Front 1x rings are very cheap at the moment. Get the 11-42 and 32 and see how you get on. If it’s not right buy another front ring.

Out of curiosity how much weight do you think you’re going to save going 1×11 from 2×10?

Sweamrs is still on a 3×9 (XT/XTR) set-up and contemplating an upgrade for her bike but can’t decide what option would be best. We’re doing BCBR as a pair in 2016 and so by day 7 a low gear is going to be very attractive but in the meantime she’s also doing some racing where 28 to 11 doesn’t seem a high enough gear. Could go the switching out front ring route but seems a phaff.

32 is what I use on my race bike with 29 inch wheels . I use an Absoluteblack oval chainring and think it really helps when you are struggling to get the cranks round , in fact wanting to run an oval chainring was the main driver for me to go 1 11 . If you are worried about your high speed gear being a bit low you could consider a Sram casette which has the benefit of a 10 sprocket which will give you 10% more top end grunt , downside is you will need an XD driver .

How do you push hard over the top on flat singletrack ?

Lol.. I’m going a 28t at the front as I like spinning up the hills. Not fussed pushing it that hard on the downs!

I’ve just changed my carbon hard tail from 2×10 SRAM X9 to 1×11 M8000. I did it for a number of reasons but mainly because I couldn’t use the 39/11 so what was the point of having it? I went for a 32 up front which seems ok for now.
I’ve only ridden it twice so far but the ratios seem about right, 32/11 is just about ok – a bit low on a long fast section but how many of those do you get in a xc race?

Maybe I will get used to it but I’m not so keen on the new feel to the Shimano shifters, it feels heavy like scram but not as snappy.

There’s one on the Sheldon Brown site that will give you ratios, gear inches, gear gain, etc.

Kryton57 – I’ve tried both a 2 x 11 and a 1 x 11 set up on numerous occasions and tested all the different combinations of 32, 34, 36 and even 38t chainrings.

My set up isn’t really comparible as I ride a 27.5 XC race bike but I have settled on a 2 x 11 with 36/26 up front and a 40-11 cassette. the only other set up I’d use on the race bike now would be a 38/28 but that all depends on the course.

For example, if the course was a power course (think Thetford), I’d run a 38 so that I have the top end to stay with the 29ers but if it was a climbers course, then 36 is good.

I ran 36/26 on Sunday and didnt once go into the 26 ring but also didnt once use the 11t cassette ring….

After all that, my advice would be to try a few different combinations and see how you feel…get a 2×11 set up and you can always run it 1x anyway….

1x systems are as much about simplicity as they are about weight saving: things getting harder? go down a gear; getting easier? go up one. There’s no having to think: “If I go from this ring to that one do I need to go up/down a gear or two at the back?”. Also, if you run a dropper post then not having the front shifter frees up space on the bar for the dropper remote.

As far as front ring sizing goes: On a 29er HT (mainly ride in the Dales and the Lakes) I started with 30T, when that wore out I moved to 32T partly because I needed a new front ring there and then and the shop didn’t have a 30T. I use the 40T extender a bit more with the 32T, might get another 30T so I can switch back and forth as I require.

In your specific circumstances the only reason I can see to move to a 1x system is reliability as the front mech is more likely to have problems if you change gear when the drive train’s under stress

Is weight saving REALLY all that???

Its probably the kind of weight that can be saved elsewhere on the bike/person…something as simple as tyres, grips, saddle etc and even kit/shoes.

Yes, moving from 1 * 10 to 1 * 11 added weight as I wasn’t prepared to pay for a light weight cassette and the XT one, whilst “cheap” is certainly not light!

I also do the occasional gorrick race and 12/24 hour races. I’m using 1×10 with an expander ring 11-42 and an oval 34 front ring. It’s fine for my local riding in the central south. If I lived somewhere hillier I’d probably drop to 32. As has been said , rings are quite cheap so you could swap depending on the type of race/course.

It is very handy, the visualisation of the ratios & gaps is so much easier than comparing numbers…

My previous spreadsheet is now in the recycle bin…