Originally Posted by
EvilV
It sort of goes against my own simplistic understanding of what goes on in pedaling. ....... I HAD thought that shorter cranks would require that more force be applied to maintain a specific power at the rear wheel, since the leverage would be shorter and hence more pressure would be needed. However, I had not thought about the amount of angle the knee joint needs to operate through, and to be honest, I can't just visualise that at this moment. I'm going to have to sit down with a pencil and do some drawings to work out how it affects the knee.
Fortunately, I don't have many knee twinges currently, but I am mindful of the consequences, so I'm keen to have as little unnecessary stress on them as possible.
Their "side effects" are interesting too. I find it easier in busy situations not to have to coordinate my static leg positions when I'm going around bends, particularly at night, & where there are high kerbs or rough road edges. Potentially they should also be a bit lighter, but I haven't found them easy to buy at a sane price. I checked the Netherlands web page where I bought mine, but he doesn't seem to stock them now. I'd like another set, maybe 145, or 150, so I suspect I'll need to buy from the USA, eg.,
http://www.gaerlan.com/bikeparts/parts/crank/crank.html
but that may mean more hunting for chainrings, as I really need 130 BCD, not 110, since the rings are like dinner plates :-) I fitted a 53 tooth ring yesterday, which was nice for more top speed, but back to more strain going up hills!
Here's another possible source:
http://bikesmithdesign.com/
When I bought the 155 cranks, I thought I'd try them on my Strida 3.2, & also remove its freewheel so I could try out a fixie :-)
However, I didn't, as it dawned on me I'd have to raise the saddle yet another 15 mm or so, & to get maximum power I already have my saddle at probably a bit too high, which means I have to take care which way to lean when I'm on a well cambered road, to put my foot (well, tiptoe actually :-)) down! To get the best out of a Strida, I feel saddle height is really vital. Just a bit too low means much more fatigue going up steep hills.
Cranks are indeed a very interesting subject, so it'd be nice to see your sketches & ideas when you've thought them out please :-)
I'm really pleased you're enjoying your Strida, a great fun bicycle to have.