Just introducing myself and sharing my experience with the Schwinn Tailwind, since there don't seem to be that many accounts out there with specific information.
At my last job I had an easy 3-mile commute to work (each way) that I biked often, but now it's gone up to 12.5 miles over hilly terrain, so I had been pondering getting an ebike that would let me stop driving again. My old mountain bike can do the commute, but it takes 70 minutes each way and leaves me sweaty and tired with a greasy pant leg, and my workplace doesn't have showers or a changing area other than the bathroom. Using my car is extremely tempting since it only takes 20 minutes that way.
I bought a Tailwind at Performance on a whim when I wandered in their store and saw they were on sale for $800 earlier this year. I had been researching ebikes enough to know that was a DEAL! I knew I couldn't hope to get what I needed at that price anywhere else, so I took the plunge and bought one. But overall I find the bike is underpowered for my commute and too slow to make it worthwhile.
The worst part is right as I'm approaching my work, I have to go up 160 feet at an almost 7% average grade. If I'm extremely miserly with the electric assist the entire rest of the trip I can keep the 4.2Ah battery from dying, but that doesn't happen often; the motor squeaks and moans on the hill then cuts out, leaving me to huff and puff to push the 50+ lb brick up the rest of the way. There are other less severe hills on the route where I get similar disturbing whining from the motor, and if I pedal with everything I've got I can almost keep it going fast enough to stay quiet. Of course, breaking a sweat was not what I had in mind when I bought this thing.
The commute does take less time now, I think my record is about 55 minutes. I'm still not satisfied, though, because I can go faster on the flat parts in my MTB! The motor stops assisting around 15 mph and leaves it up to me to pedal. Well, with a large upright bike and an 8-speed IGH I can only make it go so fast, probably topping out around 17 mph. It would be fine in an urban setting where everything is closer together, but if I were in that position I wouldn't need an electric bike.
I have minor gripes with taking the wheels off, but it's really not so bad once you've done it. The biggest problems are the lack of documentation that comes with the bike for how to remove each wheel, and the rather large number of tools required that makes it difficult to fix a flat on the side of the road.
It was an interesting summer with the bike, but I think I'll have to return it to Performance; it just can't do what I'm expecting of it. I did learn quite a bit about ebikes through owning this one and I feel like I am much more prepared to find something to suit my needs. I also had never owned a bike before that had full fenders, a chainguard/chaincase, or a frame-mounted wheel lock, all great commuter features that I'd like to see on my next ebike.
I wasn't really considering it, but since I see they aren't available at a low price anymore I'd be willing to sell it for a small profit. $900? It's size large (I'm 5'10") and in excellent condition, I still have all the keys. I'm in Maryland between DC and Baltimore, so if that's not near you we'd have to work out how to ship the thing. If you are local I can show you how to remove the wheels, but from your posts I'm guessing you could figure it out PM me if you want more details.
I had similar issues with top end speed on my RMartin that uses an internal 3 speed Shimano Nexus hub. I could pedal fairly fast once the motor cut out (~18ish mph), but I could only get about 20ish mph before the cadence made me look goofy.
Mine came with 18 tooth cog and I swapped it to a 16 tooth one (I ordered an 18 and 16 from JensonUSA) . I have plenty of hills, but most are not too bad, so I don’t notice the low end difference as much but I spend more time in second gear now instead of third, and my top end non goofy looking speed increased a couple miles a hour. I feel that my trips are about 1-2 mph faster with it.
Once the battery weakens up enough to where can’t make my daily commute, I’ll be looking at a kalkhoff. Expensive, but it should pay for itself in a year or so.