T chainring and turns it into a sprocket...hmm