Tonight I tried to figure out if my hub-geared bike is a sane choice USING THE POWER OF MATHS!<\/p>\n
For example, this guy<\/a> sounds pretty pleased to have had a “25-12 tooth cassette and 30 – 42 – 52 chainrings” to get up the hills of Devon.\u00a0 That means his “easiest gear” used a 30 tooth sprocket at the front and a 25 tooth sprocket at the back, and so one turn of the pedals turned the back wheel 1.25 times.<\/p>\n My hub gear bike came with a 44 tooth chainring and a 20 tooth sprocket at the back – a ratio of 2.2 by itself.\u00a0 But the hub gear itself<\/a> provides a ratio of 0.53 (easy) to 1.61 (hard).\u00a0 So the combination means that my easiest gear ratio is 1.16.\u00a0 Looks like I should have an even easier time uphill than Mr Derailleur.<\/p>\n What’s more, I think his racing bike has larger wheels (700mm = 27.5″) than mine (26″) which means that each revolution of his wheels makes him go further.\u00a0 Good news for him on the flat, but bad news for his hill climbing.\u00a0 To be truthful, I can’t figure out whether those measurements reflect the distance to the wheel rim or the outer edge of the tyre.<\/p>\n