Tandem rear hub conversion with drum brake

[Jonah]

Excuse my ignorance on such matters but does anyone know if you can simply remove a drum brake from one wheel and attach it to a new wheel with a hub motor in? (Like you could with a disc rotor) Or is it built into the hub?

 

[Swizz]

Excuse my ignorance on such matters but does anyone know if you can simply remove a drum brake from one wheel and attach it to a new wheel with a hub motor in? (Like you could with a disc rotor) Or is it built into the hub?

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No unfortunately not. That looks like an Arai drum brake >>> https://www.precisiontandems.com/arai.htm They were often fitted the rear of tandems as a drag brake for long descents as they were good at dissipating heat.

 

[vfr400]

No you can't. If it's a screw-on type, there are some motors that have the extra thread on the left size for screw-on brakes.

 

[Swizz]

I probably should add that if removing it by fitting a hub motor, it would be prudent to replace it with an alternative as your electric kit will add weight - maybe a large diameter disk brake, although you will need the frame modifying to accommodate one.

 

[Jonah]

Thanks for speedy responses.

 

[Bikes4two]

Firstly, I am a tandem rider (Santos Double travel) and have toured extensively in hilly terrain with camping kit on board.

Our tandem is not fitted with an Arai drum brake but instead, has a cable operated disc brake (can't recall the size at the mo) as an alternative 'drag' brake and it works very well and we have never over-heated either the disc or the normal rim brakes (Magura hydraulics), but then again we've never ridden the alps either,

So as an alternative to the Arai, you could consider fitting your desired rear hub motor and employ a disc 'drag' brake instead.

Given that your rear forks may not have the bosses for a disc brake caliper, then there's the alternative of fitting a front hub motor which seems to be popular with tandem conversions.

(for non tandem riders, the 'drag' brake is used when a tandem is going down hill to 'share' the heat load generated by braking. If only the rim brakes are used, there is the risk that under long and continuous braking conditions in very hilly terrain, e.g. alpine descents, the rims heat up and cause a tyre inner tube to burst or worse).