Shimano band-on front derailleur question.

[Pointy boy]

This may be a stupid question, but…
I’m about to install a Shimano band-on front derailleur. It came with adapters for smaller seat tubes, but I don’t need to use them as I have a 34.9mm seat tube.
So my question: the front band has a recessed shape (see photo) whilst the the rear band has a smooth face. Won’t this recessed side damage the seat-tube, in a way that the flat/faced side (or an adapter) wouldn’t? Or is this a non-issue?
Thanks!

 

[raleighnut]

What is the frame material ?

 

[All uphill]

If I remember correctly one of the adapters supplied fits neatly in the recess of the band. When tightened only the adapter makes contact with the seat post.

 

[Pointy boy]

What is the frame material ?

Aluminium.

 

[Pointy boy]

If I remember correctly one of the adapters supplied fits neatly in the recess of the band. When tightened only the adapter makes contact with the seat post.

No, just comes with 2 adapters. The clamp is 34.9, with adapters to take it down to 28.6 and 31.8.

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[raleighnut]

Aluminium.

Should be OK as long as you don't overtighten, could have been a problem with a Crackbon frame

 

[Wheelspinner]

I've usually used a small strip of old inner tube cut to fit those clamps to any frame, aluminium or carbon or even steel. Avoids clamp marks to a fair extent and protects paint in the event you need to move the derailleur up or down to adjust for different size chainrings.