I got a shimano double front mech and am in the process of setting up my Dialled bikes Alpine. The frame was second hand and no shims but I thought I had got the correct front mech size.

Anyway the front mech is a few microns too wide. Is that why you get shims as the DB measurement are different to the shimano ones?

The other thing is that I am having great difficulty setting the front mech up as it will not shift to the big ring. The edge of the front mech is pushing up to the bash ring but the chain has not yet been forced up to the big ring??? I can't work out how it might work unless the bash ring was further away from the middle ring.

Maybe solved the problem fixy suggestion

Will go and try.

The problem was that the double front mech is too short so can't drop onto the bottom and clear the top of the bash. So ironically the shimano double bash front mech doesn't work with my e 13 bash ring

you need the shims to make the 34.9mm mech fit the frame.

you need to position the mech so that when it moves to the middle ring the mech can clear the top of the bash guard by 2mm. you also need to ensure that when in the smallest ring front and largest ring rear, the chain is nearly rubbing the inside of the mech. this will ensure that when shifting up the mech will move the chain.

I bought my Alpine secondhand so didn't know about the shims. Send Mike a sweet email and I bet he'll sort you out if you really want them.

IIRC a perfectly effective bodge is to use one of each of the multi-band shims that Shimano (at least triple FMs) come with. Worked for me.

Never had a problem with using triple FMs anyway. The new double ones just seem a bit limiting, but then I'm a bit of a serial builder / parts swapper 😉

I think it was me who you bought the frame from. I've still got the shims and the hose clips (found them last night)so drop me a mail with your address in Sweden and I'll chuck them in the mail tomorrow.

how would the mech have even fitted the frame without shims?

And Shimano now make mtb double front mechs?

Thanks Glen. I have sent you the address. The reason that I could not get the shimano double specific double front mech to work was that the mech is a lot shorter than the normal one and so I can't get it to both clear the top of the bash and work on the little ring. Will see if I can fix it now.

And Shimano now make mtb double front mechs?

Aye, the SLX one is double-specific (although there's probably an SLX triple one too). It's supposed to allow a bigger jump between chainrings.

cheers stevo!

..and the SLX double-ring one has a shorter cage so you don't rub the back inner corner of the cage on wide rear tyres when you;re in the granny ring 🙂 ..you can def get a different SLX 3 ring one too.