Paul Thumbie Convertors

I am considering buying some of these, but nearly everyone says they require the barcon shifters.
As far as a can see there is no real reason not to use the standard downtube levers (which i already have). Does anyone know if any down tube levers will work, if some will work, or none at all?
I have a theory that they recommend the barcon ones for the replacement down tube adjusters that are included.
Anyone have any ideas or experience?

Thanks

I have some on my RC200 (see sig) but dont know enough about road gear to help any further.

If by down tube adjusters you mean the cable barrell adjusters that came with the bar con shifters, then no, the pauls dont use them. They have their own barrell adjusters.

The downtube ones will work.

But:
1) The barcons have a flush base, whereas downtube shifters usually have a curved base to fit round the frame tube....judicious filing may be necessary to get them to fit snugly.
2) Downtube levers are a bit longer, you may find that they are not in reach of your thumb at the extremes of their rotation.
3) The levers are a lot thinner at the tips and have a think about whether you feel comfortable crashing into the end.

Standard Shimano down tube shifters should fit as the barcons and the downtubes both have the same mounting bits

I thought the downtube levers had a curved back spacer plate that fitted over the boss ?

The barcon mounts had a dummy boss, but a flat baseplate.

the spacers are interchangeable