Disc rotors on older, threaded hubs?

I'm planning on mounting a stoker-actuated disc on an older-model
tandem with a '70s-era Phil hub threaded for the Arya (sp?) drum unit.
That's the same thread as the freewheel side. Can one buy an adaptor
to six-bolt? Or... are these old-mod rotors still available anywhere?

I doubt that one could "adapt" it easily because, based on my
measurements, the existing threads are where the bolts would need to
go.

It may be time to change out the hub.

Jones... who always asks: why do it the easy way when, with a little
imagination, I can make the job *much* more difficult?

On May 30, 9:21*am, !Jones wrote:
I'm planning on mounting a stoker-actuated disc on an older-model
tandem with a '70s-era Phil hub threaded for the Arya (sp?) drum unit.
That's the same thread as the freewheel side. *Can one buy an adaptor
to six-bolt? *Or... are these old-mod rotors still available anywhere?

I doubt that one could "adapt" it easily because, based on my
measurements, the existing threads are where the bolts would need to
go.

It may be time to change out the hub.

Jones... who always asks: why do it the easy way when, with a little
imagination, I can make the job *much* more difficult?

I have an adapter from DT Swiss on our tandem, but I went back to rim
brakes. We warped rotor after rotor before I learned that tandems
ridden even in "easy" (not hilly) terrain can put out too much heat.

It might work as a drag brake in addition to rim brakes, but I'd
consider it unlikely and a marginal solution even if it appeared to
work initially.

Anyway, the adapter exists.

Good luck!

!Jones wrote:
I'm planning on mounting a stoker-actuated disc on an older-model
tandem with a '70s-era Phil hub threaded for the Arya (sp?) drum unit.
That's the same thread as the freewheel side. *Can one buy an adaptor
to six-bolt? *Or... are these old-mod rotors still available anywhere?

I was able to draw and dimension a print for such an adaptor. I
submitted it to a production machine shop for a bid, but I couldn't
justify the outlay.

The 44mm BCD puts the inner edges of the screws at a 19mm radius,
whereas the major diameter of the freewheel thread lies at about
17.5mm radius. That's pretty crowded.

Crappy Chinese scooter and electric bike makers have tackled this
problem (crappy band brakes fit to the hub on freewheel threads), and
they resolved the issue by making disc rotors with a slightly larger
BCD than IS disc rotors. You can find such threaded adaptors and
rotors he

http://electricscooterparts.com/brakes.html#diskbrakes

There's no reason in principle that you couldn't use a crappy Chinese
rotor with a decent disc brake, as long as the dropout-to-rotor
spacing was compatible. But 160mm is as big as you get in that
world.

Chalo