attaching a front derailleur to a curved stoker seat tube

[norbikes]

Am encountering probs attaching a front derailleur to a curved stoker seat tube. The curve shifts the cage downward towards the rear, so I have to raise the clamp in order for the cage to clear the big chainring. Not a prob when on the big or middle rings, but when I shift to the small ring the chain rides on the cage. Any workarounds for this? Am thinking praps an E-mount front derailleur mite be a solution.

 

[alfeng]

Am encountering probs attaching a front derailleur to a curved stoker seat tube. The curve shifts the cage downward towards the rear, so I have to raise the clamp in order for the cage to clear the big chainring. Not a prob when on the big or middle rings, but when I shift to the small ring the chain rides on the cage. Any workarounds for this? Am thinking praps an E-mount front derailleur mite be a solution.

What/(How many) gear combinations does the chain drag on the rear derailleur's cage?

How small is your granny?

Presuming you have a 30t, can you go to a 32t (which I think is more-typical-than-not on most Tandems) or even a 34t?

An E-mount front derailleur might work, but then you had better be using Campagnolo shifters because I don't think you'll be able to index Shimano Road shifters to a Shimano MTB derailleur UNLESS (meaning, I've done so with a pair of 105 shifters & an XT front derailleur) you were only using it on a Double (which you aren't) ...

OR, of course, you can use an E-mount front derailleur if you have a Flat Bar Tandem.

 

[norbikes]

the triple is a 48/38/30. The chain drags on all cogs when the chain is on the 30t ring. Since it's only a 5 speed freewheel I'm using friction shifters, stem-mounted. How big a chainwheel will an e-bracket f. der. accommodate? I think I've seen 48t capacity on some models.

What/(How many) gear combinations does the chain drag on the rear derailleur's cage?

How small is your granny?

Presuming you have a 30t, can you go to a 32t (which I think is more-typical-than-not on most Tandems) or even a 34t?

An E-mount front derailleur might work, but then you had better be using Campagnolo shifters because I don't think you'll be able to index Shimano Road shifters to a Shimano MTB derailleur UNLESS (meaning, I've done so with a pair of 105 shifters & an XT front derailleur) you were only using it on a Double (which you aren't) ...

OR, of course, you can use an E-mount front derailleur if you have a Flat Bar Tandem.

 

[alfeng]

the triple is a 48/38/30. The chain drags on all cogs when the chain is on the 30t ring. Since it's only a 5 speed freewheel I'm using friction shifters, stem-mounted. How big a chainwheel will an e-bracket f. der. accommodate? I think I've seen 48t capacity on some models.

Despite what you may read AND (therefore) what many people believe, you can easily use a Shimano MTB front derailleur with a 52t chainring ... maybe, a 53t.

I'm using a top pull XT (737) front derailleur with a 52/39 Road crankset on one bike.