I’ve recently bought a double and bash for a new build and a double specific front mech.

The front mech is direct mount and I’m just wondering about height.

Normally I set the mech height to 2-3mm (about a 2p coin) above the outer ring but what do I of now I have a bash?

Do I set it to just above the middle (now outer) ring or as if the bash is the outer ring?

Cheers

I have a similar setup (although not direct mount) and have it set so when in outer ring (old middle) the outer plate on the front mech is as close to the bash as possible.

If you can’t get it low enough you might get a bit of premature chain rub on the bottom of mech when in the granny.

Basically do what seems right… I set mine as tight to the bash as possible, that actually ends up lower than it would with a triple, but I reckon that works better for the remaining rings

I have always had to raise the front derailleur mount slightly when fitting a bash just as dirtydog says above. Shifting usually suffers a little as well. And raising the derailleur may mean that the chain contacts the bottom (horizontal) part of the derailleur cage when in certain gear combos.

You can minimize the issues by getting a bash as close in size as possible to your big ring, such as not using a 40 size bash for a 36 chainring.

As above mostly and as Northwind says – what seems right. I have 2 to fettle now and it’s not always easy. It might need to sit a little higher than you think to get the shifting ramps to catch right.

+1 Northwind and mikesmith. On a dual suss bike it can take a fair bit of riding and adjusting as what works in the stand isn’t what works when your weight is on the bike.

Ok great, cheers everyone.

I’ll set the back up then give the front a go.

I’ll start with it just clearing the bash then go from there.