Hi,

Having had a look through this thread again yesterday I'm now convinced that I'm gonna give the 1×9 set up a go.

http://www.singletrackworld.com/forum/topic/1×9-set-up-would-this-stop-the-chain-jumping-from-the-middle-ring

Emailed bonesetter yesterday and he is running a 29t front ring. Given my riding style I think this would work for me but I have some questions:

1. If I run a 29T front ring and an 11-34 cassette can I run a short cage rear mech?

2. If I can't get on with it would I be able to switch back to a double set up on the front (22t & 32t) and still run the short cage rear mech?

3. Will I be able to get a 29t front ring that will fit an XT crankset or do I need to switch to a Middleburn like Bonesetter is running?

Thanks in advance

You could probably "make" a short cage mech work over that range, but it might struggle a bit.

See above. I reckon a medium cage and a chain device/fixed front mech would probably work better.

I think XT cranksets are a standard BCD, so you should be able to find an after market chainring to fit. (Blackspires, TA, Middleburn)

Why not just give the 1×9 setup a go without buying odd sized front chainrings and huge cassettes? Just use what you have now (32/32 I assume)

If you struggle up hills or spin out on the flat then change it. I run 32 fron 28 rear with a road mech and its fine apart from on really steep rocky climbs.

I would go for a medium cage (GS) mech. It will provide enough tension, look neater than a long cage, definitely provide enough clearance for a 11-34, and be more useful if you change your mind or want to sell on.

you'll spin out a 29 tooth ring pretty easily

36 with your cassette choice should get you up anything that's faster to ride up than walk.

won't a 29t need fitting in the inner position and will **** up your chainline.
if you mean short cage mtb mech, yes it'll work with 11-34 and 22/29/33/36

Thanks for all the feedback, it's much appreciated. You throw up stuff that would never even enter my head so your feedback is invalueable.

I have to strip another bike this weekend so was gonna put those bits on for a start. I'm building it up for a couple of solos this year which although rideable in just the middle ring will prob need lower after 15 hours…

Will a 29t need fitting in the inner position & if so how do you get round this screwing up the chainline?

29t will only fit in the middle ring (or outer) position on a 5 arm compact drive spider. 32 is the smallest you can go on 4 arm.

Don't know about the chainline, but you could always run a 32 front with a 12-34 rear if you wanted to lower the ratios a bit?

i run a 1×9 on my 29er

32t and 11-34 – use a super short Sram x.9 mech – works fine and it should just work with a double at the front, though you need to work out the capacity of the mech and get your chain length spot on.

you might struggle to get a 29t ring for the xtr cranks…

sorry, assumed the OPs chainset would be from one of the most recent decades. 😳

Thanks again for the info. The crankset I will be transferring initially is an XT one, so I would need one with a 5 arm compact drive spider. Hmmmm. That's an expense I was hoping to avoid so will give it a go with a 32 + 11-34 set up firstly to see how I go.

Thanks everyone 🙂

you could use a shimnao 12-36 cassette if you are looking for a lower gear

If I was to do that (12=36), would I be OK with a medium cage rear mech?

32t with a 32-11 (or whatever it is) rear cassette works well for me 🙂

I would go for a 11/34 cassttee and either a 32 or 36 front ring depending on your local hlls and prefered cadence.

I have run 1×9 11/34 casettee and both 32 and 36 rings. with the 32 you spin out at a fairly low speed around 25mph so if you have much road work or like to turn the pedals slowly this might be too low – but does give a decent low gear for hill climbing. Using a 36 obviously increase the speed at which you spin out but you do loose the lowest gear.

For me, 32 and 11-32.

I have a fast cadence, and I don't try too hard on roads when i'm on my MTB because I have a road bike for that.

are you on 26" wheels?

then 32 and 11-34 will be fine.

as a note cage length is related to the total difference between gears inc changes at the front – if you look on shim techdocs or sram tech docs if gives maxium sprocket size and capacities for derailluers

Will definitely try a 32t + 11-34 set up before dropping any cash on it as I can steal those off another bike. I just know I split my riding time pretty evenly between granny / middle normally and want to lose as little of the lower gearing as possible.

Bike is a 29er. Believe that will make a small difference, a bit more resistance.

I'm not exactly fit & hardly ever use the granny on my 32/22 double set-up. Eg: Nant-y-Arian, have never used the granny while riding there, or my usual Cannock Chase. You'll get fed-up spinning out at what will seem like a pretty low speed with a 29-34. Guess its down to personal preference, but I'd rather feel a bit of resistance than sitting spinning a high cadence. Probably cos I'm lazy. 🙂