I've taken the front mech off my commuter with the intention of only using the big ring.

Its still got the middle ring on there but that's only becuase I havent got round to sourcing shorter chain ring bolts.

If I run a single chain ring without a front mech am I likely to lose the chain every time I hit a bump or should there be enough tension to keep the chain on?

It'll come off. Particularly if you leave the big ring in the outer position, as the chain line will be shit!

Prob come off as the cage helps to keep the chain on excpet with big jumps IME 🙂

use the mech as a chainguide

For commuting 1×9 works fine with no chainguide / mech – but you do need an unramped chainring, shortened chain and in the middle position helps.

I have run two bike like this for thousands of miles with no isssues.

For commuting 1×9 works fine with no chainguide / mech – but you do need an unramped chainring, shortened chain and in the middle position helps.

Like this?

Sorry thought you were MTB's on it – I expect it would be OK ulness you go over big bumps and as TJ say shorten the chain 😳

Thats the sort of chappie

So chain came off twice on the way home yesterday. Both times I was coasting over bumpy tarmac at a fair speed.

Decided no chain guide was a bit of a liability so bodged up one using my old deore front mech and replaced the bottom adjuster screw with a longer one and tightened it until the front mech cage was in line with my chain ring, hey presto, chain guide. Quality bodge!