Chainline on a 1 x 9

Struggled with the top gear this morning in that the chain would come off the front. The crankset is set with 2 x spacers on the chainring side. Is this the correct configuration or is it a case of trail and error?

Trial and error, I think there are few if any cranksets designed around a single chainring and large cassette are the moment. Think I’m running a single spacer on both my 1xX bikes.

My spacers are on the non-driveside (2 of them). XT HT2 BB

I would just move the chain line by altering spacers as suggested above. You will probably also need some sort of chain device, I do on my bikes, although I know some don’t. Also consider unramped chainrings like the Renthal.

I’ve altered the chainline on my bikes before as suggested above, although I can’t help thinking that my pedals will be slightly wonky (and therefore inefficient)?

You’ll never notice a few mm.

Running with 1 on drive side, 2 on non-drive side at the moment here, seems better than 2 on drive side where i was loosing the chain a lot to the inside for some reason. BBG bash and that cheap chaincatcher I don’t like, can’t remember the name…

You’ll never notice a few mm.

I would have thought that too. Obviously it’s a bit different but apparently Mr Armstrong would space his pedals to the exact mm, which makes me think that 5mm or so might be inefficient.

http://www.bikeradar.com/gallery/article/pro-bike-lance-armstrongs-team-radioshack-trek-speed-concept-unity-26892?img=17

Cheers guys. Just checked and I’ve got 2 on the drive side. I’ll swap then over and give it a try.

Unramped chainring?

You need a chain device. If you dont have one then your chain will come off!

Unless you’re ‘just’ riding on the road or smooth trails you’ll need some sort of chain device IME

If you don’t back pedal much at all then you’ll probably get away for the mostpart with just a top chaindevice, ie no lower roller/lower guide

Loads of different types of device

TJ, it’s an SS front ring but thanks for the suggestion.

The frame has no ISG tabs so recommendations for a bb mounted chain device?

Thanks again guys.

Measure the distance to the chainring from the centre of the bb shell. Should be somewhere betwenn 47 and 50mm. As already suggested, it sounds more like you need a chainguide.

Have a look on superstar for an idea on some types of chain devices to fit non ISCG tabbed bikes

If you just want a top guide you can get one that clamps onto the seat tube, like a front mech.