If I run a 1 x 9 (32T front / 11-32T rear) will I need a chain device? Not got a front deraileur and the frame has no ISCG tabs.

Cheers.

I've been running 1×9 on my OnOne for months without a guide.

Yes. Get an e13 and run a bb mount adaptor plate (comes with them if you're buying new)

I use an e13 LSS ISCG05 – comes with a BB bracket if you dont have the tabs. Costs around £45. Be aware it took me the best part of 5 hours to set it up perfect so it didn't rub in any of the gears – I was using a 38t/11-34t

Just use your existing front mech if need be. Use the adjustment screws to lock it in place and voila, instant cheapo chain device. And if you find you want a granny ring,its easy to sort out without too much faffing. 🙂

If you run a short cage on your rear mech, and the chain as short as possible, you will not need anything up front.

I have been running 1×9 for 3 years with nothing and chain never drops

An unramped front chainring will also help and will last longer and can be reversed.

Usually I'm fine with my 1×9 set up but if I'm somewhere a bit rockier or anything then I can sometimes drop my chain so just ordered a chain device.

I am using the mrp 1×9 device if its rocky or rooty it keeps the chain on, pauls components does a really smart looking one

After riding rough terrain for the first time, I found I needed some kinda device and went for a jump stop and a bash ring.

Lightweight and cheap.