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.

 

[wafter]

That doesn't look like a Shimano item; if it's a cheapie may well be that they expect you to fit it with no inserts which I'd certainly not be doing, looking at the inside of that clamp.

 

[Webbo2]

I have only bought one Shimano clamp on front mech in recent years a 105 and I’m pretty sure it was solid on both sides of the clamp.

 

[Vapin' Joe]

That doesn't look like a Shimano item; if it's a cheapie may well be that they expect you to fit it with no inserts which I'd certainly not be doing, looking at the inside of that clamp.

It doesn't look like it to me either unless the inserts are missing and I wouldn't fit it to an aluminium tube.

 

[Dadam]

I would imagine it's designed to take at least one of the adaptors and without them it would indeed cut into the paintwork and probably emboss the tube as well. It needs to be done up fairly tight not to move under cable tension
I upgraded a Tiagra band-on to an Ultegra one and the clamps on both were solid machined castings with a smooth interior face, not what seems to be a cheaper stamped component in the pic above.

 

[Pointy boy]

It doesn't look like it to me either unless the inserts are missing and I wouldn't fit it to an aluminium tube.

It is 100% genuine Shimano… unless Halfords have started selling knock-offs, which I doubt. All Claris clamp-ons are like this, but higher-level group sets are not, and I’m really not sure why.

 

[Dadam]

OK, so I'd say it definitely needs to be used with one of the pairs of inserts. Will it fit with any of them? It doesn't matter if there is a few mm gap where the bolt closes the clamp. My Tiagra one had about 6mm gap when the bike was delivered and it was done up tight.

 

[Shearwater Missile]

I may be a bit late to the party. A shimano FD3400 I took off looked the same as yours. One side is solid, the other has the two ridges. It was hit once in an accident and of course scratched the paint but at least I could see where to put it back. I upgraded the FD and chained to smaller chainrings, consequently I had to lower the FD. All I did was put a couple of loops of black insulation tape on the seat tube to cover up the existing marks.