Originally Posted by
MikeyMK
Yeah. It's more a hub really, isn't it. I knew what i meant. It 'should' be an armless crank..
I've looked at that idea briefly, but she just doesn't need to contribute. I suppose it wouldn't be a bad thing for the involvement, but there are other things to consider with that;
For one, the crank is an overdrive - it will be turning around 1.42 times faster than the one on the front, because a 40T front crank will be turning the 28T chainring (his changes my 11-36T freewheel into the equivalent of 8-25T, therefore solving my problem of trying to get a Capreo freehub on an electric motor).
But i could gear her crank back down. Three chains and three BB's though.. well, it ain't gonna be a light bike anyway!
Also, she'll be sat on a long lay-back seat post, partially over the rear wheel, so her feet will be quite far in front of her even to reach the seat post - It'd condition her for using a cruiser bike i guess...
Hmm, this gives me the idea of using the stoker to sit there and just generate electricity with the pedals...
So... now just to shorten the butted frame by some 10ins...
Kids grow by about 10" a year... I'm not sure I'd mess with the frame unless there is no other choice.
If you put in the stokid config, then you could reverse it: 28/40T, and be back to a 1:1 ratio, or if you're a big time spinner, perhaps even more relaxed gearing.
It might be nice to get a freewheel in there somewhere, like the autoshift bikes use at the crankset.
I took my nephew out on a Tandem a few years ago. He didn't really want to do it, and did everything he could think of to make it difficult, including simply standing on the pedals and letting them push him up and down. Frankly, I couldn't feel it (noting, of course, that what goes up comes down).