N380 gearing.

weldinpatt

New Member
Hello all Nuvinci, interested folk. There seems voiced, the question of changing ratio under load. They don’t like it. The IGH, is not a derailleur, the gear changing technique is totally different. A momentary halt in pedal rotation coinciding with a brief twist of the rotary selector. Simple. Think like a Sturmey Archer IGH. Back off on the pedals or a gentle rock back and forth if stationary. If changing ratio requires the grip of a gorilla, your doing it wrongly.
Even at 380% ratio range, it isn’t that wide when compared to many derailleur setups. The way I deal with the gear/ road speed , is to alter the primary gear ratio so as to place the 380% range in the most comfortable position for the type of riding I do. Living in a hilly area my choice was to sacrifice top speed in favour of climbing ability. ( I still reach 15mph easily). With a 26t rear sprocket the primary ratio is 1.8-1, lower than the 2.0-1, recommended by Enviolo, but I recon their safe level is well on the safe side. My equation goes like this; (weedy me + 250w) = < (2x 1gorilla on a tandem).
A good after market accessory would be a two sprocket cluster and a two speed derailleur . In effect creating a high and low range. SRAM, and SA, have created such in the past and was most successfully utilised on the folding Brompton.
I run an X-RD3 @ 1.8, and an X-RD5-(w) @ 1.75, well under the manufacturers recommendations but again no problems so far with 650 miles and 1400 miles respectively. There are no hills I cannot climb, and that’s in Snowdonia.
E bikes don’t need loads of different gear ratios, that was in the old, human only power days. The days of narrow power bands and very little torque, ended with the introduction of electric motors. As did the.need for zillions of extra gears or the repetition of the same ratios in different places across the cassette .
The Nuvinci, and IGH, hubs in general present an excellent stable chain line, requiring infinitely less maintenance and a massively longer life. I’m sure this it the way, all the best e bikes will develop in the future. Come think about it I’ve never seen a Hayabusa, sporting derailleurs.