G gray198 Esteemed Pedelecer Apr 4, 2012 1,578 1,069 Apr 20, 2017 #21 Glad it was only a simple question (lol) Reactions: oldtom
D Danidl Esteemed Pedelecer Sep 29, 2016 8,611 12,256 73 Ireland Apr 21, 2017 #22 soundwave said: the bosch motor is 2.5 gear ratio so a 15t is the same as a 37t normal sprocket. Click to expand... Eo Woosh said: I also wonder if such arrangement (2.5 intermediate reduction stage) reduces the overall wear and weight of the gearbox. Click to expand... I suspect that it reduces the weight somewhat , otherwise there would be another reduction required in the electrical power and a bigger mass in the chainwheel. It probably allows the electric motor to spin faster
soundwave said: the bosch motor is 2.5 gear ratio so a 15t is the same as a 37t normal sprocket. Click to expand... Eo Woosh said: I also wonder if such arrangement (2.5 intermediate reduction stage) reduces the overall wear and weight of the gearbox. Click to expand... I suspect that it reduces the weight somewhat , otherwise there would be another reduction required in the electrical power and a bigger mass in the chainwheel. It probably allows the electric motor to spin faster
