So I've been looking forward to getting an e-bike one of these days and I've been wondering whether to go 36v or 48v... i won't even consider 24v cause of all the hills we have in southern california. I've tested out a 36v system before... and just this past weekend I tried a 48v system that my friend got! w00t!!!
I was curious and excited to know how much faster this 48v was going to be. Right off the bat I noticed the bike was faster and the top end had to be quite a bit higher because I can feel the wind resistance so much more than 20mph... That is the good part... it feels very zippy and fun and just goes probably like 5mph faster, but I can't say cause there was no speedometer.
This was good in the beginning but after a couple miles I realized that bicycling was not the same anymore, like at all.
The reason I say this is because with the 36v, pressing full throttle, the gearing on the bike was still very useful and I could pedal continually and help ease the load off the battery very effectively.
But with the 48v... the gearing was almost useless, I was just sitting there pressing the throttle all the way like usual. Only when going uphill was I able to pedal and be of some help. Otherwise I felt like I wasn't even getting any exercise cause pedaling was useless. I tried pressing 3/4 throttle consistently so my speed would lower but that's just weird and it's not intuitive and you want to just press it all the way all the time.
So... I think i'm going to go for a 36v system, it'll cost less, the bicycle will still be a bicycle i can pedal and exercise with and at least I'll be within the legal 20mph limit as well probably. Those are my priorities so to speak (price and exercise/health benefits!). If you want to mountain bike off road and up lots of hills, then for sure 48v will be for you, but i'm always on the streets and trying to commute by bike is a lot of fun.